



Produced by Nick Hodson of London, England




Sant of the Secret Service
Some Revelations of Spies and Spying.
By William Le Queux
Published by Hodder and Stoughton Ltd, London.

Sant of the Secret Service, by William Le Queux.

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SANT OF THE SECRET SERVICE, BY WILLIAM LE QUEUX.

PREFACE.

ABOUT GERRY SANT.

To those who, like myself, have moved in the Continental underworld of
spies and spying, the name of "Sant of the Secret Service" is synonymous
with all that is ingenious, resourceful, and daring.  In the
Intelligence Departments of London, Paris, Rome, and New York, the name
of "Sant of the Secret Service" is to-day one to conjure with.

Cheerful, optimistic, and the most modest of men, Gerry Sant has seldom
spoken of his own adventures.  The son of a certain nobleman who must
here remain nameless, and hence the scion of a noble house, he has
graduated through all stages of the dark and devious ways of espionage.

Our first meeting was ten years ago, in the tribune at the Battle of
Flowers at San Remo, where, to be exact, we were fellow-members of the
committee, and it is because of our old friendship, and the fact that we
have been fellow-spies up and down Europe, that he has permitted me to
write down these intensely absorbing memoirs of exciting and unrecorded
adventures in defeating the Hun.

William Le Queux.

_Devonshire Club, London, 1918_.

CHAPTER ONE.

ESPIONAGE IN PICCADILLY.

The place: The kerb in front of the Criterion at Piccadilly Circus.  The
time: Five minutes past three on a broiling afternoon in July.  As an
idle lounger, apparently absorbed in contemplation of the ceaseless tide
of human traffic that ebbed and flowed, I stood gazing along the famous
London thoroughfare.  In truth, I was keenly alert to every movement
about me, for I had extremely important Secret Service work in hand.

I took out a cigarette, tapped it mechanically, and slowly lit it
preparatory to crossing the road to Shaftesbury Avenue, when suddenly,
from the procession of hurrying vehicles, a taxi detached itself and
drew up to where I stood.  I caught a momentary glimpse of a woman's
eager face half shaded by a fashionable hat.  The next moment I was
seated beside her, and we were bowling smoothly along Piccadilly.

"_Ah, mon cher Monsieur Gerry_!" exclaimed my pretty companion.  "Well,
has anything serious occurred?" she asked breathlessly, with her
fascinating French accent.

"Listen, my dear madame, and I will explain," I replied.  "Hecq has sent
me over from Paris in order to see you.  I arrived only this morning,
and am returning this evening.  Something very serious is on foot, and
Hecq wants you to get leave of your chief, and come over to help us."

And here perhaps I may introduce my companion a little more fully.
Gabrielle Soyez was a female agent of the British Secret Service, who
had distinguished herself in her profession times out of number, both
before and since the outbreak of war.  Dark-haired and handsome, she
inherited from her French father that seemingly irresponsible and
irrepressible gaiety which so many of her countrywomen exhibit.  From
her English mother, no doubt, she had acquired the sterner, almost
masculine, qualities which her femininity concealed but did not
suppress.  A splendid linguist, speaking several European tongues to
perfection, she could, on occasion, pass as a native of some other
countries.  And one of her most amazing feats had been a journey right
across Germany from Holland in wartime, in the character of a young
German fraulein travelling to take up a position as governess in East
Prussia.  Added to her linguistic abilities, she possessed nerves of
steel and a quick, subtle brain, which saw the real significance of many
an almost unnoticeable incident.  Nothing was too big or too small for
her attention.

I knew her well.  I had worked with her in more than one affair of
international importance, and it was at my suggestion that Armand Hecq,
the astute chief of the French International Secret Service Bureau, had
applied for her to assist in the difficult task that lay before us.

"Something fresh this time?" queried the _chic_ little lady, as we drove
along.  "And, pray, who has applied for me?"

"I have," was my reply.  "A very difficult task is before me, involving
the risk of many lives, and you are the only woman I know in whom I can
place absolute trust."

"Except Doris, eh?" she flashed out, turning to me with a quizzical
smile.  She was referring to Doris Rae, my well-beloved, who lived with
her mother in a quaint old timbered house buried deep in Worcestershire.
In the stress of my war-work I had seen her but seldom for the past two
years, for I was constantly on the move, but the bond between us was
none the less true and perfect.  And I nodded to my companion, with a
laugh.

The time slipped by as I gave Madame Gabrielle her instructions.
"To-day is Tuesday," I said as we parted.  "I shall expect you on Friday
in Paris at the Orleans station.  The express for Bordeaux leaves at
eight twenty-seven.  Watch for me, and enter another compartment of the
train without speaking.  Somewhere on the journey I will contrive to
hand you your passport."

"But what is the nature of this inquiry, Monsieur Sant?"  Madame
Gabrielle broke out.

"Well, to be frank," I replied, "the French Admiralty report that the
enemy has established a new secret submarine base off the Spanish coast.
We are out to find it, and, what is more, to carry out reprisals on the
pirates."

Madame, seeing a good chance of a desperate adventure, grinned with
satisfaction.  "_Tres bien_," was her only comment.

So we parted, she to her hotel, I to wile away the few hours that
remained to me before the departure of my train from Victoria.  I went
along to "White's," in St James's Street, for a cup of tea, and, after
buying some packets of Dutch cigarettes--which I purchased with a
purpose--looked in at my own flat in Curzon Street.  The place seemed
close and musty nowadays.  After a brief conversation with Doris over
the telephone, I started out to walk to the station.  But I was not to
get away from London without a startling surprise.

I have never been able satisfactorily to account for the adventure which
befell me as I strolled through St James's Park on my way to Victoria.
Whether I was the subject of an attack by a mere footpad, or by some
tool of our enemies who knew of my work and mission, I cannot say.  But
one of those strange premonitions, which come so frequently to men who,
like myself, carry their lives in their hands, as all spies do,
undoubtedly saved my life.

Since I left Madame Gabrielle the weather had changed.  Heavy clouds had
rolled up, as if a storm were threatening, and it had grown very dark.
Having time to spare, I had intentionally made a detour from my direct
road, and I was in a lonely pathway when something, I know not what,
made me suddenly face round, with every nerve and muscle braced for
instant action.

I was only just in time.  From the grass at the side of the pathway a
man leaped at me.  In the gloom I caught sight of his upraised arm and
the flash of a knife.

It is hard to catch the practised student of jiu-jitsu unawares, and
that fascinating form of self-defence has been one of my special
hobbies.  Like a flash I jumped in to meet the charge of my assailant.
Before his knife could descend my right arm was crooked into his and I
had his wrist in the grip of my left hand.  Flinging my whole weight
forward, I wrenched his right arm savagely backward and downward.  With
a half-stifled scream of pain the man toppled over backward, his head
striking the ground with a crash that left him senseless.

Here was a pretty coil!  I dared not wait to give the man into custody,
for that would have meant police inquiries and endless publicity, to say
nothing of missing my train and a fatal delay to my important mission.
And just now I could not afford publicity.  So I decided to leave him
alone, to take his chance and make his own explanation, if necessary.
Picking up his knife, I thrust it deeply into a flower-bed, and,
stamping it well down with my heel, hurried on to the station, and was
soon on my way to France.  Who and what my assailant was I never heard.
But I pondered over the incident a good deal on my journey, for it may
have meant that my mission was already known.  Still, this was unlikely,
so I merely decided to keep an extra sharp look-out.

On Friday, at the hour I had appointed with Madame Gabrielle, I passed
the barrier and walked along the platform of the Orleans station in
Paris, where in the summer twilight the express, with its powerful,
constantly exploding locomotive, stood ready for the long run across
France to the Spanish frontier.  I bought a copy of _Le Soir_ at the
bookstall, and while doing so my eye fell on a rather shabbily-dressed,
insignificant-looking little man who apparently was lounging absently
about.

Every "natural" spy, if I may use the term--and I think I am one of
them--possesses a large measure of that intuition which is somewhat akin
to a woman's power of frequently jumping to a perfectly correct
conclusion without the trouble of logically working a problem out.  The
things which matter in our calling are often seemingly the most trivial.
There was nothing about this shabby little stranger to call particular
attention to him, yet from the moment I saw him I felt instinctively
that in some way my lot and his were bound up together.  And, try as I
would, I was unable to shake off that feeling.

How far I was correct the sequel will show.

As I entered the train I saw Madame Gabrielle, carrying her dressing-bag
and followed by a porter with her hand luggage, pass the window of my
compartment and enter a first-class carriage nearer the front of the
train.  Her eyes met mine as she passed, but she gave no sign of
recognition.  Of the little shabby man I saw nothing, though I kept a
sharp look-out, and I concluded at last that he had left the platform.

All through that night the train roared onward by way of Orleans and
Tours down to Bordeaux.  I slept, as I usually do, but dreamed in a
manner quite unusual with me.  Throughout the night my sleeping thoughts
were harassed by that shabby little man who had, I seemed to feel no
doubt, witnessed my departure with a perfectly definite object.

Perhaps I may be permitted to say here a few words about myself.

I am a cosmopolitan, the subject of no country, though through my
parents my sympathies are more English than anything else.  British when
in England, I am a Frenchman in France, an Italian in Italy; I can be a
German in Germany, or a Spaniard in Spain.  The explanation is, of
course, that I have led a wandering life, being of almost every
nationality by turn and nothing for long.  My adventures have been
facilitated by the fact that I happen to have known several languages
from my earliest childhood.  Whoever is born in Smyrna, as I was, has
truly a ready-made profession in the matter of languages.  At ten years
old most lads in Smyrna can speak four or five tongues, and, in
addition, I developed early a peculiar gift for languages, and an
insatiable desire to speak as many as possible.  Thus, all the principal
European languages became equally familiar to me, and I speak them all
almost as well as if each were my mother tongue.

It was to this gift of languages that I owed my entrance to the ranks of
the French Secret Service.  When still quite a boy I found myself,
through a peculiar chain of circumstances, a homeless outcast in Paris.
I had been tramping the boulevards, and, tired and hungry, had sat down
with my back resting against a big tree.  I was half asleep when I was
roused by two men talking in a queer Dutch patois which I happened to
understand.  I suppose they thought they were alone, or, at any rate,
that no one who might overhear them would be likely to understand their
lingo.  They were laying their plans for a daring raid on the house of a
famous Paris banker.  Boy as I was, the situation fascinated me, and as
night drew on I shadowed the men and was the means of bringing about
their capture under dramatic circumstances.  They proved to be a
much-wanted pair of international crooks.  The affair brought me some
credit with the French police, and in the end, finding out the value of
my linguistic achievements, they began to employ me on small
undertakings.  I did well, was gradually entrusted with more important
work, and was finally given regular employment.  Such was my
introduction to the world of espionage.

But to return to my story.  At six o'clock on Saturday morning we drew
into the great Bastide station at Bordeaux, where the train had half an
hour's wait.  I alighted with all the other dishevelled passengers, to
scramble to the buffet for our _cafe an lait_ and _brioche_.  In the
scramble I pushed past Madame Gabrielle, who looked somewhat untidy
after an obviously sleepless night, and as I did so I slid into her hand
a little parcel screwed up in brown paper.  In it was a note containing
certain instructions, together with her passport, bearing her photograph
in the name of Gabrielle Tavernier, described as "variety artiste."  So
perfectly self-possessed was she that, although she had not seen me--I
had pushed up behind her--she never even turned her head as the note
slipped into her hand.  It was this self-control which made her an
invaluable helper; nothing ever seemed to take her by surprise, or to
betray her into a hasty word or action.

I had just taken my first sip of coffee, when, glancing across the big
restaurant, I caught sight, among the crowd of third-class passengers
who were thirstily quaffing their bowls, of that same shabby little man
whose presence on the platform in Paris had given me such an unpleasant
shock.  Evidently he had managed to elude my observation, and had joined
the train without my seeing him.

I had been beaten at my own game!  I had thought I had shaken him off,
and his presence was an intensely disagreeable surprise.

There was, of course, no very obvious reason why he should not be a
perfectly harmless fellow-traveller, but I was absolutely convinced in
my own mind that his presence here in Bordeaux was in some way connected
with my mission, and that it boded me no good.

Slipping from the station, I hurried across to the Place du Pont, where
I knew there was a public telephone.  I knew, of course, the password
which "cleared the lines" for official messages, and in less than ten
minutes I was in communication with Armand Hecq, at his house at St
Germain, outside Paris.  To him I briefly explained how matters stood.

"I quite understand, Sant," he said.  "Leave matters to me and continue
your journey.  _Bon voyage_!  I shall read the _Matin_ every day."

Then I rang off and hurried back to the station, just in time to catch
the train as it drew out for the "Cote d'Argent," "the Silver Coast," as
the French call that beautiful Biscayan seashore between the estuary of
the Gironde and the golden sands of Spain.

Through the miles of flat pine woods of that lovely marsh country called
the Landes, where the shepherds stride on their high stilts and watch
the trains go by, we sped ever south, by way of the ancient town of Dax
and on to sun-blanched Bayonne.

Now we were rapidly approaching the Spanish frontier, and I wondered
what was transpiring between Hecq, in Paris, and the officials at
Hendaye, the last French station, where the agents of police were
stationed to prevent German spies from entering France by that
particular back door.

I was soon to learn that Hecq had not been idle.  Late in the afternoon
the train pulled up at Hendaye, and, as it seemed to me, had hardly
halted at the platform when I caught sight of my shabby little man being
escorted from the station in the relentless grip of a couple of stalwart
French gendarmes.  Evidently Hecq was taking no chances, and I breathed
a sigh of relief at the removal of my incubus.  It turned out later that
the shabby little man was a clever German spy, and, of course, he paid
the invariable penalty.

Very soon the train moved across the long bridge over the river to Irun,
and beyond.  Thus we arrived at length at San Sebastian, the Brighton of
Spain, at that moment in the full height of the sea-bathing season, and
crowded with a motley assembly of Europeans of all nationalities, with,
of course, a liberal sprinkling of desperate adventurers ever on the
look-out for any crooked undertaking that promised plunder and profit.

Our plan, of course, was to avoid the slightest appearance of hurry.
Anything in the shape of undue eagerness and haste might well mean
arousing the suspicions of the Spanish authorities, who, being neutral,
might very easily arrest us both (especially if I were recognised, as
was always possible) as secret agents of the Allies.  I entered an open
cab and drove to the old Hotel Ezcurra, where in past days I had eaten
many a meal and drunk many a bottle of choice wine.  Madame Gabrielle,
in accordance with our arrangements, had gone to the Hotel Continental
in the Paseo de la Concha, the establishment most patronised by the gay
society of Madrid, who loved to show off their Paris gowns and to
exhibit, too often in the most plebeian fashion, the wealth which had
come to them as a result of the war.

For three days I remained at the Ezcurra, so pleasantly situated behind
the lovely lime-trees in the Paseo de la Zurriola, and to which the
smart, chattering officers of the unwarlike garrison, in their grey
uniforms and peaked caps, resorted every evening.  I had previously
decided upon the character I would assume; it was that of a Dutch
theological student.  I gave out that I spoke no Spanish--of course I
spoke Dutch--and pretended a vast interest in visiting the ancient
churches--San Vincente in the old town, Santa Maria at the ascent of the
Mont Urgull, and the beautiful old churches of Hernani and Azpeitia, as
well as the prehistoric rock caves of Landarbaso.  All the time, of
course, I was keenly on the alert, my ears ready for any scrap of
information that might chance to come my way.

One day I had been visiting the little village of Azcoitia, the
birthplace of Loyola, the founder of the Jesuits.  At a pleasant old
_fonda_ close by I had dropped in for a dish of _olla_, that kind of
stew so dear to the Spanish palate, when, at a table near by, I noticed
two middle-aged men who quite obviously were not Spaniards.  Apparently
they were Italian, for they spoke that language, and their clothes had
obviously been made by an Italian tailor.  But I noticed instantly a
fact which at once aroused my suspicion--the boots they wore were of
German manufacture!

Men's nationality and habits are often betrayed by their footwear, and
my observations on the boots and shoes of people of both sexes have
seldom led me wrong.  Indeed, I always pay the closest attention to
clothes, for nothing will so completely "give away" an assumption of a
pretended nationality so promptly as an error in dress.  Every scrap of
clothing I was wearing had been bought in Holland, and I was sure of my
disguise.  My suit I had purchased of Buijze, in the Kalverstraat in
Amsterdam.  The pseudo-Italians, carefully got up as they were for the
part they were playing, had forgotten one important item, and I had
little difficulty in coming to the conclusion that they were really
Germans.  I decided to keep a sharp watch on them.  The question was:
were they watching me?

I dawdled over coffee and cigarettes till they rose to leave, when I
paid my bill with the intention of tracking them back to San Sebastian.
Unfortunately I was baulked immediately.  Fond of exercise, I had walked
out to Azcoitia; the two strangers had driven, and I had the
mortification of seeing their carriage start for the city.  It was
useless to attempt to follow; they were out of sight long before I could
have hoped to get the slow-moving Spaniards to provide me with a
carriage.  There was nothing for it but to return as I had come, and
keep a sharp eye open for the mysterious strangers.  It was evident
that, if they really knew me, they must have satisfied themselves that
for the present, at any rate, I was actually idling, and that there was
"nothing doing."

Returning to the Ezcurra, I wrote out an advertisement which I sent to a
certain address in Paris.  I knew that it would appear immediately in
the "personal" column of the _Matin_.  It was in French, but the English
translation read: "Isis.--Mother has fortunately passed crisis, and
going on well.--Felox."

This advertisement, I knew, would appear both in London and Rome, as
well as in Paris.  To the uninformed it would appear innocent enough,
but certain persons in the Allied capitals knew that "Felox" was myself,
and, reading the announcement, would be reassured as to the progress of
my secret mission.

Next day I spent idling about the beautiful blue bay of La Concha,
taking my evening _aperitif_ at the Casino, and after dinner I spoke to
Madame Gabrielle over the telephone.  I told her, of course, about the
two mysterious strangers, giving her as full a description as possible
of their appearance, and urging her to keep the keenest watch for them.

When I returned to the palm-lounge, a page-boy brought me a telegram
addressed to van Hekker, the name by which I was known at the hotel.

Opening it, I found that it had been sent from London.  It was a cryptic
message which read:

"_Fontan remains here.  Goods marked C.X.B. arrived fourteenth,
twenty-three cases.  Awaiting samples second quality_."

Without giving the least sign that the telegram was of any special
interest, I read it through and carelessly slipped it into my pocket.
But the news it contained was startling.  It put an entirely fresh
complexion on affairs, and it meant that I must act without delay.
Unless within twenty-four hours or so I secured a triumph, my mission
would be unsuccessful, and in all probability some two thousand human
lives would pay the price of my failure.

It was absolutely essential that I should discover without delay the
identity of "Fontan," for there lay the crux of my difficulty.  With
that knowledge in my possession I should have more than a chance of
success; without it I was merely a blind man groping in the dark.

CHAPTER TWO.

SPYING ON SPIES.

The bold course was the only one possible.  I walked straight to the
Correo Central, and, entering the _poste restante_, inquired casually
for a telegram addressed to the name of Fontan.

"It was called for half an hour ago," was the gruff reply of the little
old Spaniard at the counter, who shot a quick look of suspicion at me,
wondering, no doubt, how it came about that a second inquiry should be
made for the same telegram.  I bit my lip, but tried to appear
unconcerned, and, after dispatching another message, went out filled
with chagrin at having missed my objective by so narrow a margin.  The
time left me for action was growing desperately short, yet, rack my
brains as I would, I could think of no way out of my difficulty.

But my suspense was not to last long.  As I walked slowly back to the
Ezcurra, my heart gave a sudden leap as I recognised, walking parallel
with me on the opposite side of the road, one of the two mysterious
"Italians" whom I had encountered a few days previously in the little
_fonda_ at Azcoitia.  He was walking at about the same pace as myself,
and I very quickly realised that he was carefully "shadowing" me.  But
that was a game at which two could play!

Turning into a shop where there was a public telephone, I rang up Madame
Gabrielle at the Continental, swiftly explained the circumstances to
her, and implored her to hurry to meet me, so that she could take off my
hands the task of watching the "Italians."

Purposely I set my steps toward the Continental, making a sharp turn
from my direct road to do so, and my suspicion that I was the object of
the "Italian's" attention was instantly confirmed.  He turned at once to
follow me, though apparently with so little of set intention that no one
whose suspicions had not been aroused would have dreamed that he was
being shadowed by a clever hand at the game.

Ten minutes later a grave-looking Spanish lady, wearing an ample
mantilla, came slowly towards me.  I was eagerly on the look-out for
Madame Gabrielle, but I confess that for a moment I never suspected that
she and the Spanish lady were identical.  Indeed it was not until she
had attracted my attention by a slight but peculiar flip of the hand,
which was one of our recognised private signals, that I realised who she
was, so perfect was the disguise.

However, my course was easy enough now; all I had to do was to indicate
the "Italian" to her, and I knew I could safely leave in her hands the
task of finding out all there was to know about him.

I had crossed the road and the "Italian" was some fifty yards behind us.
As Madame Gabrielle approached I turned down a side street, and, when I
judged the "Italian" must be near the entrance, walked smartly round the
corner to meet him.  I had judged the distance well; we came into
violent collision, and with every indication of helplessness that I
could assume I fell headlong into the roadway.

Instantly the "Italian" was all helpfulness and apologies.  He assisted
me to rise and helped me to brush away some of the dust with which I was
covered.  Of course I could not, for this occasion at least, speak
Italian, but the language of signs was sufficient, and at length I left
him apparently much distressed, and started for the Ezcurra, limping
with an ostentatious painfulness which I hoped would effectually
convince my antagonist, firstly, that I was really hurt, and, secondly,
that I had not the smallest suspicion of his real identity and object.
We signalled good-bye with every appearance of cordiality.

I took good care not even to look round on my walk back to the hotel.  I
knew the "Italian" would be safely under the observation of Madame
Gabrielle, and that I should get the information I wanted in good time.
My spirits rose.  I felt sure that at length I was on the right track.

Returning to the hotel, I volubly explained my dirty and dishevelled
appearance in full hearing of a small crowd of idlers in the lounge.  I
did not know whether among them there might not be another agent of our
enemies, and, by way of concealing my suspicions, I spoke warmly of the
essentially Italian courtesy of my late antagonist.  It came out
afterwards that I had done a good stroke of work.  The lounge did
contain an enemy agent who was watching me, but so naturally was I able
to speak that he actually reported that I had obviously not the smallest
suspicion of the real calling of the mysterious "Italian."

Until I received some word from Madame Gabrielle there was absolutely
nothing that I could do, and I passed hour after hour in an inward fever
of impotence and anxiety, though outwardly, I dare say, I was cool and
unconcerned; one does not wear his heart upon his sleeve in the Secret
Service!  Dinner came and I ate with an appetite, well knowing that at
any moment a call might come which would tax my physical and mental
powers to the uttermost.

Having finished my dinner, the big Swiss porter came into the room and
handed me a note, remarking in French: "This has just been brought by a
boy, monsieur."

Inside it I found a plain visiting-card of the size used by gentlemen.
There was nothing else.

Here, indeed, was the call to action.  That plain visiting-card was a
signal from Madame Gabrielle that she was hot on the scent, but that
either because she feared she might be under suspicion, or would not run
the risk of her message falling into the wrong hands, she could not
write a letter.

In any case it was an urgent call for urgent help.  The hunt was up!
Towards us, urged by the full power of her twin screws, a British liner
was being driven at top speed by her giant engines; awaiting her,
securely hidden in some sheltered spot I had yet to find, was one of the
undersea assassins of our enemy.  And the lives of two thousand men,
women, and children were at stake.  At last the hour for swift, dramatic
action had come.

Certainly matters had now assumed a very critical aspect.  I hurried out
along the broad, tree-lined Paseo, where the moon was now shining
brightly over the Bay of San Sebastian, to the Hotel Continental.  Here
the gold-laced _concierge_ told me that Madame Tavernier had left about
an hour before.

"Did she say where she was going?"  I inquired.

"Yes, to Santander," replied the _concierge_; "the Hotel Europa she gave
as her address, so that we might forward her letters; she said she had
not expected to leave so soon."

The meaning of the visiting-card was now plain.  Evidently the
resourceful Madame Gabrielle had made some important discovery.  She
dared not communicate with me, but, of course, she knew I would make
inquiries, and for this reason she had left her address with the hotel
porter.  But why had she gone to Santander?  Cost what it might, I must
find the answer to that question.

"What about the gentleman who was with her?"  I asked the porter, making
a blind shot to try to find out something.

"Gentleman?" he queried.  "Madame was alone in the omnibus except for an
Italian gentleman, who went to catch the same train to Bilbao."

"An Italian gentleman!"  I echoed.  Here might be the key to the
mystery.  "He was about forty--pale, with a dark-cropped moustache and
rather bald--eh?"

"Yes," replied the man, "that is Signor Bruno."

"What about his friend?"  I asked.

"He left for Madrid by the early train this morning," was the reply.

Matters were now becoming clear.  Evidently the second "Italian" had
cleared off, leaving "Signor Bruno" in charge of the developments of the
plot.  I had now to find "Bruno," and through him to get on the track of
"Fontan."

Pleased with my success, I slipped a few pesetas into the willing hand
of the _concierge_ and left the hotel, directing my steps back to the
Ezcurra.  Why had Madame Gabrielle left for Santander when obviously San
Sebastian was the real centre of the plot?  The cryptic telegram I had
received told us that.  It was, in fact, a spy message sent from
Holland, which had been intercepted by the French Secret Service and
duplicated to me; the real message, of course, had been duly handed to
"Fontan" at the post office in San Sebastian.

How to get to Santander was now the problem.  The last train had gone.
But after half an hour's deliberation I hit upon a plan which at least
held out a good promise of success.  I returned to my hotel and gave
strict orders that, as I was not feeling well, I was on no account to be
disturbed until noon the following day.

It was just two o'clock in the morning when I rose and exchanged my
Dutch-made clothes for another suit so glaringly redolent of the
American tourist that no one, seeing me in them, would have associated
me for a moment with the demure and retiring Dutch theological student,
whose absorbed interest in old churches had been the source of many a
friendly joke at the hotel.  A false moustache helped further in the
metamorphosis, and when I looked at myself in the glass I felt tolerably
certain that I should pass even a close scrutiny without arousing
suspicion.  Still, I meant to take no chances.

The hotel was now profoundly silent.  Here and there a single electric
light glowed, left for the convenience of visitors who might be moving
about late; but there was no night-porter, a fact which I had previously
ascertained.

Carrying my boots in my hand, I stole noiselessly to a little side door,
and, dropping a few spots of oil on the lock and bolts to obviate any
sound of creaking, I opened it noiselessly and stepped out into the
old-world courtyard.  The moon was high and it was almost as light as
day.  But I had little fear of being observed; the courtyard could not
be seen from the street, and at that hour there was little likelihood of
anyone being about.

The hotel garage was my objective.  I had noticed a day or two before
that among the visitors staying at the house was a young fellow who
possessed a swift and powerful "Indian" motor-cycle.  I decided that the
urgency of my business amply justified what might have looked like theft
had I been detected.

Drawing from my pocket the bunch of skeleton keys which I usually carry,
I succeeded after a few minutes of perplexity in opening the sliding
door of the garage.  With the help of my pocket flash-lamp, I picked out
without difficulty the machine I wanted and filled up the ample petrol
tank with spirit from one of the many tins lying about the garage.  I
was ready at last for my race to Santander.

After a hasty glance up and down the road to make sure no one was in
sight, I wheeled the machine through the courtyard, under the old
archway and out on to the broad roadway, closing and locking the door of
the garage behind me to avoid suspicions being aroused.  I knew the
removal of the machine would probably not be noticed for a day, or
perhaps two, as the young owner had gone off with a companion on a
fishing excursion.

When I had reached some distance from the hotel I lit the headlamp,
started the machine, mounted and rode away.

From the map I had carefully committed my route to memory, and I let the
powerful machine "all out."  Travelling at considerably over fifty miles
an hour, with the engine pulling as smoothly as a watch, I first went
along the winding sea road, then away into the fertile valley of the
Oria and by the village of Aguinaga, down to Zarauz, which was on the
Biscayan beach again.

The early morning came, balmy and beautiful, as, covered with dust, I
shot down the steep winding road into the chief centre of the life of
Santander, that spacious promenade known as "The Muelle," with its
luxuriant gardens, from which I could see the blue mountain ranges of
Solares, Valnera, and Tornos beyond.

Once in the gardens, I dismounted, and, watching for an opportunity when
I was unobserved, I wheeled the motor-cycle into some low bushes, where
I abandoned it.  Thence I strolled down to the dock, where in a narrow,
unclean street I soon found a dealer in second-hand clothes, of whom I
purchased a most unsavoury rig-out.  It was evident that the man was
well used to proceedings of this kind, and, as his business quite
clearly depended upon his knowing how to hold his tongue if he were paid
for it, I paid him generously, and was quite assured my secret would be
safe with him.  He took me into a dark little den at the rear of his
stuffy shop, where he helped me into my disreputable disguise, adding
here and there a skilful touch which showed me plainly that he was no
novice at the business.

Arranging with him to keep my own clothes until I called again, I
sallied forth, quite confident that I had effectually destroyed all
traces of my identity, and evaded the men who had been watching me at
San Sebastian.  To further my plans I bought in the market a basket such
as street hawkers carry and a quantity of oranges.

Having done this, I sought out a quiet corner, and, sitting down on the
pavement, began eating some bread and olives I had bought, just as any
other equally disreputable Spanish pedlar might have done.  I could
hardly help laughing at the incongruity of my surroundings--Gerald Sant,
to whom pretty well every fashionable hotel in Europe was intimately
familiar, taking his breakfast of bread and olives seated on the
pavement in a Santander slum.

But my breakfast was only a part of the work I had to do.  Taking a
cigarette from my case, I carefully slit it open, threw away the
tobacco, and wrote a message upon the paper.  Then, rolling the thin
scrap, I placed it within a quill toothpick, plugging the sharpened end
with a scrap of orange peel.  Afterwards I inserted the quill into the
centre of one of the oranges, carefully covering up the puncture and
drying it.  Inside the quill was the translation, for Madame Gabrielle's
benefit, of the "Fontan" cable.

Then, in the guise of a poor fruit-seller, I sought out the hotel in the
Calle Mendez where I knew that Madame Gabrielle had arrived.  I knew, of
course, that she would be eagerly on the look-out for me, and that, as
she would guess I should be disguised, she would station herself in some
prominent place, where I could see her at once.

Evidently, however, she did not expect me so soon.  No doubt she had
looked up the trains, and, knowing that I must have missed the last one
the previous night, would naturally conclude that I would arrive about
midday.  The stratagem of the bicycle had evidently not occurred to her.

I drifted slowly backwards and forwards in front of the hotel, and after
a time had the intense satisfaction of seeing the "Italian," Signor
Bruno, come lazily out and seat himself in a comfortable chair in the
ample porch.  It was obvious that he was expecting someone, for his eyes
constantly searched the long, straight roadway.

A moment later Madame Gabrielle, daintily attired in the latest Parisian
mode and carrying a sunshade, strolled leisurely into the porch.  She
was accompanied by a lady, obviously Spanish, with whom she had no doubt
scraped a breakfast-table acquaintance.

Despite the need for hurry, I could not help being amused at her evident
failure to recognise me.  Twice or three times I slouched past the
hotel.  The next time I caught her eye, and, as I made the almost
imperceptible signal, I saw the answering flash of intelligence in her
eyes.

"What lovely oranges!"  I heard her say to her companion.  "I really
must have some."

And she rose indolently and came down the steps to me.  As if I had
heard and understood nothing, I placed myself directly in her path,
saying in a loud, whining voice in Spanish: "Buy some Naranjas, lady--do
buy some.  Very fine Naranjas."

Taking out her purse, Madame Gabrielle handed me a coin, and, as she did
so, swung her sunshade round so as to interpose it directly between the
"Italian" and myself.  With the coin came a tiny folded note, which
passed so swiftly into my hands that there was no prospect of the
"Italian" observing it.

"What beautiful fruit!" she said aloud; adding in a faint whisper: "Be
near the fountain in the gardens in half an hour."

"Thank you, lady," I whined in Spanish in true hawker fashion, handing
her the oranges.  As I did so, I tapped one of them three times, taking
care that she observed the action.  It was enough for her swift
intelligence.

The next moment, touching my battered hat in respect, I slouched off, my
basket on my arm, while she, apparently a summer visitor, carried the
fresh-cut fruit, each with a leaf attached, just as dozens of others
were doing when out for a walk before luncheon.

I watched her return to the hotel, of course, to examine her oranges.
Lazily drifting along the road, I made my way to the gardens, and was
soon stretched indolently in the sunshine within easy sight of the great
fountain.  Under cover of my battered hat I read Madame Gabrielle's tiny
note.  It had evidently been written to be ready for a hurried meeting,
and ran:

"_They will meet to-night on the coast road a mile out of the town near
the big oak.  Bruno and Fontan will be there at ten-thirty.  The attempt
is to be made shortly.  I dare not risk speaking_."

But it was essential we should speak, and I had my plan cut and dried.

When Madame Gabrielle came in sight, I was startled to see the "Italian"
following her.  Could his suspicions have been aroused, I wondered?
Hitherto Madame Gabrielle had been shadowing him; were the positions now
reversed?  I noticed she looked pale and anxious; it was evident
something untoward had occurred.

Long before, we had taught ourselves to send messages in the Morse code
by finger movements, the raising or dropping of a finger representing
the dots and dashes of the code.  Thus so long as we could see each
other's hands we could communicate rapidly and silently; failing direct
sight, we had only to tap out the message.  Gabrielle seated herself
negligently on a seat and produced a book, which she read industriously,
quite unconscious to all seeming of the disreputable fruit-seller lying
asleep on the grass, his face shaded from the hot sun by his
broad-brimmed hat.  The "Italian," in the meantime, had seated himself
on a seat a few yards away.

Whether he suspected me I do not know; probably not.  But beneath the
brim of my hat I could see Madame Gabrielle's delicate hand and arm
flung carelessly across the back of the seat.  Her fingers, screened
from the Italian's sight, rapidly ticked out their message.

"I got your note; it confirms what I have found out.  The attempt is to
be made to-morrow night.  Bruno has been talking with a dark,
sailor-looking man who, I think, must be Fontan.  I overheard them from
the balcony outside their room.  I suppose I must have made some sound,
for Bruno came out hurriedly on to the balcony.  He looked as if he
could kill me, and ever since he has been following me.  I dare not
attempt to follow him when he leaves the hotel this evening.  The
arrangement may be a blind; you must watch him all you can.  I will risk
everything to get a message to you if I hear any more, but I am afraid I
can do no good now."

"You have done very well," I signalled back.  "Go to the hotel and get
on the 'phone to the British Consul.  Tell him to recall Jeans by
wireless at once for instant action.  I shall stake everything on
to-night.  After that, go straight back to San Sebastian, and let it be
clearly known in the hotel that you are going.  We must throw Bruno off
the scent."

Madame Gabrielle signified that she understood, and soon after got up
and moved listlessly away.  She had no sooner turned the corner than the
"Italian" rose and followed her.  Of me he took no notice whatever, and
apparently he had not the least suspicion that Madame Gabrielle and I
had been in communication.

I was burning with impatience to be off, but I dared not hurry.  The
"Italian" was evidently no fool.  I lay still, apparently asleep, but
keenly on the look-out.  A few minutes later the "Italian" suddenly
returned; evidently he meant to make sure I had no sort of association
with Madame Gabrielle.  Had I foolishly got up at once as soon as she
went, his suspicions would almost certainly have been aroused.  But I
lay still, seemingly asleep, and, after a scrutinising gaze at me, he
turned away, obviously satisfied.

The course was clear now, always assuming that the rendezvous arranged
between Bruno and the supposed Fontan was real and not pretended.  But
that I had to chance.  As a matter of fact, the spot was well chosen for
any business connected with the Huns' submarine activities.  It was in a
lonely spot, the road ran near the edge of the cliffs, and the coast at
that point was studded with deep coves where a lurking U-boat could lie
concealed without much fear of detection.

During the afternoon I saw Madame Gabrielle leave for the station in the
hotel omnibus, the "Italian" following in a cab.  So anxious was he to
make sure she had gone that, as I heard afterwards, he actually followed
her to the train, and did not leave the station until after it had
started.  Probably his suspicions were lulled by the pretty little
Frenchwoman thus leaving the field apparently clear for him; but, be
that as it may, he later walked straight into our trap.

CHAPTER THREE.

BERLIN'S SECRET CODE.

Towards sundown I wandered along the coast road for some three miles,
until I caught sight of a great crooked tree, which stood remote from
the road at the head of a narrow cleft, through which a steep track
descended to the beach.  I had very little doubt, when I had thoroughly
examined the place, that it was an ideal spot for the Hun purposes.  The
pebbly beach sloped steeply into the water; it was evident that deep
water came close in to the shore.  The spot was far from any human
habitation; the road was a lonely one, set back at this point at least a
mile from the edge of the cliff.  I knew that the superstitious
Spaniards were not fond of being about the cliffs at night, and that if
the U-boat pirates were really using the coast as a secret base, they
would, if they took ordinary precautions, run very little risk of
detection.

My first task was to find a hiding-place.  After some deliberation I
selected a thick clump of brushwood which grew about half a mile from
the point at which the track from the beach rose to the top of the
cliff.  Lying down at full length, I felt satisfied that I could see
without being seen, and, pulling out the excellent pair of night-glasses
with which I had taken the precaution to equip myself, I prepared for my
vigil.

Just as sunset was darkening into night I caught sight of two men coming
along the road.  Through my small pair of powerful glasses I instantly
recognised one of them as the "Italian."  The other, no doubt, was
Fontan.  Their figures showed black and sinister in the last gleam of
the sunlight.  They were walking quickly, and Fontan, if indeed it was
he, carried in his hand a well-filled sack.

As they drew near they left the road and made straight for the edge of
the cliff, disappearing into the cleft almost beneath the very branches
of the big tree.  It was now or never for me, and, loosening my
automatic in my pocket, I cast all prudence aside and raced at top speed
for the cliff.

Arriving at the edge, I flung myself flat on my face and peered over.
Below, to my intense gratification, I could see assembled on the sands a
dozen sailors in German uniforms, while only a few yards from the shore
lay a big German submarine, its conning-tower and fore and aft guns
showing clear of the long grey hull, which lay almost awash.  The crew
were being exercised along the sands, while Fontan was handing to an
officer a quantity of fresh vegetables, with a packet of letters and
telegrams, from the sack.  Close by, the "Italian" and another officer,
evidently the captain of the U-boat, were in earnest talk.

The light was failing rapidly, and soon it became too dark to see more.
A lantern twinkled on the beach, and I could plainly hear steps and
voices ascending the rough path to the top of the cliff.  It was
essential I should hear more, therefore I took the desperate course.
Swiftly climbing into the tree, I laid myself down at full length on a
big branch which jutted out over the path.

Preceded by a sailor bearing a lantern, three men came up the path.  Two
of them I knew to be the "Italian" and the captain of the U-boat.  The
third was Fontan, at whom I particularly wanted to have a look, for
something in his walk reminded me of someone I had failed definitely to
recall.

As the sailor reached the top of the cliff he turned and swung the
lantern so as to show the last few steps of the rugged path.  Its rays
fell for a second upon the face of Fontan, and I nearly fell from my
perch with amazement.  Willi Bernhard, by all that was wonderful!  One
of the Kaiser's most expert spies, who was head of one of the
departments of the Koniggratzer-strasse, posing in Santander as a humble
boatman.  No wonder I had failed to recognise him until I saw his face!

"No need for me to come any farther," said the deep voice of the U-boat
captain in German.  "We shall lie here until midnight to-morrow, and
will expect you at sundown with the latest instructions.  I only want to
make sure the others are ready at their stations.  And then," he added,
with a cruel laugh, "good-bye, _Athabasca_!"

The _Athabasca_ was the liner I had come out to save!

I gritted my teeth with rage at his brutal callousness, and when I
thought of the two thousand or so lives dependent on the _Athabasca's_
safety I could barely restrain myself from emptying my revolver into his
head.  That, however, would have been merely suicide, so I bided my
time.

The "Italian" and Bernhard, as I may as well call him now, wished the
captain _au revoir_ and started to walk briskly to Santander; the
sailors returned to the shore.  Once the way was clear I wasted no time.
I am a good runner, but never in my life have I covered three miles as
quickly as I did that summer night in my dash for Santander.

I was elated beyond measure.  For I had quite obviously dropped right on
to the submarine supply-base, the existence of which had for months been
a practical certainty.  And, further, I had discovered the identity of
"Fontan," the German spy who was acting as the "post office" of the
U-boats, and supplying them with all necessaries.  It now remained only
to smoke out the pirates' nest and destroy the whole brood!

That cryptic telegram which was delivered to me at the Ezcurra in San
Sebastian had been sent to Bernhard--in the name of Fontan--at the
_poste restante_ in San Sebastian and called for by the "Italian."  It
was originally sent out by wireless, intercepted by the International
Bureau, and retransmitted to me for my information and guidance.  In the
code of the maritime department of the German Secret Service at Kiel,
when decoded it read:

"_Fontan remains here_."  (The following message is sent to Fontan at
your _poste restante_.) "_Goods marked C.X.B._" (the wireless call
letters for the British liner _Athabasca_, from New Zealand, bound for
London) "_arrived_" (meaning due to arrive) "_fourteenth_" (to-day was
July 12th), "_twenty-three cases_" (twenty-three o'clock Continental
time, in our time 11 p.m.).  "_Awaiting samples second quality_"
("samples" in the spy code meaning submarines--"second quality"
German--"first quality" meaning British).

Thus the submarine commander was informed of the coming of the great
liner and was lying in wait in the calm, secluded cove, ready to pounce
out and sink the great ship with two thousand souls on board, including
a large number of New Zealand troops.

Racing into Santander, I made for the British Consul's house, presenting
so disreputable a figure that it was only with the utmost difficulty
that I secured admission to the Consul himself.

"Has Jeans arrived?"  I asked breathlessly, and, hearing that he was on
his way at full speed, I told the Consul what I had learned.

Clearly it would be touch and go, but we had a little time in hand.  The
submarine would not leave the cove until after midnight on the
thirteenth--to-day was the twelfth--so as to be just in time to place
herself across the path of the oncoming liner.

About seven o'clock next evening, lounging in the garish Cafe Suzio,
with its noisy crowd, I saw a tall English traveller in grey tweeds
saunter in.  After he had swallowed a drink, I rose and went out, and he
followed at once.  It was the commander of the British submarine 85, and
on receipt of my wireless he had come full speed to Santander.  At that
moment his boat was lying off the port, skilfully screened behind a big
British tramp steamer that was being used as a decoy.  He had come
ashore, apparently from the tramp, but really from his own boat, which
had submerged the moment he left it.

"Well, Sant," he said eagerly, "you've made a grand discovery.  I got
your wireless off Finisterre last night, and came here full speed.
Wilson is outside Bilbao, and Matthews at Gijon, both waiting.  I have
sent out a message to the squadron, and we hope to make a big bag.  But
we'll get this friend of yours in the cove first, anyhow.  You'll come,
of course?"

I eagerly assented, and we went down to the water's edge, where the
tramp steamer's boat was lying in charge of two men whose merchant jack
rig-out hardly concealed the purposeful British bluejacket.  We were
soon on board the tramp.  A few minutes later the submarine rose
noiselessly to the surface, close alongside, and we went on board.

"Now for the cove," said Jeans, as we dropped below.

Crawling along dead slow in order that the noise of our propellers might
not betray us to the enemy, we approached the cove.  By this time it was
dark.  A mile from the cove, screened by a promontory of rock, we rose
noiselessly to the surface.  A collapsible Berthon boat, containing half
a dozen armed men, put off to guard the approach to the beach, and once
more we submerged and made for the cove, showing only six inches of our
periscope above the rippling waves.

There was just enough moonlight for our purpose, and as we drew near we
were able to make out the enemy submarine, lying just awash, and
presenting a magnificent target.  Very few of the crew were on shore;
obviously they were getting ready to leave.  We could make out the
captain, walking up and down with two men that we knew must be the
"Italian" and Bernhard.

Jeans swung our ship slowly into position; the torpedo crew grouped
themselves round the bow tube and we waited the exact moment.  It was
necessary that most of the crew should be on board, for our
landing-party dared not risk a possible fight on Spanish soil, and if
only one man escaped we should lose our chance of a big bag of the
pirates, since a warning that the plot was discovered would at once be
sent them by wireless.

At last the men began to go aboard.  They were using a small boat which
would hold only three men, and, as luck would have it, only the captain
at length was left on the shore, talking to the "Italian" and Bernhard.
The small boat, with only a single sailor in it, was being pulled ashore
to fetch him when Jeans gave the single word "Fire!"

Our boat reeled slightly to the shock of the departing torpedo.  At the
range of a few hundred yards, under such circumstances, a miss was out
of the question.  A few seconds later a ponderous "boom!" blanketed by
the waters, told us our torpedo had exploded and, gazing eagerly into
the mirror of the periscope, I saw a blood-red flash as the enemy ship
apparently flew to pieces in a confused column of spray and smoke.  She
must have been ripped open from end to end and, of course, disappeared
instantly, with every soul on board.

"Now for the rest," was Jeans's laconic remark, as we swung out to the
spot where we had put the landing-party ashore.

They were there almost as soon as we were, bringing with them the
captain, Fontan, and the "Italian."  Dazed with the surprise and shock
of the explosion, they had made no resistance to the rush of our men.
The captain, indeed, had recovered himself sufficiently to throw into
the sea a case of papers, but a sailor had dived and recovered it, and
to our intense delight we found it gave details of the exact plans which
had been made for the destruction of the _Athabasca_, with the precise
points at which five successive U-boats were to lie in wait for her.
This was luck indeed.

Soon we were on our way to intercept and destroy the first of the
lurking Huns.  Running at full speed on the surface, we kept our
wireless busy, and soon had the satisfaction of knowing that our
dispositions had been made to circumvent the enemy's plots.  Finally,
nearing the scene of action, we submerged.

I need not here describe the tension of the hours which followed.  Amid
the steady hum of the machinery, Jeans was constantly busy, now scanning
the surface of the sea through our periscope, now giving a watchful eye
to every detail of the submarine's complicated machinery.

At last, just as the first grey streaks of dawn showed on the horizon,
he called me to the periscope, and, reflected in the mirror, I saw
faintly the thin plume of smoke from the funnels of the approaching
liner.

We knew that somewhere in that zone an enemy submarine lay awaiting her
prey.

For half an hour we were keenly on the alert, as we watched the
approaching liner.  The captain had been warned by wireless, and we knew
there would be no lack of watchfulness on board.  We could imagine the
gun-crew standing at their stations, every eye strained for the first
sight of the enemy.

It came at last.  Almost directly between us and the liner a German
U-boat thrust her periscope out of the water and launched a torpedo.  We
saw the big liner swing suddenly to her swiftly ported helm, and we
heard afterwards that, owing to her steersman's promptness, the torpedo
missed her bow by not more than a few feet.

Just as the liner turned the submarine broke water--why, I never could
understand.  Probably her commander was too supremely certain that his
shot had gone home, or else some error in navigation had brought him to
the surface earlier than he intended, for obviously it was his duty to
remain submerged until he was sure his work was done.

Be that as it may, it was his last mistake.  As the grey whale-back of
the submarine rose above the water the gun of the _Athabasca_ spoke.
The first shot was over, the second short.  Before the third was fired
we had also bobbed up suddenly, and the U-boat found herself the target
of two antagonists.

There could be only one end to such a fight.  Almost simultaneously the
third shot of the _Athabasca_ and our first rang out, and both shells
found their mark.  One struck the conning-tower fair and square, blowing
it clean away; the other crashed into the upper part of the hull,
tearing a huge gap, and in a few seconds the enemy vessel had sunk with
all hands, leaving only a flood of oil on the heaving surface of the sea
to show where she had disappeared.

Next day I was on the Sud Express for Paris, while Madame Gabrielle,
whom I had recalled by wire, followed me a few hours later.

From Hecq in Paris I learned the full sequel of our adventure.  No news
of the affair ever leaked out to the public.  But it appears that, owing
to the discovery of the plans from Kiel in possession of the submarine's
captain and our wireless messages, French destroyers and British
submarines, operating together, had within twelve hours cleaned out the
pirates' nest, sinking four more submarines and taking nearly sixty
prisoners, most of whom are now behind barbed wire in Wales.

CHAPTER FOUR.

THE HIDDEN HAND IN BRITAIN.

"Ah! my dear Hecq--you have now set me a very difficult task--very
difficult indeed!"  I found myself saying a few weeks later, after I had
mastered, with a good deal of trouble, a formidable dossier which had
been laid before me by the astute chief of the French Secret Service,
now promoted, by the way, to be chief of the International Secret
Service Bureau of the Allies.

Though the time had been short since my return from Spain, much had
happened.  At length "unity of command" in contra-espionage work had
been realised as an absolute essential for securing a definite mastery
over the incessant plottings of the Huns, and, with the cordial goodwill
of all, Armand Hecq--whose brilliant abilities had given him a
commanding position--had been unanimously chosen for the much coveted
post.

"I admit it is extremely difficult," said the short, grey-bearded, alert
little man, knocking the ash from his excellent cigar, leaning back in
his cane deck-chair, and regarding me with an amused smile.  "It is so
difficult that I confess I do not see my way at all clearly.  For that
reason I have put the matter before you."

"There can be no doubt about the seriousness of the affair," I said.
"The French Service have done very well so far, and so have our friends
in London.  We are quite well aware that during the past few weeks there
has been an amazing recrudescence of German espionage, both here and in
England, and even Whitehall is seriously alarmed.  There is good reason
for believing that working drawings of the new British trench-mortars
have, by some means, been smuggled over to Germany.  How they got out is
a complete mystery, for the control at all the ports has been stricter
than ever.  Yet van Ekker has managed to get through to Holland a
message from Berlin which leaves very little doubt as to the fact.  It
is undeniably serious, for the new mortar is a wonderful production, and
I happen to know that it was intended to be one of the grand surprises
in the Allies' spring offensive."

Hecq grunted, and I paused.  Then I went on saying:

"We have a pretty good idea of the traitor in the department concerned,
and he is now safely under lock and key.  Unfortunately the mischief was
done before he was even suspected, and the closest inquiries have failed
to unearth any of his associates who would be regarded as in the
slightest degree doubtful.  It looks very much like a case of a hitherto
thoroughly reliable man yielding to a sudden and overpowering
temptation, while the real culprit--the man who pulled the strings--
remains undiscovered.  No doubt Count Wedell and his precious propaganda
department have a first-class man at work, and they have so cleverly
covered up the tracks that the method of their latest coup remains a
mystery.  It is perfectly obvious that the subterranean work of Germany
is even now proceeding in France, Italy, and Great Britain."

"Exactly, _mon cher_ Sant.  And you must take this particular matter in
hand at once, and try to discover at least one of the fingers of what
your good friends across the Channel call so appropriately `the Hidden
Hand.'  For myself, I feel quite sure that at last, after much seeking,
we have alighted on the source of the whole affair, so far as England
and France are concerned."

Our conversation had taken place at Armand Hecq's house out at St
Germain, beyond Paris.  I had come post-haste from Lausanne, where I had
been engaged with Poiry--an ex-agent of the Paris Surete--upon another
matter.  An urgent telegram from Hecq had warned me that the new
business was most important, hence I had lost no time in answering his
summons.

It was a warm afternoon, and we were seated out on the terrace
overlooking the pretty garden, which was the hobby of the most
remarkable and resourceful secret agent in all Europe.

To outward seeming Armand Hecq was a prosperous Parisian financial
agent, whose offices in the Boulevard des Capucines, opposite the Grand
Hotel, were visited by all sorts of persons of both sexes.  None,
excepting those "in the know," suspected that these handsome offices,
with the white-headed old _concierge_ wearing the ribbon of 1870, were
in reality no mere financial establishment, but the headquarters of the
international espionage of the Allies.  None realised that the crowds of
"speculators," who flocked thither in the pursuit of ever-elusive
wealth, included among them dozens of men and women who day by day
carried their lives in their hands in their never-ending warfare with
the unscrupulous and resourceful agents of Germany.  None dreamed that
to the busy staff finance was a mere side-line; that their real interest
was not the daily fluctuations of the Bourse, but the thread of Hun
intrigue which ran through all the crowded life of the gay city, and was
nowhere stronger than in the department of finance.

"Now, Sant," said Hecq abruptly, after we had sat silent for a few
minutes while I ran over in my mind the essential facts of the new and
tangled case.  "You have seen the photographs and the _dossier_, and you
understand the position.  What is your opinion?"

"There can be but one," I answered leisurely.  "Before the war, Jules
Cauvin, of Issoire in Auvergne, was a struggling corn-merchant.  He has
since, in some unaccountable way, blossomed out into a man of wealth,
and has purchased an important estate with money which has come from
some mysterious source.  Constant payments appear to reach him from a
firm of motor-engineers somewhere in England.  In his sudden prosperity
he has bought a villa at Mentone, where he lives during the winter with
his wife and family, and he is often seen at the tables at Monte Carlo.
Among those who have stayed with him at the Villa des Fleurs was the
Russian Colonel Miassoyedeff, who was recently hanged as a spy of
Germany.  There can be only one conclusion from all this."

"Ah! my friend.  I see you have mastered the essentials," said Hecq
approvingly.  "Now Cauvin and all his friends are under the strictest
surveillance; the question is how we are to secure evidence to convict
him of the espionage he is undoubtedly concerned in.  We can arrest him,
of course, at any moment; he has no chance whatever of getting away.
Every letter he sends or receives is opened and photographed, yet, up to
the present, he has been too clever for us.  If he were put on trial for
espionage to-morrow, not even his friendship with Miassoyedeff would
prevent him from being acquitted.  We have no evidence against him
whatever, beyond the fact of his sudden wealth, and that, even in these
times, is not enough."  And Hecq looked at me with an appeal in those
soft, strange eyes of his.  I could see that the case of Cauvin
presented itself to him as supremely important, and that it must be
solved if we were ever to grapple successfully with the mysterious,
deadly influence whose workings we could feel and trace all around us,
but the real wielder of which appeared constantly to slip through our
fingers.

"I quite understand you," I said, sipping the little glass of Cointreau
he had offered me.  "There is only one thing to be done.  We must find
that finger of the Hidden Hand in England."

"Exactly, my dear Sant," exclaimed my chief, with a quick gesture of
approval.  "We seem to be losing ground day by day.  Why?  At all costs
the position must be retrieved.  You will want Madame Soyez to help you.
Let me see; she is at present in England.  I sent her across only a
week ago to make some inquiries.  Excuse me a moment while I speak to
Guillet," and he left me to go to the telephone.

Monsieur Guillet was his private secretary, who controlled his
"financial office" in the Boulevard des Capucines.

A few minutes later he returned, saying: "Madame is to-day at the
Midland Grand Hotel in Manchester.  Presuming that you wish to meet her,
I have told Guillet to telegraph, asking her, if possible, to meet you
to-morrow night in London."

"No," I said at once.  "That won't do.  We cannot begin to work in
England yet.  I must learn a lot more about this interesting person
Cauvin, who has so mysteriously acquired a fortune.  Then we will begin
to probe matters across the Channel.  Recall Madame Gabrielle here and
we will set to work.  But it will be extremely difficult.  The
investigation of the Hidden Hand in England has always met with failure,
so far as the principals are concerned.  We have caught one or two of
the minor tools, but the master-mind has always eluded us, although the
British Secret Service is most excellent."

"Ah, _mon cher_ Sant, there I agree most cordially with you.  The world
little dreams of the astuteness and resourcefulness of our colleagues at
Whitehall.  One day it will know--and it will be greatly surprised.
Very well, I will order Madame Gabrielle to come direct to Paris."

Again he rose, and during his absence I once more glanced at the
formidable dossier concerning the wealthy Jules Cauvin, who was so well
known in the gay night life of Paris, whose smart wife was one of the
leaders in the social world, and who had recently established a hospital
out at Neuilly, where his wife and daughter worked unceasingly on behalf
of the wounded.

According to one report, the suspected man was in the habit of
entertaining certain high officials of the State at his fine house close
to the Etoile, and he had several bosom friends in the Admiralty.  Such
was the present position of a man who only five years ago was a
struggling corn-merchant in rural Auvergne.

I lit a cigarette and reflected.  By the time Hecq had returned I had
hit upon the rough outlines of a plan.

"First of all," I said, "you must call off the surveillance on Cauvin.
I must have a free hand in the affair, and the Surete must not interfere
in any way.  If Cauvin gains the slightest suspicion we shall certainly
fail.  Secondly, I must have a good man to assist me.  Aubert did
extremely well in the case of Marguerite Zell, the dancing woman who
came from The Hague; I will have him.  I shall leave Paris this evening.
Tell Madame Gabrielle to come home and wait till I return, and to hold
herself in readiness with Aubert."

Hecq nodded his assent, but did not ask me a single question.  That was
what I liked most about him; he never asked one how he intended to
proceed.  His trust, when it was given, was complete; he expected
results, and did not bother about mere details.  Yet, when his
assistance was asked at a difficult point, he was always completely at
the service of his employees.  He knew I had no particular affection for
the Surete, because in one important case they had bungled, and brought
me to disaster which nearly cost me my life.  So he merely shook hands
and wished me good luck.

Twenty-four hours later I arrived at the Hotel de la Poste, in Issoire,
a dull, remote little town in Auvergne, and next morning set about
making inquiries regarding Jules Cauvin.  First of all, I looked up the
entry of his birth at the Prefecture, which showed that he was the son
of the village postman of Champeix, seven miles from Issoire.  I found
out also that his father had been imprisoned for seven years for thefts
of letters.

It was necessary to make many inquiries without arousing suspicion,
therefore I was compelled to spend several days at my task.  I made some
interesting discoveries, for naturally the entire neighbourhood was
familiar with Cauvin's rise to wealth, and he had been put under that
microscopic observation and discussion which is so marked a feature of
provincial life everywhere, but especially in France.

I chanced upon a retired butcher named Demetz, in whose debt Cauvin had
been to the extent of nearly two thousand francs.  Demetz had been on
the point of suing for the money when, to his intense surprise, Cauvin
called one day with a bundle of thousand-franc notes in his hand, and
threw out three, saying gleefully: "The extra thousand is for interest,
my dear friend.  I invented an improvement in automobile engines a year
ago and patented it.  A big firm in England has taken up my invention,
and my fortune is made."

Naturally enough, the retired butcher had been keenly interested in
Cauvin's sudden wealth, and had tried to question him about it.  But the
postman's son was too wily to be drawn.  He declared that the invention
was a secret, that it would revolutionise the motor trade, and that the
English syndicate which had bought it meant to spring it upon the market
as a complete surprise.

I soon found out that the man Cauvin was not popular.  True, he flung
his money about, and there were few local institutions which had not
benefited by his largesse.  But there is no population in the world so
suspicious as the French provincial, and it was evident that the
ex-postman's son had entirely failed in his prosperity to win either the
affection or the confidence of those who had known him in his earlier
and humbler days.

Demetz voiced the prevailing suspicion.  "Where does his money come
from, monsieur?" he asked me.  "From a motor invention--bah!  What does
Jules Cauvin know about motors?  He had hardly ever been in one before
he grew so suddenly rich.  There is something mysterious about it all."
But it was evident that even Demetz had not the least inkling of the
real truth, and, of course, I did not breathe a syllable of it to him.

The matter was of extreme urgency, and I did not allow the grass to grow
under my feet.  I had promised Doris to spend a week with her in
Worcestershire, but this was impossible.  I knew, however, that she had
long wished for a trip to Mentone, so I sent her a wire, asking her to
come with her mother and meet me there.  A few hours after I got the
reply I wished for, and the following afternoon I alighted upon the long
platform at Mentone.  Two days later I was joined at my hotel by Doris
and her mother.

In Mentone, of course, my objective was the Villa des Fleurs.  I
particularly wanted to have a good look round the interior of that
interesting house.  Cauvin, of course, was away, and the house was shut
up, but I learned that it was being looked after by an old woman, the
wife of the gardener, and accordingly I hired a _fiacre_ and, with Doris
as my companion, drove out to the Villa des Fleurs.

On the Cote d'Azur the weather was stifling.  Driving up the white,
winding road of Castellar, we found the olives and aloes dry and dusty,
and the land parched and brown.  The Riviera is not gay in the dog-days.
At last we arrived at the Villa, a great, recently built house of the
flamboyant, new art style, its green shutters closed, and the whole
place silent and deserted in the burning sun.  Roses and geraniums ran
riot everywhere, but the gardens were kept spick and span, as became the
winter _pied-a-terre_ of a wealthy man.

I posed as an Englishman who wished to view the Villa, with the object
of becoming its tenant next winter, having heard from a friend of
Monsieur Cauvin that he might wish to let it.  Doris, I assured the old
gardener, a white-bearded man in a big straw hat and blue apron, was my
sister.  He took the bait readily enough, and handed me over to the care
of his wife, by whom we were conducted over the house.

The house was most luxuriously furnished, and it was evident that
popular rumours, for once, had not exaggerated Cauvin's wealth.
Everything was in splendid taste and bore the unmistakable _cachet_ of a
famous Paris firm of experts.  Cauvin, evidently, was no fool; he had
committed none of the absurdities of the average _nouveau riche_, but
had wisely given experienced men _carte blanche_.  The result was a
mingling of luxury and good taste which certainly could not have been
expected from the son of a village postman.

CHAPTER FIVE.

THE PERFUMED CARD.

We passed from room to room, chatting freely with the old Frenchwoman,
who garrulously told me everything I wanted to know, and showed not the
least reluctance to discuss her master and his affairs.

I had previously warned Doris to be on the look-out for anything of
interest, and, pleased with the idea of helping me, she was keenly on
the alert.  I was soon to have good reason to bless the lucky
inspiration which had led me to fetch her to Mentone at a time when most
people prefer to give it a wide berth.

After visiting a number of rooms, we came at last to the front entrance,
and the aged housekeeper seemed to think we were leaving.  But I had not
yet caught sight of Cauvin's private room, and I knew that unless I saw
that my journey would be fruitless.

"It is a very nice house," I said to our guide, "and the gardens are
beautiful.  But I have much writing to do, and there does not seem to be
any room which would serve well as a study."

She hesitated obviously.  "Well," she said slowly, "there is monsieur's
private room, but it is locked.  If monsieur desires it, I will fetch
the key."

"I might as well see it," I said, as carelessly as I could.  "I must
have some private den of my own," I went on.

The old dame shuffled off for the key, and I gave Doris a special hint
to keep her eyes wide open.  When the old woman returned she led us
directly to Cauvin's private room, a good-sized apartment, furnished
something after the pattern of the library of the ordinary English
house.  I noticed immediately that it had double doors; evidently Cauvin
had good reasons for making sure that there should be no eavesdropping
when he was at home.  Leading from it was a large salon, upholstered in
pale blue silk, and the old woman passed into this in order to open the
sun-shutters and admit the light.

In the window of the library was a big American roll-top desk, which
stood open and was rather dusty.  The green blotting-pad remained just
as the master of the house had left it, and near it lay a pile of
miscellaneous and dusty-looking papers.

I was glancing round when I was startled by a faint, gasping sob, and,
looking round, saw with alarm that Doris had dropped into a chair,
apparently faint.  The old woman had rushed to her assistance.

"It is nothing--only the heat," murmured Doris faintly.  "Please get me
a glass of water."

The old woman hurried away, and, much concerned, I bent over Doris.  I
had no idea that her illness was anything but real, and I was surprised
when she said crisply but quietly, "Now is your chance."

Then I realised her purpose and began a hurried examination of the desk,
keeping my ears open for any sound of the old woman's return.  But I
could find nothing.  Evidently Cauvin left little to chance.  The
drawers of the desk were not even locked, and I soon concluded that I
had drawn a blank, and that the key to the mystery I was bent on solving
must be sought elsewhere.  Of course I was not surprised.  It was not in
the least likely that Cauvin would leave incriminating documents in his
winter quarters, but in the work upon which I was engaged it would never
do to miss the opportunity that might be afforded by the momentary
carelessness which is the ever-besetting peril of even the cleverest of
rogues.  As events proved, we were to learn once again the truth of the
old adage that no man can be wise at all times.

When the old lady returned with water Doris soon "recovered," and
assured the volubly sympathetic dame that she was quite herself again.
As we stood for a moment saying farewell, her quick eye caught something
which I had overlooked.

"Why," she said, "here is an invitation to a wedding in England!"  And
she picked up from a small side table, where it lay in a china bowl, a
card printed in silver ink--an invitation, as she said, to a wedding,
and printed in English.

"Has Monsieur Cauvin many English friends?"  I asked the old
Frenchwoman, hoping that something useful might slip out.

"_Non, monsieur_," she replied.  "I do not think so; I have never seen
English letters come, and you are the first Englishman who has ever been
here."

I glanced at the card with an interest I took care to conceal.  It had
been issued six months before by the brother of the bride, a certain
Agnes Wheatley, and invited "Monsieur et Madame Cauvin" to be present at
her marriage to Captain James Easterbrook, of the Royal Fusiliers, at
St Mary's Church, Chester.  The address given for the reply was "118,
Whitefriars, Chester"--an address which I took early opportunity of
scribbling upon my shirt-cuff.

Suddenly Doris, who had taken the card from my hand, raised it to her
nostrils and sniffed at it.  "Why," she said, "it is scented.  I never
saw an English wedding card scented before."  And she sniffed again and
handed the card to me.  I raised it to my nostrils and decided that the
odour was either that of lemon-scented verbena or the old-fashioned
stag-leaved geranium.  The scent was fast disappearing, and it was
evident, from the age of the card, that it must have been very pungent
when fresh.

Small things mean much in our profession, and it struck me at once that
Doris's discovery might be decidedly important.  Here we had a perfectly
innocent-looking invitation to a wedding in England, printed in quite
the ordinary English style, and, judging from the type employed,
evidently the work of an English printer.  Yet the card, found by chance
in the house of a foreign suspect, showed a variation from English
social customs which Doris, womanlike, had instantly detected.  The fact
of the card being scented, had I been alone, would certainly not have
struck me as being of any peculiar significance; very few men, I am
certain, would have given it a second thought.  Yet the trivial
circumstance was to be the means of leading us finally towards our goal.

"Are you sure they never perfume wedding cards in England?"

I asked Doris.

"Absolutely," she replied.  "I have never heard of such a thing.  The
card is of excellent quality, and, judging from the fact that the
bridegroom is a military man, the parties must be of fairly good social
circles, in which any departure from the accepted custom in such things
would be regarded as `bad form.'"

"Well," I thought, "it may be important."  At the same time I realised
that the card might have lain in contact with a scented handkerchief,
and thus absorbed part of the odour.  As against this was the fact that
the scent was not a common one.  I decided in my own mind that the
matter might be worth looking into, and, when the old custodian's back
was turned, took the liberty of slipping the card into my pocket.

Soon after, having learnt all I could about Cauvin and his abode, we
left the Villa des Fleurs, and, giving the old woman a handsome tip,
returned to Mentone.  The same evening I left for Marseilles, Doris and
her mother remaining behind for a day or two before returning to
England.

Somehow I could not dismiss the subject of the perfume from my mind;
why, I cannot exactly tell, for I could not see precisely the bearing of
the card on the problem I had to solve.  Was the perfume verbena or
scented geranium, and had the card any special significance?

Next day, in Marseilles, I entered the shop of one of the leading
perfumers in the Cannebiere, and asked the young lady assistant whether
she could identify the perfume for me.

"Certainly, monsieur," she said without hesitation; "that is geranium."

"Are you quite sure," I asked, "that it is not verbena?"

"Monsieur shall decide for himself," was the ready reply, and the girl
at once fetched samples of both perfumes.  A single test was enough to
show that she was correct.  And then, recognising the purpose of the
card, though she could not speak English, she practically duplicated
Doris's remark.  "Is it not unusual, monsieur, to scent a wedding card?"

That set me thinking furiously.  It was quite possible that Doris might
have made a mistake about a point of social etiquette.  But here was a
young Frenchwoman corroborating her in quite a dramatic fashion.

"It is unusual; I suppose they are peculiar people," I replied as I
left.

It is one of the penalties of contra-espionage work that one becomes
almost morbidly interested in the seemingly trivial.  One of the first
lessons to be learnt is that nothing is so small that it can be safely
neglected.  There were, it was obvious, many ways by which the card
might have become accidentally impregnated with the perfume.  But my
intuitive suspicions grew ever stronger, and at last I found myself
convinced that there was "something in it."

In one particular, at any rate, the card was of first-rate importance.
Try as we would, we had failed entirely to connect Cauvin with anyone in
England.  We were morally certain that he must be receiving messages and
money in some subterranean way, but it was certainly not through the
post, and up to the present we had failed to find, among his big list of
acquaintances and friends, anyone whom we could reasonably suspect of
being in touch with the Hidden Hand across the Straits of Dover.  But
there were many possible channels of communication through neutral
countries, and obviously we could not stop them all.

Now, with the aid of the wedding card, it seemed possible, always
assuming the card to be genuine, that I might be able to locate one
person at least in England who was upon extremely friendly terms with
our wealthy suspect.  That chance, at any rate, whether the perfume
meant anything or not, I was resolved not to miss.

Treachery was rife everywhere.  In Russia, in Italy, in Roumania, in
Greece, and in other countries, men of apparently impeccable reputation
were one after another being unmasked in their true characters of agents
of the enemy, and were paying the penalty of their perfidy.  In France
several first-class scandals of this kind had recently absorbed the
attention of the public.  That England had hitherto been comparatively
free from any of these _causes celebres_ was due, as I well knew, not to
the absence of culprits, but to the lazy British good nature, which,
coupled with the apathy of men in high places who had always laughed to
scorn the very idea of the German spy in England, refused to look
unpleasant facts in the face unless they became unduly obtrusive.  And
the picked men of the Hun spy bureau could be trusted not to make
themselves conspicuous!

The great Hun octopus does not advertise its presence.  It puts its
faith in the powerful god Mammon, always sure of finding willing
victims, and his chief disciple, Blackmail.  Some day or other I may be
able to tell the story in more detail; it will certainly be of absorbing
interest.  At present, however, it must give way to the exigencies of
the war situation.  The Germans would be only too glad to learn just how
much we know; the British public would probably explode into a blaze of
indignation if they once fully realised the supine attitude of their
rulers to the ever-present and ever-growing menace of the German spy in
their midst.

CHAPTER SIX.

IN THE "PERSONAL" COLUMN.

I had a good deal to do before I could leave for England.

From Marseilles I left for St Etienne and Chartres, in both of which
towns Jules Cauvin had been known in pre-war days.  But little
additional information which was of value could I pick up, though I was
specially struck by the fact that all who knew him laughed at the bare
idea of his having blossomed out into a motor expert.  They all seemed
equally convinced on this point.  One man even ventured the suggestion
that, if Cauvin was indeed making huge sums of money from a motor
invention, he must have stolen the idea from someone else.

"And, believe me, monsieur," ejaculated the voluble Frenchman, "he would
not be above doing so.  Jules Cauvin an inventor!  Phew! he is too lazy;
he never did any work if he could help it."  However, as I was tolerably
sure in my own mind that Cauvin was being handsomely paid for services
of quite another kind, this did not help me much.

At length, after a journey of a week, during which time I spent only one
night in bed, I found myself late one afternoon back in Paris, chatting
with my colleagues, Madame Gabrielle Soyez and Henri Aubert, in the
former's cosy little flat _au troisieme_, in the Boulevard Pereire.  To
both I gave certain very definite instructions.  To the elegant little
Frenchwoman I added:

"You will proceed to the Grosvenor Hotel in London, and from there will
keep the surveillance I have indicated.  Remain there until you hear
from me.  Report progress frequently--at least every other day--in the
personal column of _The Times_."

I could scarcely refrain from smiling as I turned from the vivacious
Frenchwoman--a Parisian in every detail of her _chic_ appearance--to
Henri Aubert, who was to be our colleague in the undertaking we had in
hand.  Aubert was a sad-faced, rather melancholy looking middle-aged
man, with a face from which every shred of intelligence seemed to have
vanished.  He looked, indeed, exactly like one of those middle-class
nonentities, colourless and featureless, who, by the mysterious workings
of the mind of the great god Democracy, manage to get themselves elected
as municipal councillors, or by superhuman endeavour rise to the
position of advocate--and never do any good.  But behind his unpromising
exterior, which, in fact, was one of his chief assets, since it
practically freed him from any possibility of suspicion, was a keen
intelligence, trained in every detail of our craft, a patience that knew
no wearying on the trail, and a judgment which closed like a steel trap
on the essential factor in a complicated situation, and, once having
secured a hold, never let go.  I knew him well and esteemed him highly,
and he possessed the entire trust of the astute Armand Hecq, a trust
difficult to win, but, once won, fully and freely given.

To Aubert I explained the situation as fully as I could, and, though I
knew him to be a model of circumspection, I ventured on a hint of the
extreme care and discretion necessary in the delicate affair if we were
to succeed in tracing the source of Cauvin's mysterious rise to sudden
wealth.  He listened to me with a ghost of a smile on his thin lips, but
he was evidently piqued.

"Perhaps, Monsieur Sant, someone has been telling you I am a confirmed
babbler?" he said dryly; and I laughed; the idea of Aubert "babbling"
had its humorous aspect.

"I think we understand each other, Monsieur Aubert," I said.  "I don't
mean to cast any reflections on your discretion.  But you know the
people we have to deal with."

"Quite well, monsieur," replied Aubert, with a real smile this time.
"We have a difficult job before us.  They have a dangerous gang over in
England just now.  Pierre Gartin was murdered there only last week--shot
in a street row unquestionably got up for the occasion.  Of course the
assassin escaped in the crowd.  I think we had better take our
revolvers."  He spoke as coolly as though his revolver were his
umbrella.

I was startled.  Pierre Gartin was one of the most capable men we had,
and I knew he had been engaged on a piece of work very similar to that
which we had in hand.  In my absence I had not heard of his death.

"No, I had not heard," I replied.  "But I agree with you that our
revolvers might be useful."

Aubert's news told me that our Hun antagonists must have some very big
plan in hand.  Even the most desperate of spies draws the line at
murder, unless he finds himself in an impasse with no other way out.
This is not, of course, from any special reluctance to taking the life
of an enemy, but simply as a matter of self-preservation.  For we are so
peculiarly constituted that we tolerate calmly the work of pestiferous
agents whose activities are a greater peril to the community than a
dozen murders would be, while the killing of a single man brings a
hornets' nest about the murderer's ears.  I knew therefore, that since
the Huns had gone so far as to "remove" Gartin, they must be engaged in
work of supreme importance, and must have been quite aware that he was
hot on their trail.  Truly we had an interesting prospect before us.
But we were all tolerably well used to danger, and I do not think it
affected any of us.

"Only last night," said Aubert, "Cauvin entertained Bonnier, of the
Admiralty, and no doubt he learned something from him.  I have found out
that he has been lending Bonnier a good deal of money.  Bonnier has
recently got mixed up with a fast set, and he has been spending a great
deal more money than his income warrants.  When people of that kind
begin to consort with rogues of Cauvin's stamp it usually means only one
thing."

"No doubt that is true enough," I replied; "but for the present we must
take even the risk of leaving Bonnier alone.  I want absolute evidence
that Cauvin's money comes from Germany, even though he actually gets it
from a secret source in England.  It is not enough for me to prove
either that Bonnier is selling secrets or that Cauvin is buying them.  I
want to prove that Cauvin's money is German, and I am going to do it.
Bonnier can wait; if we get Cauvin we are tolerably sure to obtain
sufficient evidence to lay Bonnier by the heels at any time.  In fact,
we can remove him quietly as soon as Cauvin is out of the way.  I shall
leave for England to-morrow."

This I did, and twenty-four hours later I was in London.  I decided
first to investigate Cauvin's supposed motor invention, and made my way
to the office of a well-known patent agent in Chancery Lane.  He had
done some business before for me and greeted me warmly.  I knew him so
thoroughly that I did not hesitate to tell him exactly what I was after.

"But, my dear Sant," he said, "if this supposed invention is being kept
as a secret to stagger the motoring world, it is not likely to have been
patented yet by either Cauvin or anyone else.  Depend upon it, if there
is anything in it, it is being manufactured secretly, and will not be
patented until it is absolutely ready for the market.  To patent it now
would simply be setting every motor expert in the country at work on
similar lines.  You know the patent lists are watched with the keenest
scrutiny.  My clerk is looking into the matter, and we shall soon know
whether Cauvin has patented anything."

This was a surprise for me.  I could not, of course, however much I
might suspect him, absolutely rule out of my calculations the
possibility that even Cauvin might have hit upon some lucky idea, as so
many inventors have done, without knowing much of the technicalities of
the subject.  I did not forget that the safety-pin was the invention of
a lazy workman.  And I knew that if I took any active steps against
Cauvin and made a mistake--if by some miraculous chance his sudden
wealth was honestly acquired--the consequences would be serious.

"Well," I said, when we had been assured that no patent of any kind had
been taken out by Cauvin, "what am I to do?  I can't go to every big
motor engineer in England and ask him if he is manufacturing a secret
device invented by Jules Cauvin."

My friend thought for a few moments.  "I think you had better see L--,"
he said at last.  "If there is anything big in hand some kind of whisper
of it is sure to have got about, and he would be the first to hear.  I
will telephone him at once; we shall catch him in his office on the
Viaduct."

A few minutes later we were in Holborn in L--'s office; he was one of
the magnates of the motoring world.  I explained the position.

"You can make your mind easy on that point," he said emphatically.
"There is nothing going in the trade to-day big enough to produce the
amount of money your man is evidently receiving.  If there were, I must
have heard of it; it could not be kept secret.  You remember the Marx
carburettor?  Well, we knew for six months that it was coming, though
every effort was made to keep it secret.  What we did not know was the
exact secret; but you know how it took the market by storm."

This, even though it were only negative evidence, seemed to establish
conclusively the fact that Cauvin's money, whatever might be its source,
was not derived from the motor trade.  I made up my mind that this much
at least was certain.

Next day I travelled down to old-world Chester, where I very speedily
discovered that there was in Whitefriars no house numbered 118, and no
trace of any person named Wheatley, while the aged vicar of St Mary's
knew nothing of the marriage of "Captain James Easterbrook."

Everything was fictitious--everything, that is, except the
silver-printed wedding card and the clinging perfume of stag-leaved
geranium.

What did the bogus card indicate?  Why had Jules Cauvin's unknown
correspondent gone to the trouble of having it printed?  And why, in
defiance of all social custom, had it been scented with such a perfume
as that of the stag-leaved geranium?  I felt tolerably sure that here
lay the key of the mystery, and that when I laid my hand on the sender
of that mysterious card I should be very near indeed to the knowledge of
the real source of the strange sequence of events which had raised the
good-for-nothing son of an obscure French postman to a dazzling position
in the world of society.

Such was the problem I had to solve.  And the key to it was just one
bogus wedding card impregnated with the slowly dying odour of geranium.
I cursed my luck as I reflected on the magnitude of the issues at stake
and the paucity of the tools with which I had to work.  For if "Captain
James Easterbrook" was unknown in Chester, the home of his supposed
bride, what was my chance of penetrating his disguise?  Yet, somehow or
other, we must succeed.  That Cauvin was receiving money from England I
was absolutely convinced, and I was determined to take this chance--the
best we had had--of locating the real men behind the Hidden Hand in
England.

Next day I left Chester by a very early train for London.  When we
reached Rugby I bought a copy of _The Times_, and the first thing that
caught my eye was a cryptically worded message at the head of the
personal column.  It conveyed to me the startling news that Madame
Gabrielle had been recognised by some alien agent of whom she was highly
suspicious, had left the Grosvenor Hotel in her alarm, and had returned
to Paris!

CHAPTER SEVEN.

THE ELUSIVE VAN ROSEN.

Evidently something very serious had happened.

My first impulse was to hasten to the Grosvenor Hotel, engage a room
there, and try to discover something of the cause which had brought
about Madame Gabrielle's sudden flight.  Perhaps my anxiety for her
safety operated more powerfully than I ought to have allowed.  In our
business personalities are nothing; it is the end that counts.

A moment's reflection showed me that in taking this course I should
simply be playing into the enemy's hands.  I was too well known.  I
hoped that my presence in England was not suspected by the German
agents, and if I ventured to stay at the Grosvenor they would certainly
very soon have me under close observation.

By using the official telephone between London and Paris I managed to
get into communication with Madame Gabrielle at her flat in the
Boulevard Pereire, and soon learnt the reason for her flight.  Van Rosen
had discovered her, and was watching her closely.

Here, indeed, was an antagonist worthy of my steel!  I had long known--
and so far as his abilities went, had respected--van Rosen as one of the
cleverest agents of the Koniggratzer-strasse.  He was able to pose as an
Englishman--a rare accomplishment in a German--for he had been educated
at Haileybury, and had been in England off and on since his youth.  He
was now living in a north-western suburb, where he posed as Mr George
Huggon-Rose, a solicitor who had retired from practice.  Only British
apathy made this possible.  A moment's investigation would have shown
that the man could not have been what he pretended, for no such retired
solicitor as Mr George Huggon-Rose was known to the Law Society.

As a matter of fact, it was through this very slip on his part that I
had "spotted" van Rosen.  We had suddenly lost sight of him a year or
two before, and try as we would--for we knew that wherever he might be
he would be dangerous--we could not locate him.  The accident which led
to his discovery was curious.  I had been spending a few days in North
London, and one morning stopped at the railway bookstall to buy a paper.
As I approached the stall a tall, gentlemanly looking man, who had been
chatting with the clerk, turned away and entered the train.  Something
about him struck me as strangely familiar.

"Who is that gentleman?"  I asked the man at the stall.

"Oh," he replied, "that's Mr Huggon-Rose.  He used to be a solicitor in
the City, but he retired and has been living here for a year or two."

But I was not quite satisfied; some odd memory, in which I felt sure Mr
Huggon-Rose was concerned, haunted me all the way to town, and I could
not shake it off.  I had only seen van Rosen once, though I had had a
good deal of experience, and it was not surprising that I failed to
recognise him.  When I got up to town I consulted the _Law List_, but
could find no trace of Mr Huggon-Rose.

Then I became more suspicious, and before many days were over I had
succeeded in definitely identifying Mr Huggon-Rose with one of the
Kaiser's cleverest spies.  Thus the mystery of van Rosen's disappearance
was solved by his own slip.  If, when I looked up the _Law List_, I had
found Mr Huggon-Rose's name and address duly set out, I should probably
have thought I had been deceived by some chance resemblance and wasted
no more time on the matter.  How true it is that trifles make the sum of
life!

The position now was plainly serious: van Rosen's presence in London
boded no good.  The man was as unscrupulous as he was clever.  The
British contra-espionage department knew him well and had been greatly
chagrined at losing sight of him.  Afterwards, in consequence of my
report to Hecq, he had been kept under close observation; but we had
never been able to secure sufficient proof to justify his arrest, strong
though our suspicions were.  He had evidently been walking very warily
since the outbreak of war.  Unfortunately he had adopted that easiest of
all cloaks of the German spy, and had become a naturalised Englishman
just before war broke out.  But the adage "Once a German always a
German" applied with special force to van Rosen.

After speaking with Madame Gabrielle I had a long chat with Hecq over
the private wire, and together we mapped out a pretty comprehensive plan
of campaign, in which both Aubert and Madame Gabrielle had very definite
parts to play.

Then the mysterious scented wedding card claimed my full attention, for
I was determined to sift its secret to the bottom.  First, I paid a
visit to Somerset House, where I very thoroughly searched the records of
recent marriages.  These showed me that no marriage had taken place
between persons named Wheatley and Easterbrook.  A certain Agnes
Wheatley had been born in June, 1894, at Mina Road, Old Kent Road, in
the parish of St George the Martyr, Southwark, and there were records
of two James Easterbrooks.  One was James Stanley Easterbrook, born in
Lord Street, Southport, in 1881; the other, James Henry Charlton
Easterbrook, had first seen the light of day in the village of
Forteviot, Perthshire, in 1870.  The _Army List_, of course, failed to
show any Captain James Easterbrook, of the Royal Fusiliers.

All this did not carry me much farther.  The father of the Southport
Easterbrook was apparently a prosperous Blackburn tradesman; but that of
the man born in Scotland was vaguely set down as of "no occupation," a
curious entry for a Scottish village, where practically everybody would
be likely to live by the labour of his hands, and where one would hardly
expect to find persons of leisured independence.  The fact worried me.
But an inquiry at Forteviot showed that there had been no Easterbrooks
in the village for many years, and no one seemed to recollect anything
about them.

In order to conceal myself from the astute van Rosen, I had taken rooms
in a cheap boarding-house, full of old ladies, in Guilford Street,
Bloomsbury, and, equipped with a silver discharge badge and a set of
"faked" Army papers, posed as an invalided soldier recovering his health
before taking up work.  I was thus able to disarm the inquisitive prying
of my fellow-boarders, and I am afraid I gave them some highly
remarkable "information" about the war and my share in it!  If one is
engaged in spying or contra-espionage work one must be ever ready to
combat silly suspicions that give rise to endless gossip and to evade
unfriendly and malicious comment.

The enigma of the wedding card worried me incessantly.  That the
prosperous Jules Cauvin was one of the puppets of Potsdam, and also that
he had betrayed France, I felt morally convinced.  Hecq, indeed, held
documentary evidence of Cauvin's friendship with the Austrian
millionaire spy, Herr Jellinck.  I knew, almost with certainty, that the
perfumed wedding card was intended to convey a message of some kind,
since in every particular it was clearly shown to be a bogus document.
Yet without more direct evidence Cauvin, had we ventured to arrest him,
must have slipped out of the clutches of the law.  For, after all, mere
friendship or acquaintance with a spy, however suspicious, does not
prove the guilt of espionage.

Inquiries made by the British Special Branch soon showed that none of
the Easterbrooks in the British Army could by any possibility be
connected with the "Captain Easterbrook" of the wedding card.

Within a week I established the fact that Agnes Wheatley had died before
she reached the age of ten years.  Therefore, she could not have been
the mysterious bride to whose "wedding" Jules Cauvin and his wife had
been invited.  I was thus thrown back on the two Easterbrooks, and for
the next few days, if I may use the term, I breakfasted, lunched, and
dined on Easterbrooks!  And helping in my quest were some of the
smartest men of the British Special Branch.

Six weeks went by--weeks of feverish activity and incessant patient
investigation.  That mysterious wedding card, with its pungent odour of
stag-leaved geranium, hypnotised me, and I could think of nothing else.
And everything began to seem so hopeless that even the Scotland Yard
men, most unrelenting and unwearying searchers-out of hidden mysteries,
began to get depressed and to fancy they were hopelessly beaten.

Van Rosen, of course, was under constant surveillance.  Whether he
suspected it or not I do not know, but for the time being he seemed to
have entirely abandoned his usual business.  He went about quite openly,
and I often wondered whether he was tacitly defying us.  Probably his
work was so far advanced that he could afford to wait, and hoped to
disarm suspicion by the very openness of everything he did.  Had there
been any real necessity we could, of course, have arrested him on some
charge or another, but we still hoped that by giving him plenty of
latitude we should sooner or later stumble on some valuable information.

CHAPTER EIGHT.

"ONE OF THE NATURALISED."

The weeks slipped by.

We seemed no nearer gaining our object, and I found myself wondering at
times whether, indeed, I was not engaged on a wild-goose chase.  Poring
over everything that was known of Jules Cauvin, I sometimes found myself
ridiculing my own suspicions.  Still, that mysterious card forced itself
on my attention.  Cauvin's friendship with Jellinck, his known
association with Miassoyedeff, shot as a spy in Russia, his sudden and
inexplicable wealth, all convinced me in the long run that there was a
deep secret to be fathomed.  I had the chain of evidence nearly
complete, but one link was missing--the source of Cauvin's wealth and
the identity of the mysterious individual from whom he drew unstinted
funds.

Three weeks more passed.  The Special Branch at Scotland Yard was
becoming disheartened.  I myself was losing hope, and Hecq was obviously
growing restive.  Then the tide turned.  One of the Special Branch,
apparently by the merest accident, discovered the printer of the bogus
card.

This was a discovery indeed!  I hastened to interview the printer--the
proprietor of a small jobbing business named James in the Uxbridge Road.

"The cards," he told me, "were ordered by Mr Easterbrook for the
wedding of his son, the Captain Easterbrook referred to.  Mr
Easterbrook lives in Lancaster Gate," and, referring to his order book,
he gave me the address, for which I thanked him.

"Did you perfume the cards before you printed them?"  I asked him
carelessly.  I had kept the most important question till the last.

"Perfume them!" he snorted, glaring at me through his spectacles.  "Why,
of course not--we don't scent invitation cards to weddings!"

I knew that well, but I was glad to get the fact verified.  And now for
Mr Easterbrook and the captain!  I was in high spirits, for I felt that
at length I was getting near the heart of the mystery.

Going direct to Lancaster Gate, I soon found the Easterbrooks' house, a
large, handsome building overlooking Hyde Park.  A few local inquiries
soon told me all I wanted to know, and shortly after I was conveying my
news to Hecq over the Paris telephone.  For once the phlegmatic little
man was shaken out of his habitual reserve, and his voice, when he had
heard my news, fairly trembled with excitement.  At last we were at
close grips with our mysterious foe.

Next day, Madame Gabrielle, whom I sent for again, and Aubert were
installed in rooms in an obscure house in Bayswater.  I spent the
evening with them, and together we evolved a plan of operations which, I
confess, required considerable "bounce"--I do not like the expression
"daring" when it has to be applied to one's self.

By this time I had cut myself adrift from our excellent colleagues of
the Special Branch, fearing lest van Rosen and his friends might get on
my track.  So far, apparently, he had not located me, for, though I kept
the sharpest possible look out, assisted by a clever detective who
habitually assumed different disguises for the purpose, I could find no
evidence whatever that I was being "shadowed."  Madame Gabrielle,
Aubert, and myself were also working apart, though I was directing the
general plan of operations.

Following up the trail I had struck in the Uxbridge Road, I soon secured
some astounding facts regarding Mr Essendine Easterbrook, of Lancaster
Gate.  He was actually a native of Frankfort, who, after a brief but
amazingly successful career in the City as a promoter of rubber
companies, had amassed a big fortune and retired from the game of
finance.  He had become naturalised in 1909, and, profiting by the
Briton's amazing indulgence to aliens of every kind, had changed his
name from Essendine Wilhelm Estbruck to Essendine William Easterbrook.
Very few people, I found out, had any idea of his real origin and of his
German parentage and nationality.

Now Mr "Easterbrook" had no son.  He had, however, an English wife, and
his wealth had won for them a position in London Society.  They had
frequently, before the war, entertained at their handsome house the wily
director of propaganda, von Kuhlmann, who was then living in London, and
also a certain Max Garlick.  But, try as I would, I completely failed to
establish any sort of connection between the Easterbrooks and Mr
Huggon-Rose.

The name of Garlick, however, told me a lot.  Garlick had been the
German Secret Police Councillor in France, for the Departments of the
Nord, the Pas de Calais, the Somme, and the Ardennes.  He was an
ex-naval lieutenant, and two years before the war broke out was
appointed to the arduous, but lucrative, office of Polizeirath for
London, establishing his office nearly opposite the Army and Navy Stores
in Victoria Street, Westminster.  This _mouchard_, in order to disguise
his true occupation, was in the habit of putting in a few hours' work
daily at a desk in the London offices of the Hamburg-Amerika line in
Cockspur Street.  That Essendine Easterbrook, the "father" of the
non-existent "captain," had been the friend of Max Garlick was quite
sufficient to show his connection with the enemy, for Garlick had been
the head of the "actives" in England.

We then set to work to obtain more inside evidence.  Aubert, on my
instructions, watched carefully, and soon made an opportunity of getting
into the confidence of Mrs Easterbrook's English maid, a young woman
named Dean.  He found out without much trouble that she was not greatly
attached to her mistress, who, in spite of her gushing manners in
Society, was harsh and domineering towards those in her employ, and was
totally incapable of winning either respect or affection.

Dean had been engaged from a local registry office in the neighbourhood,
a fact which materially facilitated our plans.

I had a long interview with the young woman.  She had a sweetheart
serving in the Army, who had seen a good deal of German methods and had
told the girl enough of the sufferings of the conquered French and
Belgian populations to fill her with an intense hatred of Germans and
Everything German.  Directly I informed her that she had been working
for a naturalised German her indignation knew no bounds, and she
willingly gave me a lot of valuable information.  She declared,
moreover, that she would not remain in the place another day.  This,
too, was exactly what was wanted.  I impressed upon her the necessity of
keeping absolutely silent on the subject of her employers' real
character, and set about the task of getting her place filled with a
nominee of my own.

This, of course, could be no other than the resourceful Madame
Gabrielle, who, laying aside, as she often did, her wedding ring,
registered her name at the registry office as a French maid.  A handsome
_douceur_ to the excellent registry keeper and some highly satisfactory
references, carefully prepared for the occasion, accomplished what we
wanted, and in the course of a week I had the satisfaction of knowing
that the Easterbrook household was under the close surveillance of one
of my smartest assistants, who posed as Mademoiselle Darbour, and was
quite certain to miss no opportunity that might present itself to her.

We soon obtained further information about Mr Easterbrook.  He was
evidently a wealthy man in reality, as well as appearance, owning, in
addition to the Lancaster Gate house, a big estate in Derbyshire, a
shooting-box in the Highlands, and a Villa at Cabbe Roquebrune, above
Cap Martin, not far from Cauvin's Villa des Fleurs at Mentone.
Moreover, he dabbled in yachting after a fashion, more, I suspected, for
purposes of social advertisement than from any love of a sport which
makes but a slight appeal to Germans.

We were, of course, living on the edge of a powder magazine, and the
position of Madame Gabrielle, alone in the very camp of the enemy, was
especially perilous.  At any moment one or all of us might be recognised
by the alert agents of van Rosen, and I was beginning to know enough of
the true position of Mr Easterbrook to realise that the desperate men
with whom we had to deal would stick at nothing to rid themselves of
danger if once they divined our identity and purpose.  For Madame
Gabrielle I was especially anxious, and more than once I debated
seriously whether I was justified in allowing a woman to run so grave a
risk.  For Aubert and myself, of course, such a question naturally did
not arise; risk was a part of our profession, and we accepted it just as
we accepted a wet day.  However, we were playing for a great stake, and
I finally decided to play the game out to a finish.

A month passed.  The reports I received from Madame Gabrielle, working
inside the house, and from the painstaking Aubert, who let nothing
outside escape him, were full of interest.

Mr Easterbrook, formerly Herr Essendine Estbruck, native of Frankfort,
remained entirely unsuspicious that he was under the eye of one of the
keenest secret agents in Europe.  It was important that he should remain
in ignorance, and I prepared a little plan which I felt sure would be so
completely reassuring to him that it would throw him completely off his
guard, and yet put him in such a position that he would find it almost
impossible to resist the temptation, carefully arranged by us, to betray
the country of his adoption.

It so happened that an important post had become vacant in a certain
Government department dealing with a large number of confidential plans.
I found out from Madame Gabrielle that, as a matter of fact,
Easterbrook had for a long time been working strenuously to secure a
Government appointment--honorary, of course, since money was no object
to him, except as a means to an end.  I have no doubt whatever that his
motives were twofold.  The first was, by securing official recognition,
to remove any suspicion that might cling to him in consequence of his
enemy origin; the second, I have just as little doubt, was to secure
better opportunities of playing the spy.  I made up my mind to oblige
him in both particulars, but to arrange the _denouement_ myself.

I went to the Minister concerned, and revealed my plan.  When I had
fully explained to him what we knew and how much we suspected he
realised the gravity of the situation, and, though my request was
entirely irregular, he consented to what I asked.

A week later a paragraph in the London papers announced that Mr
Essendine Easterbrook had been appointed a controller in a certain
department of the Admiralty.  There were a few cavillings in some
quarters, on account of Easterbrook's origin, but to the general public
the position did not seem to be one of great importance, and little
notice was taken of the appointment.  As a matter of fact the position
was a bogus one, created for the occasion, and everything connected with
it had been arranged by the astute Special Branch with the sole design
of entrapping Mr Essendine Easterbrook and the intermediary, whoever it
might be, between the German agents in England and Jules Cauvin.  For
the wedding card had proved beyond doubt that Easterbrook and Cauvin
were in close communication.

CHAPTER NINE.

THE SECRET OF THE PERFUME.

Mr Easterbrook soon found himself comfortably ensconced in a large
room, and surrounded by a staff, every single member of which, though he
little suspected it, was in the direct employ of the Special Branch.
Few suspects have ever been subjected to such microscopic scrutiny.  He
literally could not make a single movement unobserved.  He was
constantly shadowed in and out of his office by agents who were relieved
every few hours; inside his house Madame Gabrielle was incessantly on
the watch.  And in the meantime we prepared for him the trap which
proved his undoing.

One day Mr Easterbrook found awaiting his attention a number of copies
of an "urgent" and "strictly confidential" memorandum which gave in
elaborate detail the plan of a naval operation which for sheer
dare-devilry was enough to take one's breath away.  Needless to say, it
was "spoof" from beginning to end.  But it was spoof so thoroughly
plausible in its conception, and so artistically worked out in its
wealth of detail, that it might well have deceived someone far better
versed than Herr Estbruck in naval matters.  I had the privilege of
going over it with the distinguished naval officers who drew it up, and
I can hear to-day the roars of laughter with which it was received by
the company of experts gathered to listen to the elaborate joke.  Of
course the men who really knew detected the imposture at once; to the
novice the plan looked like the details of a gigantic attack on one of
Germany's strongest naval bases.

Now we calculated deliberately that Easterbrook, getting hold of the
bogus plan, would be unable to resist the temptation to communicate it
to Germany.  To him, we knew, it must appear of stupendous importance.
It was too elaborate for him to attempt to memorise the details, and far
too long to give him a chance of copying it unobserved.  Moreover, we
decided to convince him, if possible, that he could purloin a copy
without risk.

Now with confidential documents of importance, every single copy must be
accounted for.  The printing is done under the closest supervision; the
exact number of sheets of paper required is issued; every official who
receives a copy signs for it and gets a receipt when he parts with it.
Mr Easterbrook had been well drilled in the routine.  We had made him
especially careful by inducing him on one occasion carelessly to sign
for four copies of a document when he only received three, and the
trouble we raised about the "missing" copy must have made him determined
to count his copies in future.  We relied on that to catch him and his
associates.

Early one morning a messenger laid upon Mr Easterbrook's desk _four_
copies of the naval plans.

"Please sign for three copies of Number 27162 A.B., Mr Easterbrook,"
said the lad, laying the book before him.

A keen-eyed watcher saw Mr Easterbrook glance at the heading of the
document which lay before him.  Clever though he was, he was unable to
repress a start of astonishment as the amazing title, carefully designed
for the occasion, caught his eye.  A moment later he had recovered
himself, counted his copies of the paper, and, glancing at the book,
signed for _three_.  The bait was swallowed!

I must now hark back to Madame Gabrielle to make clear the chain of
events which followed.  The sprightly Frenchwoman soon found out that
beneath an unprepossessing exterior her employer concealed an extremely
amorous disposition.  Exerting the full power of her fascinating
personality, she soon began to exercise a considerable influence over
the financier, and was able at length to solve the problem of the
mysterious perfume.

A few hours after the secret "plans" had been laid before him,
Easterbrook made a clandestine arrangement to dine with Madame Gabrielle
at a restaurant in Soho the next evening.

"I have to go out of town to-night," he said.  "I don't want to write,
but if you get by to-morrow's post a plain sheet of paper scented with
geranium I shall be there.  If it is scented with violet you will know I
have been detained and cannot come."

So the secret was out at last!  The wedding card had been a signal to
Cauvin that all was well.  Had it been scented with violet it would have
indicated danger.  As will be seen, we had little difficulty in guessing
the purpose of Easterbrook's absence from his house that night!

We calculated that, finding he had been debited with three copies of the
"plans," whereas he actually received four, Easterbrook would calmly
pocket one of them and return to the proper department the three for
which he had signed.  Events proved that we were right.  In the
afternoon, at the usual time, he left the office.  Three minutes later
we ascertained that the fourth copy of the "plans" was not in his desk.
He had taken it with him, and it was easy to guess his purpose.

From that moment his doom was sealed.  We could have arrested him at
once, of course, but we wanted to know by what means those plans were to
be dispatched to Germany.  If we could only find that out one finger of
the Hidden Hand would assuredly be lopped off for good.

On leaving the office Easterbrook made for a public telephone office,
where, as it happened, three boxes stood side by side.  As he entered
the one, an agent of the Special Branch entered the one farthest from
him.  The boxes were of the threepence-in-the-slot pattern, and the
trifling delay caused by dropping in the three pennies gave the
detective his opportunity.  Ringing up the operator at the Exchange, he
demanded, in the name of the police, that Easterbrook's conversation
should be "tapped."  The operator promptly "plugged" him on to the line
Easterbrook was using, so that he was able to listen, quite unknown to
Easterbrook, to the conversation which followed.

"Is that 7257 North?"  Easterbrook began.  "I want to speak to Mr
Huggon-Rose," he went on.  "That you, Rose?  This is Easterbrook.  Will
you come down to Piccadilly and have some dinner with me?  I am just
arranging a yachting trip, and perhaps you would like to make one of the
party.  All right.  Be at Scott's at seven o'clock.  Good-bye."  And he
rang off.

Seven o'clock found Easterbrook and Huggon-Rose dining comfortably at
Scott's.  Four men of the Special Branch, immaculately attired and
apparently mere men-about-town, were seated at different tables near
them.  Easterbrook and his guest talked yachting ostentatiously, and
many maps and papers were handed backward and forward.  _One_ of these,
the lynx-eyed watchers noted, passed from Easterbrook to Huggon-Rose
_and was not returned_.  It was the confidential paper!  Another link in
our chain had been forged!

At half-past ten the two conspirators rose to leave.  At the door of the
restaurant they brushed past a man in seafaring dress, quite obviously a
Dutch sailor, and, swiftly though it was done, one of our watchers saw a
folded paper slip from Huggon-Rose's hand into that of the Dutchman.  He
made off at once, closely shadowed by two of our men, while Easterbrook
and Huggon-Rose walked away together, evidently looking for a taxicab,
none too numerous at that hour.

Just as a cab drew up to the kerb I arrived on the scene.  I had been
kept closely informed of what was going on and had been waiting in a
neighbouring restaurant in order to be present at the arrest of the two
plotters.  Incautiously I approached too near, and in the light of a
street-lamp van Rosen caught sight of me.  He recognised me instantly.
With a snarl of rage he turned on me, and his hand shot to his
hip-pocket.  Then he recovered his self-possession and entered the taxi
with Easterbrook.  No doubt he reflected that a shot at me would not
help him, and, it should be noted, neither man had any incriminating
document on him.  The "plans" were in possession of the Dutch sailor,
and until they were secured we had to hold our hands.  But one quarry
was safe now.

The taxi soon deposited the two men at Easterbrook's house, which was
immediately closely surrounded.  Half an hour later Madame Gabrielle,
hatless and showing every sign of a struggle, slipped from a side door.

Breathlessly she explained that van Rosen, catching sight of her as he
was going to his room on the first floor, had recognised her at once and
had attacked her furiously.  Why he did not shoot her I never could
understand.  Physically Madame Gabrielle was a match for him; she was a
superb gymnast and in hard training, whereas van Rosen had been leading
a dissipated life and was in thoroughly poor condition.  A brief
struggle had ended in Madame Gabrielle throwing him heavily by a simple
wrestling trick, and, knowing that she must get away at all cost, she
had rushed down the back stairway and got into the street.

A moment or two later a servant left the house and posted some letters
in the pillar-box a few yards away.  The letters were recovered later,
and one of them, a postcard, was found to be addressed to Jules Cauvin.
It was in a feminine handwriting, and bore neither the date nor the
address of the writer.  It read:

"My dear Jules,--Henri will return home to-morrow.  He has immensely
enjoyed his visit, and his health has greatly improved.

"Yours,

"Marie."

Innocent enough, but--_the card was perfumed with violets_!  Clearly
enough its purpose was to let Cauvin know that danger was in the air.

We were expecting every moment the news that the Dutch sailor had been
arrested with the incriminating documents in his possession.  That would
have been the signal for the arrest of Easterbrook and van Rosen.  But
the arrest was not to be made.

Far away to the east we heard the low boom of a gun.  Another and
another followed; then came the crash of high explosives, and we
realised that an air raid was in progress.  Nearer and nearer came the
sounds of guns and bombs.

Suddenly I picked up the drone of an aerial motor directly overhead, and
a few seconds later came an appalling crash that seemed to shake the
very earth.  I saw a red blaze flash out over Easterbrook's house, and
after that everything was a blank.

I came to my senses to find myself in Charing Cross Hospital.  And when
I feebly opened my eyes the first object to catch my sight was Armand
Hecq, seated at my bedside placidly reading a book.  Hearing my gasp of
astonishment, he turned to me.

"Ah, _mon cher_ Gerald, so you are awake at last," he said cheerily.
"How are you feeling?"

"Very shaky," I whispered.  "What has happened?  Ah, yes, I remember
now," I said, as a flood of recollections swept over me.  "Is it all
right?  Have you got van Rosen and Easterbrook?"

"Everything is quite satisfactory, my dear Gerald," replied Hecq.  "I
will tell you all about it when you are stronger."

But, weak though I was, I could not bear the suspense.  "Tell me at
once.  Monsieur Hecq, I beg of you, or I shall never rest."  And Hecq,
choosing the lesser of two evils, decided to unburden himself.

"Van Rosen and Easterbrook are both dead," he said.  "The bomb which
rendered you unconscious struck Easterbrook's house and killed them
both.  Mrs Easterbrook is terribly injured, but is alive, and will
probably recover.  Madame Gabrielle is quite safe, and Aubert, who was
watching near you, was sheltered from the explosion by a projecting wall
and was only badly shaken.  He telephoned me at once, and I fortunately
caught a train which was just leaving, and here I am.  You have been
unconscious for a day and a half."

"What about the Dutch sailor?"  I managed to gasp out in my
astonishment.

"Oh," replied Hecq, "we got him all right, with the plan in his
possession.  He has made a clean breast of everything.  The plans were
to have been photographed down to microscopic size and the films taken
over to Cauvin sewn into his clothing.  Two of my men are on their way
to arrest Cauvin at once."

But Cauvin proved too quick for us.  As the agents of the Surete
approached his house he must have recognised them and realised that the
game was up.  Directly they intimated to him that he was under arrest he
snatched a revolver from his pocket and shot himself before their eyes.
I have no doubt the result would have been the same if he had received
the violet-scented card, which now, with the bogus invitation to the
Easterbrook wedding, remains one of my cherished mementoes of one of the
most fascinating of the many mysteries I have helped to unravel.

Thus by the hands of the Huns themselves the public were spared an
astounding scandal, and the Allies were rid of three ingenious
scoundrels engaged in a clever and insidious campaign.  After
Easterbrook's death we were able to unravel the whole conspiracy.
Easterbrook and van Rosen were two of the fingers of the Hidden Hand in
England.  They operated by means of banking accounts in various names,
handling large sums placed freely at their disposal by other wealthy
naturalised "Britons," who proved in their own persons the truth of the
adage coined in 1914 by a naturalised Hun--"Once a German, always a
German."  Most of them were laid by the heels, and now, behind
barricades of barbed wire in remote parts of the country, have leisure
to repent the day when they matched their cunning against the skill of
the International Secret Service Bureau of the Allies.

CHAPTER TEN.

THE MYSTERY OF BLIND HEINRICH.

"Blind Heinrich!"

Without any conscious effort of memory on my part, these words flashed
suddenly into my mind, as, six weeks or so after the events just
related, I sat lazily in Armand Hecq's private room in the Boulevard des
Capucines, turning over our latest problem in my mind, while I waited
for the astute chief, who was busy investigating a report which had just
been brought in by one of his numerous financial clients--in other
words, by one of the numerous expert agents whom he kept constantly busy
up and down Europe, at the task of countering the villainous work of the
spy bureau in Berlin.

"I wonder whether he is mixed up in the affair," I mused; rapidly
working out a new train of thought to which the old scoundrel's name had
given rise.  So intent was I that I did not notice Hecq's entrance.  His
quick eye noticed my absorption.

"A penny for your thoughts, _mon cher_ Gerald," he laughed.

"Well," I said with a smile, "I was pretty far away, I admit.  The fact
is, I was wondering whether Blind Heinrich is taking any part in the
game?"

The director of the International Secret Service of the Allies raised
his brows and stared at me across the big, littered writing-table.
Behind him a tape machine was clicking out its message, just as it
should in a well-ordered financier's office.  He was evidently
surprised.

"By Jove!" he exclaimed in English, which he spoke to perfection.  "I
never thought of him!  My dear Gerald, old Heinrich is an extremely wily
bird; and if he is mixed up in this business we shall have all our work
cut out.  Remember how he wriggled out of our hands in the Gould affair,
when we thought we had him safely netted?"

The Gould affair!  I should think I did remember it!  I took a part in
tracing and arresting the spy, Frederick Adolphus Gould, who lived near
Chatham, and who, a few months before the war, was sent to prison for
five years for attempted espionage.  The case was a bad one.  For years
"Gould" had posed, like so many of his unscrupulous countrymen, as a
good, patriotic John Bull Englishman, unable to speak German, expressing
hatred of Germany and the Kaiser, and warning us that wax would come.
Yet, after his arrest, I had gone to Germany very much incognito to make
inquiries, and found that exceedingly patriotic "Englishman" was the son
of a certain Baron von S--, that he had been born in Berlin in 1851, had
fought in the Franco-German War, and had been awarded the customary Iron
Cross!

Now one of "Gould's" closest friends in England had been a certain
Norwegian named Heinrich Kristensten, a half-blind violinist who lived
at Hampstead.  Some strange facts came to light in the course of our
inquiries, but the afflicted musician forestalled us by very cleverly
coming forward and denouncing his whilom friend--not, however, before he
saw that Gould was quite hopelessly entangled in the net which had been
spread for him by the British Secret Service.  His action, of course,
was quite in accord with German practice.  Seeing that the game was up,
so far as Gould was concerned, he saved himself on the principle that
one loss was better than two.  His name had leaped spontaneously into my
mind in connection with the latest problem upon which we were engaged--
the mysterious manner in which, despite the rigid British censorship,
details of the damage done in London by the raiding Gothas were so
quickly and so accurately transmitted to Berlin.  That they were so
transmitted we knew, for the German papers promptly published them.  And
obviously, if severely censored matters of this kind were leaking out,
there was some channel of information open of which we were unaware.  We
had to find and close it.

Now, as is well known, every wireless message which passes from the
outer world to Berlin, or from Berlin to the outer world, is picked up
and decoded at our wireless stations.  The news was, we knew, not sent
by wireless.  Yet it was clear the Wilhelmstrasse got early information,
not only as to where the bombs were dropped, but the extent of the
damage done, both points on which they could not obtain the slightest
information from the English papers.  These details were published by
the German and Swiss papers, and, allowing for Berlin's invariable
exaggeration of its own prowess, they were remarkably full and accurate.
The task before me was to find out how the news was transmitted, and it
was one, I confess, which fairly bristled with difficulties.

"Heinrich, being a neutral, has lately been showing a great interest in
the welfare of blinded British soldiers," I remarked to Hecq.  "If he
were a friend of Gould's, why should he do this?"

"For some reason of his own," said Hecq, "possibly to avert suspicion.
We know pretty well that he was very deep in it with Gould and had
received money from him.  Perhaps you will recollect that he admitted
it, explaining that it was a loan, and indeed we found his I.O.U. in
Gould's desk, made out, no doubt, `to lend artistic verisimilitude to a
bald and otherwise unconvincing narrative,' as your Gilbert has it.  You
know he said his daughter had been ill, and that in consequence he was
short of money.  That was too weak; we knew well enough that Heinrich
made a good deal out of his fiddle, as his bank balance showed.  He was
not short of money at all, and I have not the least doubt that the
`loan' was for value received in the shape of information or assistance,
perhaps both."

"Yes, I remember now," I said, reflecting deeply.

Three weeks went by.  I was tired and run down, and decided to snatch a
fortnight with Doris in Worcestershire before embarking upon a task
which was likely to be arduous, if not actually dangerous.  Greatly
strengthened by my sojourn in delightful Worcestershire, I was back in
town, keenly interested in the work I had in hand.

One evening I had been down to Hertford, and was returning by the Great
Eastern Railway to Liverpool Street, when, just before ten o'clock, the
train pulled up abruptly at Stratford, all lights were instantly
extinguished, and I was swept into an excited throng of several hundreds
of refugees in the subway beneath the line.  There, amid a motley
gathering, largely composed of panic-stricken foreign Jews, I was
compelled to remain for over three hours, listening to the venomous
barking of the anti-aircraft guns and the occasional rending,
ear-splitting crash of a high explosive bomb.

It was the first time I had seen the alien under air-raid conditions,
though I had heard a good deal about him; and as I watched the cowardly
wretches my whole mind was revolted at the thought that a large
proportion of these quivering masses of jelly, for in their fright they
were little else, had been welcomed to British citizenship under the
imbecile naturalisation system.  No one blamed them for being
frightened: the Englishwomen and children of the working classes,
huddled in the shelters, were quite obviously frightened, and small
wonder.  But if they were frightened, they were brave, and they kept
their self-control even when the infernal racket overhead was at its
worst.  I had seldom seen a better proof of the essential superiority of
the Briton over the harpies who prey upon him, and as I watched I felt
proud that, cosmopolitan as I am, I had good English blood in my veins.

At ten o'clock next morning I went to Whitehall, where exact of all the
damage done by the Gothas was placed freely at my disposal.  From the
secret reports I made certain extracts for future use.

Five days later.

As I sat in my flat in Curzon Street, my man, Burton, brought in copies
of the _General Anzeiger fur Elberfeld-Barmen_, the Berlin _Borsen
Courier_, and the _Tageblatt_, all of which had been sent me by special
messenger from Whitehall.

I opened them, and in both the _General Anzeiger_ and the _Tageblatt_
were exultant articles on the success of the air raid upon the
metropolitan area a few nights before.  They were, of course, luridly
"written up," but they contained a great deal of perfectly accurate
information, as I knew by the secret reports shown to me directly after
the raid.

How could the enemy know?  Of course, the blazing accounts of the terror
and panic supposed to have been created in London could have been
written up anywhere.  But how was it that not only were the localities
in which the bombs had fallen accurately specified, but in several
instances details were given of the exact damage to certain buildings?
By no possibility could the latter information have been the result of
an effort of Teutonic imagination.  The enemy _knew_; proof of it was
there in cold print.  How did the news reach the Wilhelmstrasse so
quickly?

It was certainly not by wireless, for every message was picked up and
decoded by our own stations.  That the news had not passed through the
great German wireless stations of Norddeich, at the north of the Elbe,
or Nauen, near Berlin, was certain.  Here was a pretty problem set for
solution.

As I sat alone in my room that evening, having dined at my club and
returned to the enjoyment of slippers, a novel, and a good cigar, I
reflected on the task I had in hand.  I realised, of course, that my
suspicions of Blind Heinrich might be entirely unfounded, but I had at
the moment nothing better to go upon, and I decided that, in view of his
known association with Gould, whether he was mixed up with the matter we
now had in hand or not, a close watch upon him might provide some facts
of interest.

Upon my arrival in London from Paris, I had sought out Blind Heinrich,
who was now living in a boarding-house in Hereford Road, Bayswater,
close to Westbourne Grove.  In the same house was now living a dainty
little woman, a Belgian refugee, who was in very straitened
circumstances.  According to her own story, she had become separated
from her husband, a rich merchant of Brussels, before going on board a
boat at Ostend, during the terrible flight from Belgium in 1914.  Since
then she had been unable to obtain the slightest information about him,
and did not know even whether he was alive or dead.

For nearly three years, she related, she had remained in terrible
anxiety, which was rapidly wrecking her nerves and her life.  As a
refugee, a pitiful victim of the catastrophe which had befallen her
beloved country, she was existing upon English charity.  She called
herself Madame Taymans, and her old address in happier days was in the
Rue de Namur in Brussels.  But her real name was--Gabrielle Soyez!

Few women in the world could so perfectly adapt themselves to the
ever-changing demands of the Secret Service as Madame Soyez.  In her
present circumstances she was absolutely at home, for she had been
educated in part at a convent near Gembloux, and could assume the
Belgian accent to perfection.  It was an easy matter, therefore, for her
to pass for what she pretended to be.

In Hereford Road the Frenchwoman had established herself on my
instruction for the purpose of keeping a watchful eye upon the quiet,
long-haired, half-blind violinist, who, to all appearances, was eking
out only a meagre existence, and whose clothes were of that
shabby-genteel brand which usually betrays respectable poverty.  But we
knew enough of Heinrich's affairs to be convinced that the
shabby-genteel role was deliberately assumed for purposes of deception.
A splendid musician and a born teacher, Heinrich could command his own
terms, and, as a matter of fact, he made a good deal of money.  More
than this, he was well known in high circles of Society, where his
teaching abilities gave him the _entree_ to a large number of the best
houses.  And, of course, no one ever suspected that the half-blind old
fiddler, crawling from house to house in the aristocratic quarters in
which he found most of his pupils, was in reality the alert and
dangerous agent of the enemy which subsequent events revealed him to be.

CHAPTER ELEVEN.

AN AIR RAID ON LONDON.

One night of brilliant moonlight, I had just come in from a visit to a
theatre and was glancing through the evening papers before turning in,
when my telephone bell rang.  On replying, I found the caller was Madame
Gabrielle, and in consequence of the cryptic message she gave me I
abandoned the idea of going to bed and remained keenly on the alert.
For a full hour nothing occurred.  Then I heard the air raid warnings
for which I had been waiting and soon after the guns, distant at first,
but gradually drawing nearer, began to boom out their defiance of the
aerial invaders.

For nearly two hours the raid continued at brief intervals, as squadron
after squadron of Gothas came hurtling through the night sky on their
mission of hate.  As soon as the "All clear" signal was given, I hurried
out and made my way rapidly to Harrington Street, a quiet thoroughfare
at the back of Cadogan Square, with dark, old-fashioned houses, each
with the deep basement and flight of steps to the front door so
characteristic of a period of architecture which we may hope has passed
away for ever.

One of these houses was my objective, and I soon found it, for its door
was painted in a light shade, quite different from the hue of sombre
respectability which characterised all its neighbours in the gloomy
street.  It was noticeable that while nearly every house in the street
showed lights--the inmates had not yet got over their scare and could be
heard volubly discussing the alarms and excursions of the night--this
particular house was in total darkness and was as silent as the grave.

I soon located a deep doorway from which I, myself unseen, could keep a
close watch on the dark and silent house, and commenced my vigil.

Presently a man wearing a long light overcoat turned from the square
into Harrington Street, and, sauntering leisurely along, ascended the
steps of the house I was watching, and let himself in with a latchkey.
Five minutes later a second man passed close to where I was standing--
luckily my doorway was in deep shadow and he did not notice me--and also
entered the house.  Two others followed in quick succession.  One of
them I instantly recognised by his gait.  It was Blind Heinrich!

For four hours I kept surveillance, and during that time no fewer than
seven men arrived, each letting himself in with his latchkey.  It was
evident we had found out the meeting-place of some highly doubtful
individuals, whose obvious familiarity with the locality, coupled with
the strange hours at which they arrived, indicated quite clearly that
some nefarious scheme was afoot.  It was evident, too, that the old
Norwegian belonged to the gang.  And I began to feel assured that our
suspicions as to his real character were well founded.

It would have been difficult to find a better place for the meeting, for
Harrington Street, though readily accessible, led to nowhere in
particular, and was as quiet a thoroughfare as any in London.  No one
would notice the arrival at intervals of the men, policemen rarely
visited the street, and after midnight it was entirely deserted save for
the occasional arrival home of some belated resident.

It was not until five o'clock in the morning that the last man arrived
in a taxi, which, however, did not come along the street, but deposited
him at the corner of the Square.  A quarter of an hour later they began
to come out singly, at intervals of about five minutes, dispersing in
different directions.  There was no sign, however, of Heinrich
Kristensten.

"Well, _mon cher_ Gerald," said Madame Gabrielle, as she sat with me in
my flat in Curzon Street, soon after breakfast the same morning.  "You
see they receive warning of coming air raids and meet directly after.
Who are they?"

"Enemy spies, beyond any possibility of doubt," I replied.  "Our course
is clear now.  When the next raid is made we must follow them
individually and learn each man's identity.  I will make all the
arrangements.  Meanwhile, do you continue as you are and keep an eye on
the blind fiddler."

Madame Gabrielle returned to Hereford Road to continue her watch.  For
my own part, I set to work, and very soon discovered that the mysterious
house in Harrington Street was unoccupied and was to let furnished.  In
the guise of a possible tenant I went over it thoroughly, but could see
nothing suspicious, except that I ascertained that the caretaker was an
old compatriot of Heinrich's.  The owner, who had left London and was
now residing on the South Coast, was well known and his loyalty was
beyond dispute.  It then became evident that the caretaker was cognisant
of the secret meeting, if, indeed, he was not closely concerned in the
business, whatever it might be, that brought these men together in an
empty house at dead of night so soon after a raid, when most honest
people would be only too anxious to get to bed as promptly as possible.

It was obviously necessary that we should learn all we could about the
identity of the men who met in the empty house in Harrington Street, and
I was soon in touch with the Special Branch, and made all the necessary
arrangements for shadowing our suspects.

Four nights later another raid took place.  As soon as the Gothas were
gone we were all swiftly at our posts.  So thoroughly was the house
surrounded that a mouse could hardly have gone in or out undetected.
Yet there was no sign of a watcher, and anyone going to the house would
certainly be in blissful ignorance of the fact that he was under the
close scrutiny of the keen eyes of the Secret Service.  There is very
little clumsy "shadowing" about the Special Branch!

But we watched in vain.  No meeting was held, or if it was it was held
elsewhere.  The blind musician, it is true, left his room in Bayswater,
but he never reached Harrington Street.  The house remained all night
silent and apparently deserted.

I wondered whether the gang had by any chance discovered our activities
and taken alarm.  I was not very deeply concerned about it, apart from
the chagrin which the delay caused me.  Blind Heinrich, at any rate,
could hardly escape us, and, if the gang had for any reason changed its
place of meeting, I had little doubt that we should soon discover it.
But who had blundered?  I felt certain that it was not Madame Gabrielle,
and I did not think it could be myself.

One morning I received a note from the clever little Frenchwoman, asking
me to take tea with her at Hereford Road that afternoon, and adding: "I
have something to show you."

Of course I went, and we had tea together in the big drawing-room which
she used in common with the other guests in the boarding-house.  Several
of the old ladies who lived in the house were present.

Just as we had finished our tea, Madame exclaimed: "Do excuse me,
m'sieur!  I have forgotten my handkerchief."

Rising, she left me.  When she returned she was carrying a work-bag of
blue brocaded silk, which she placed upon her lap as she reseated
herself.  In her hand also she had an evening paper which she handed to
me with a casual remark that I might like to look at it while she got
her work ready.

I knew well enough that this was for the benefit of the other people in
the room, who, as usual, were keenly interested in any friends of a
pretty woman, and were scrutinising me pretty carefully.  I knew, too,
that Gabrielle had some further motive in her mind.  Accordingly, I
leaned back in my chair and read the paper diligently.

A moment later I noticed Madame Gabrielle telegraphing me in our "finger
Morse."

"Look carefully at the book showing in the mouth of my work-bag," she
signalled, "and get a copy at once.  It belongs to Heinrich, and I have
just borrowed it from his room.  He may be back at any moment--he has
only just gone out--and I must replace it at once."

She had casually left the mouth of her work-bag open.  It revealed the
title-page of an open book, published, as I saw, about seven years
before.  The title was _Royal Love Letters_.  I had never heard of the
volume, but I made a note of its title.

Madame Gabrielle, with an excuse, quitted the room for a few moments,
taking the book with her in her bag.  On her return she began talking
pleasantly about general subjects, but she was listening keenly, I could
see.  Soon we heard the front door slam, and a heavy shuffling tread
crossed the hall and went up the stairs.

"Blind Heinrich," she telegraphed; "I was only just in time.  He is
terribly watchful, and would certainly have noticed if the book had not
been on the table where he left it.  I often wonder whether he is as
blind as he pretends to be.  You had better go; if he comes in here for
tea, it is quite possible he may recognise you."  A quarter of an hour
later we were walking along Westbourne Grove together, and Gabrielle
told me the history of the mysterious book.  For several days, she said,
she had been following Heinrich, who had suddenly developed an amazing
interest in second-hand bookstalls.  He had gone into shop after shop in
various parts of London, asked a single question apparently, and come
out again.  At length she had managed to overhear him ask at one shop
for a copy of _Royal Love Letters_.  The shopkeeper had not the volume
in stock, and, as the request was such a peculiar one for a man of
Heinrich's temperament, Madame Gabrielle determined to run risks and
follow him daily.  He entered six more shops, making the same request at
each, and at length, in a dingy little by-lane in Soho, managed, to his
evident glee, to get what he wanted, and carried it back to Hereford
Road with obvious satisfaction.

"Why that particular book, and why so much trouble to get it?" said
Madame Gabrielle.  "What do you make of it, Mr Sant?"

I made nothing of it, except that there seemed to be good reasons why I
should get a copy at once.  If _Royal Love Letters_ interested Heinrich
Kristensten so deeply, it might well be that it would not be wholly
without interest for me.

My first care was to ring up Hecq on the official telephone and give him
full particulars respecting Heinrich's sudden interest in an obscure and
practically unknown volume published and forgotten seven years ago.  It
was quite clear that this was a hint we could not ignore, but I confess
I failed to see how it helped us.  But I was soon to learn more; Hecq's
quick brain had seen a possibility which I had overlooked.

At seven next morning, before I was out of bed, my telephone rang, and
Hecq once more spoke to me.

"I have been searching the papers, Sant," he said, "and I have found out
something that will interest you.  Listen carefully.  In the _Petit
Parisien_ five days ago there was an advertisement for the recovery of a
lady's gold trinket.  I have it here.  I'll read it to you," and he
read:

  _Perdus Ou Trouves_.
  Perdu Met.  Opera Breloque Or.
  Vialet 28 Marigny R. 100.

"Yes," I said, "I hear you.  But what has that to do with me?"

"Listen," said Hecq.  "There is nobody named Vialet at that address; we
found that out at once.  I have had nearly fifty of my people examining
every advertisement in the Paris papers issued just before Heinrich
began to display an interest in _Royal Love Letters_.  Now we have found
out that the advertisement I have just read to you conveys in
cryptogrammic form the message, `Buy _Royal Love Letters_.'  It would
take too long to explain it, but the paper containing that advertisement
would be on sale in London the very day on which, according to Madame
Gabrielle, Heinrich began to haunt the second-hand bookstalls on his
peculiar quest.  Rather curious, is it not?"

Curious it certainly was, and once more I found myself confronted with a
further enigma.  Why on earth should the book be advertised in
cryptogrammic form in a French newspaper?  How did Heinrich come to see
the advertisement, and how did he know the key to the code?  No doubt
the paper had accepted the innocent-looking advertisement without the
slightest suspicion that it was anything but the genuine announcement it
purported to be.  It was impossible to overlook the coincidence between
the appearance of the advertisement and Blind Heinrich's sudden deep
interest in a forgotten book.

Next day I started out in search of a copy of _Royal Love Letters_.  Of
course I failed to get one: it had been out of print for years, as it
had been published privately and comparatively few copies had been
printed.  However, I sent wires to some twenty provincial dealers in
second-hand books, and at noon next day had a reply from a dealer in
Birmingham, offering me a copy for four and sixpence.  I wired the
money, and next morning received the shabby little volume.  Little did I
realise what a dividend my investment of four shillings and sixpence was
going to pay me!

On reading the book through, I found it was merely a monograph on the
published love letters of various royal personages.  It was as dull as
the proverbial ditch-water, and I was not surprised at the difficulty
both Heinrich and myself had experienced in securing copies: the wonder
was that any had escaped the fire or the waste-paper basket.  But the
very fact made Heinrich's interest in the book the more suspicious.  It
conveyed nothing to me, it is true, about Gotha raids on London, but did
it convey anything to Heinrich, or was it the means of conveying
anything from him to someone else?

I called up Madame Gabrielle on the 'phone, and after she had arrived
and examined the volume, we went out to lunch at the Ritz.  Across the
table I told her of the curious advertisement in the _Petit Parisien_,
whereupon she exclaimed:

"Why, Kristensten reads that paper regularly.  I often see him with it.
He goes down practically every column of it with his big reading-glass!"

"That settles two points, anyhow," I said.  "The first is that he uses
that paper for receiving, and perhaps for sending messages.  The second
is that he knows the spy-cipher used in drawing up the advertisement.  I
am beginning to feel that this out-of-print and forgotten book will, if
we watch carefully, supply us with a very interesting line to follow."

And, ringing up Hecq, I told him about the latest development.  He was
keenly alive to the possibilities of the new situation.

CHAPTER TWELVE.

THE SECRET OF THE RIBBON.

Our new discovery seemed to me so remarkable that I lost no time in
impressing upon Madame Gabrielle the imperative necessity of the closest
possible scrutiny of Blind Heinrich's actions.  I was more than anxious
that we should not lose sight of him for an instant, and that I should
be kept fully informed of his every action.  For by this time I was
firmly convinced that, through some medium which we had yet to discover,
he was in some way keeping up communication with the more active agents
of the enemy.  And if we could but discover the channel through which
the stream of communications flowed, it would not be long, I felt sure,
before we had the key to the mystery in our hands.

Suddenly, and without any obvious reason, Heinrich completely changed
his habits.  Hitherto always on the move, he took to remaining indoors
all day, hardly ever going out except for a short stroll in the evening.
He met no one and apparently spoke scarcely a word to anybody.  What
his numerous pupils thought of his sudden neglect of them I cannot say.
But it was clear enough that something important must have occurred to
induce him thus suddenly to abandon what was, professedly at any rate,
his sole means of livelihood.

I was discussing him--he was almost invariably our sole topic of
conversation nowadays--with Madame Gabrielle as she sat in my room one
morning.

"I cannot conceive of any reason," I said, "why Heinrich should have so
suddenly changed the entire routine of his existence.  It looks to me as
though either something very important has happened or that he is
expecting important news.  Yet he receives no messages; he never gets
even a letter or a telegram."

"There is only one fact that is peculiar," said the smart Frenchwoman.
"You know I have been looking after him pretty closely lately.  Well,
whenever he goes out, though he appears to wander about quite aimlessly,
he invariably contrives his walk so that it takes him through Lembridge
Square.  He never misses."

"Does he always go the same side of the Square?"  I asked.

She replied in the affirmative, and I decided to have a look round the
Square for myself at once.

That same afternoon found me on the scene of Blind Heinrich's daily
walk.  The Square itself varied little from hundreds of others in
London: it showed every evidence of dreary respectability common to half
the squares in London.  Two things, however, attracted my notice.

In the ground-floor window of one house was a big brass cage containing
a grey parrot, which was insistently emitting the hideous noises common
to the parrot tribe.  In a similar window about a dozen houses away was
a case containing some old-fashioned wax flowers beneath a glass dome,
evidently a survival from the ornamental style peculiar to the early
Victorian epoch to which, indeed, the whole dreary Square seemed to
belong.

There was nothing to offer a lucid explanation of why Blind Heinrich
should choose such a path for his daily ramble.  There were dozens of
other far more attractive promenades within easy walking distance.  Yet
here, unless my instinct entirely misled me, was the solution to our
riddle.

Day after day I followed the old fellow's route.  I even went so far as
to shadow Heinrich himself more than once and verified Madame
Gabrielle's observation.  No matter which way he started out, he never
failed, on either the outward or homeward journey, to pass along that
particular side of the Square.  Yet he never spoke to anyone, and I was
morally certain that no signal was ever made to him from any of the
houses.

On the fourth day I noticed a slight fact.  The ring on the top of the
parrot's cage was tied with a big bow of yellow ribbon.  Three days
later it was altered to dark blue.  On the eighth day it had returned to
yellow again.

Why these changes?  Were they signals?

That night enemy aircraft crossed the south-east coast, but their
attempts to reach London were defeated by the terrific fire of the
anti-aircraft guns and by a swift concentration of our fighting
aeroplanes, which broke up several successive squadrons, and sent the
raiders hurrying home again.

Several of my capable assistants then took over the task of finding out
all that was known regarding the house in Lembridge Square.  Forty-eight
hours later I had a full report.  I learned that the man in whose room
the parrot lived was one of the mysterious band who foregathered to meet
Kristensten in the empty house in Harrington Street.  He was then
dressed as a special constable, a part which, by the way, he had no
right whatever to play.  He bore the thoroughly English name of Mostyn
Brown, and was in business in the City as the agent of a Manchester firm
of cotton merchants.  Apart from the fact of his presence that night in
Harrington Street, nothing that the most exhaustive inquiries revealed
suggested in the smallest degree any association with agents of the
enemy.  To all appearances he was a perfectly respectable City man, in
no way different from thousands of others.  But--there was a very big
but: what was his business in the dead of night in an empty house in the
West End in company of a suspected German spy?

A few days later the men who were keeping the houses in Lembridge Square
and Hereford Road under surveillance sent me a strange report, which set
me thinking deeply.  By some means--whether he suspected he was being
watched or whether a lucky chance favoured him, we never knew--Blind
Heinrich managed to elude the unwearying vigilance of Madame Gabrielle
and arrived alone, evidently in a hurry, at Westbourne Grove.  Here he
hailed a taxi and was driven to Waterloo Station.  There at the
booking-office on the loop-line side he had met a short, fat man, to
whom, after a brief conversation, he handed a bottle wrapped in white
paper.  They remained in conversation a few minutes longer and then
parted.  The fat man was followed to the tube railway and thence to
King's Cross, where he had bought a ticket for Peterborough, and left by
the five-thirty express.

Why Peterborough, I wondered?  There were certainly no facilities there
for anyone engaged in Germany's nefarious work.  But attached to the
report was a snapshot--taken secretly, of course--which showed me at
once that the little fat man was apparently a sailor, "camouflaged"
hastily in a badly fitting overcoat and a cloth cap.  That gave me a
further clue.  I took down a Bradshaw, and, glancing at the train by
which the little fat man had travelled, made an interesting discovery.
It was the Newcastle express.  I began to see why the mysterious little
man had booked to Peterborough.  That afternoon I ascertained that the
parrot's cage in the house in Lembridge Square sported a broad ribbon of
yellow satin.  At midnight I rang up Hecq at his house at St Germain,
and asked him to send Aubert the detective over at once.

An hour after midnight came another air-raid alarm--the second to
coincide with the appearance of the yellow ribbon.

Now one coincidence of this kind may mean nothing.  Two begin to be
suspicious.  A third is convincing.  I found my suspicions deepening
into certainty.

Directly the air-raid warning was given, our watchers in Harrington
Street were keenly on the alert, but, though they watched all night,
there was no meeting of the mysterious men in the empty house.  I
guessed the reason.  The raiders were again driven back before they
could reach the Metropolis, and, therefore, there was no news to be
gathered for transmission to the authorities in Berlin.  Everything now
pointed with increasing certainty to the house in Lembridge Square as a
focus of enemy activity.

Directly the "All clear" had been sounded over the London area, Heinrich
left Hereford Road, and, according to Madame Gabrielle's report to me,
hurried round to the house of the grey parrot.  He remained there about
half an hour, and then retraced his steps home in the waning moonlight.

Thus mystery followed mystery.  What was the meaning of the various
coloured bows on the parrot's cage?  For that they had a very definite
meaning I no longer doubted.  It seemed, indeed, tolerably clear that
the yellow ribbon betokened a coming raid.  And evidently the half-blind
old musician was a close friend of the manufacturers' agent.  But who,
in reality, was the mysterious Mostyn Brown, and, if he were indeed an
enemy agent, how had he managed to elude the close watch that had been
set upon him?

It had struck me that the house which sheltered the grey parrot might
conceivably conceal a wireless plant of sufficient power to convey a
message to a submarine lurking off the coast.  Such a plant need not be
a conspicuous affair.  But one of my agents, posing as an official of
the Metropolitan Water Board, had been able to negative the suggestion,
and I confess I found myself still hopelessly puzzled as to the means by
which information of the damage done by the raiding aircraft was so
speedily and so accurately conveyed to the enemy.

By this time Aubert had arrived from Paris, and had taken an obscure
lodging in Chessington Street, a dingy thoroughfare off the Euston Road.
By appointment I met him late one night at the corner of Grey's Inn
Road and Holborn, and, having explained to him briefly what had
occurred, told him to hold himself in readiness for instant action.

The apparent abandonment of the secret meetings in Harrington Street was
a source of considerable anxiety and chagrin.  I was particularly
anxious about them.  We had several of those who had taken part in the
first meeting under close observation, but had learned nothing about
them sufficient to justify our taking strong action.  Most of them,
indeed, seemed to be of the same apparently blameless type as Mr Mostyn
Brown, and it was evident that if they were indeed enemy agents they had
been selected or appointed by a master-hand at the game of espionage.
And I wanted badly to gain some more information about them.

Madame Gabrielle was ever on the alert, and soon it appeared from her
report that the blind fiddler was expecting another raid.  The ribbon
bow on the parrot's cage changed to dark blue, and remained so for six
days.  On the seventh it was replaced by yellow.  That night the old man
remained in his room reading for hours after all the other inmates had
retired.  But that night no raid was made.

I now began to think that it would be well if I took the mysterious
Mostyn Brown under my own special observation.  For a week during the
moonless nights I shadowed him closely.  I found out that he was a
member of a certain third-class City club, frequented by a large number
of "pure-blooded Englishmen" who happened to bear German names--of
course they had been naturalised--and very soon my name appeared on the
club books.

It was not long before I managed to scrape acquaintance with Mostyn
Brown over a game of billiards.  I cultivated his friendship eagerly,
and very soon we were on excellent terms.  As a matter of fact, I wanted
an invitation to his house, and at last I got it.

I spent there one of the dullest evenings of my life, an evening, as it
happened, entirely wasted.  Beyond noting that the ribbon on the
parrot's cage had again turned to blue, I saw nothing of the slightest
interest.

The next night, however, I made a discovery.  Dropping in at the club, I
found Mostyn Brown engaged in a game of billiards with a man whom I knew
in the club as Harry Smith.  A bullet-headed, bespectacled person, with
hair standing erect as the bristles of a blacking brush, Smith looked
the typical Hun, and I very soon decided in my own mind that Heinrich
Schmidt was probably the name by which he was first known to the world.

Suddenly a dispute arose about some point in the game, and in a moment
words were running high.  Half a dozen spectators noisily joined in the
altercation, and the room was a Babel of dispute.  I saw my chance.

Taking Mostyn Brown's side, I suddenly interjected a sentence in German.
Apparently hardly noticing the change in his excitement Mostyn Brown
replied in the same language, and his accent told me at once that he was
not of British birth.  There was no possibility of mistake, for, however
well the Hun may speak our tongue, he will inevitably betray himself
when in a moment of excitement he lapses into his own language.

My suspicions of Mostyn Brown were naturally intensified a hundredfold
by this discovery.  Of course, I redoubled my efforts, and was in daily
conference with certain highly placed people in Whitehall, whose
curiosity was now fully roused, as well as with my own agents, the
vivacious Madame Gabrielle and the slow, but painstaking and relentless,
Aubert.  The watch on the suspects became closer than ever, and I was
convinced that, try how he might, none of them could move, practically
speaking, without full details of what he was doing reaching me in the
course of an hour or two at most.  And I was ready to strike hard at the
earliest moment when decisive action might seem justified.

For the moment, however, there was nothing to be done but watch and
wait, tense and expectant, while night by night the moon drew nearer and
nearer to the full.  Thanks to the information I was able to place
before the authorities in Whitehall, there was little chance of the
anti-aircraft defences of London being caught napping, while the secret
signal I had discovered--the changing of the coloured ribbon on the
parrot's cage at Mostyn Brown's house in Lembridge Square--would be
almost certain to give us warning of any long-arranged raid in force.
Apart from the sequel, the worst we had to expect was a sudden dash by a
few machines in the event of an unexpected improvement in the weather
rendering such a course possible.  But with regard to the big raids,
involving days of patient preparation, settled weather, and most careful
and thorough organisation, we felt tolerably sure that the tell-tale
ribbon would give us the warning we wanted.  So it proved in the event,
and once again the Hun's trickiness brought his carefully planned scheme
to failure.

CHAPTER THIRTEEN.

HOW BERLIN OBTAINS INFORMATION.

At last the day--or rather the night--which we had been expecting came.
The sun had risen in a cloudless sky, and all day long had poured down a
fierce flood of heat and light.  London was stifling.  Everyone seemed
to be the victim of heat lassitude; tempers were decidedly short, and
even the most amiable of people seemed suddenly to have developed
raw-edged nerves.  Added to all this was an uneasy presentiment of
danger; "There will be a big raid to-night," was the thought in the back
of everyone's mind.

In order to avoid arousing Mostyn Brown's suspicions that his house was
being watched, we had given up, apparently, all observation on the place
during daylight.  But not in reality.  In a house on the other side of
the Square, directly facing that occupied by Mostyn Brown, I had hired a
room on the third floor, and from the window, with the help of powerful
field-glasses, we could keep the house under the strictest watch.  We
had not even to enter the Square to reach our tower of vantage, for
there was a back entrance from an adjoining street.

Towards this eyrie I had bent my steps, and on arriving I found Aubert
in a state of suppressed excitement.

"Look!" he said, handing me the glasses, and, taking them from him, I
levelled them at Mostyn Brown's room.

The ribbon on the parrot's cage had been changed to yellow!

But this was not all.  The sun shone full on the window of Mostyn
Brown's house and his room was strongly illuminated.  The field-glasses
showed us that Mostyn Brown was at home, a most unusual thing in the
day-time, and that with him was Blind Heinrich.  How Heinrich had got
there we could not imagine.  Aubert had not seen him enter.  They were
seated on chairs drawn up to the table, and were poring intently over a
book, apparently making memoranda on sheets of paper.  As we watched,
Madame Gabrielle, habited as a coster girl and carrying a huge basket of
flowers, came slowly along the Square, past Mostyn Brown's house and
round past the house in which we were seated.

I saw her flutter a signal, and, with her arm resting naturally on the
side of the basket, she rapidly tapped out a message with her nimble
fingers.

"Heinrich has been with Mostyn Brown for the past two hours," she spelt
out.  "He came straight from Hereford Road and went into the next house
from the back."  Evidently there was some way of communication at the
rear of the two houses.

I had now no time to waste, and, leaving Aubert and Madame Gabrielle to
keep the necessary watch, I hurried off to Whitehall, where I was soon
in deep talk with the astute and enterprising chief of the London
defences, a keen officer who by sheer merit had forced himself to the
very front rank in aircraft service.

"Good!" he said, when I had told him my news.  "I think we shall give
them a surprise to-night.  Perhaps you would like to see how we work.
Sit down for a bit."  And he turned to his big table, on which stood a
telephone.

For the next half-hour I watched him, fascinated with his sure grasp of
London's intricate defences, and amazed, though I had thought I knew his
capability, at the swiftness and decision with which he issued what to
me seemed a veritable jumble of orders.  To centre after centre of the
aircraft defences he spoke a series of numbers, so bewildering in their
speed and complexity that an enemy agent seated in the very room could
not have gained a scrap of information.  Even to me, familiar as I am
with almost every branch of code work, it was a veritable revelation.

"I think we are ready for them now," he said finally, wiping the
perspiration from his face, and I could see that even to him the strain
had been severe.  How well he had done his work all England was to know
the next day, though the public never even suspected the magnitude of
his task.

There was now nothing to do but wait; our traps were set, and it
remained to be seen whether the enemy would walk into them.  I made my
way to my chambers for a few hours' rest and was soon deeply asleep.

At half-past nine Burton, my man, roused me.  "The first warning has
just come in," he said.

I dressed swiftly and sat down to snatch a hasty supper, knowing well
that it might be many hours before I tasted another meal.

It was exactly ten o'clock when the report of the first maroon broke the
stillness, and London, with one accord, hastened to cover.  Ten minutes
later the streets were deserted, and a midnight hush reigned supreme.
The great city seemed a city of the dead.

As we listened a faint, distant boom struck softly on our ears.  The
strafe had begun!

Suddenly, far away to the eastward, a searchlight flickered up into the
sky; another and another followed in rapid succession, and soon the
entire sky was covered and chequered by dozens of wavering pillars of
flame, moving to and fro, methodically searching the heavens as though
moved by a single hand.  Far above us I caught the soft purr of an
aeroplane, evidently one of our own, for the sound was quite different
from the deeper and rougher note of the Gothas.

Suddenly, with a deafening crash, half a dozen guns barked
simultaneously, and, looking out, I saw far away, seemingly caught on a
pencil of living light, the ethereal butterfly shape of an enemy
aircraft.  A second later, in quick succession, came the unmistakable
sound of bursting bombs.

In the midst of the tumult a single tiny light showed for a moment far
up in the sky, just outside the ring of shrapnel that was bursting all
round the enemy craft, now hopelessly entangled in the beams of a dozen
converging searchlights, and, dive and drop as it would, utterly unable
to escape from the zone of effulgent radiance in which it seemed to
float.

Instantly every gun was silent!  We caught the crackle of a machine-gun
far up in the air, and a moment later the enemy machine burst into a
lurid sheet of flame, and the blazing mass pitched headlong to earth
amid a roar of cheering from watchers, who in thousands had braved all
possible danger to see the aerial fight heralded by the outburst of
machine-gun fire.  It was obvious that one of our sentinel aeroplanes,
perched far above the raider, had caught sight of him in the
searchlights, and, swooping swift as a hawk on his quarry, had sent the
Gotha a fiery run to the earth twelve thousand feet below.  I learned
later that the Gotha had fallen in Essex, the three occupants calcined
to cinders in the flood of blazing petrol.

That was the extent of London's excitement for the night.  It was not
until some hours later that I learnt that no fewer than eight squadrons
of Gothas, each consisting of four machines, had started out on their
errand of murder for London.  Only a single machine got through, and
that now lay a heap of ruins.  The rest had been split up by gun fire,
caught in the beams of endless searchlights, harried to and fro by a
vast concentration of British fighting planes swiftly assembled when the
warning of the yellow ribbon had become known, and had been relentlessly
chased homeward in utter disorder.  Their repulse was a triumph brought
about by Colonel --'s masterly effort at organisation, when I conveyed
to him in Whitehall the news which had reached me through a simple
yellow ribbon tied to a grey parrot's cage!

Reports soon began to reach me in swift succession from my subordinates
in many quarters.  Hereford Road, Harrington Street, and Lembridge
Square were being carefully watched.  Madame Gabrielle and Aubert, the
latter dressed in the guise of a seafarer, were on the alert, with
dozens of other reliable agents, ready for anything at a moment's
notice.

Suddenly Aubert rang me up on the 'phone.  I took up the receiver and
spoke to him for a few moments.

"Meet me at the corner of Harrington Street at five o'clock," I said.

We met in the grey light of dawn, and I soon learned that, with anything
like reasonable good fortune, we had in our hands the opportunity for a
great coup.  Blind Heinrich had gone to the house soon after the "All
clear" had been sounded.  He had been followed by Mostyn Brown, again in
the uniform of a special constable, and by five other men, one of whom
was the little fat man who had previously met Kristensten at Waterloo.

Now I had made up my mind that the little fat man was the intermediary
by whom the news collected by the other conspirators was conveyed
abroad, and it was essential that he should be caught red-handed.
Fortune had favoured us.  He had been the first to leave the house, had
walked to the Queen's Road Underground Station, and, as we learnt by
telephone, had travelled to King's Cross.  Here he was at present,
seated in one of the waiting-rooms, evidently intending to travel by an
early train.

Leaving the necessary instructions with regard to the conspirators still
in the house in Harrington Street, I accompanied Aubert to King's Cross.
The little fat man was still there, but just after seven he walked to
the booking-office and took a ticket for Peterborough.  Just behind him
in the queue of passengers were Aubert and myself.

When the express pulled out on its fast run to Peterborough--the first
stopping-place--Aubert sat in the same carriage as the little fat man,
apparently profoundly asleep.  I was in the next compartment, ready for
anything that might happen.

We were not much surprised when at Peterborough the little fat man
remained in the train, and so we continued our journey.  When tickets
were examined, the little man paid excess fare to Newcastle, and my
hopes of an important capture rose momentarily higher.

Hour after hour the express raced northward, and in the afternoon we
came to smoky Newcastle, where we were to be the witnesses of a strange
_denouement_.

The little fat man, closely followed by Aubert and myself, made straight
for the docks.  Here, in haste, he boarded a steamer, one of a service
which sailed regularly between Newcastle and Bergen.  He was evidently
known, for he was greeted without question by the men about the decks
and promptly disappeared below.  We followed, with several other
passengers, and very soon I sat in the captain's cabin, swiftly
explaining to "the owner" what had happened, and my suspicion of the man
who had just come on board with a freedom of movement which suggested
that he was one of the crew.

Captain Jackson was one of the men who have done so much to make the
North Sea service a model of everything that is implied in unswerving
courage and loyal devotion to duty.  A fine, bluff, grey-bearded skipper
of the very best type, he cared not a rap for the peril of mines and
submarines which dogged him at every yard of his journeys.  All he cared
for or respected was the Admiralty orders which gave him his chart
through the ever-shifting mine-fields; with those and his crew he was
ready to take his ship across to Norway and to defy the Huns to do their
worst.

His face grew grave and iron-stern as he heard my story, and, loyal
Englishman as he was, he instantly fell in with my suggestion for
trapping the scoundrel who was bringing disgrace on the good name of all
sailors by his infamous traffic with the agents of the enemy.

"George Humber is the name he goes by," said Captain Jackson, referring
to the man we had followed from Lembridge Square.  "He says he is a
Swede and has Swedish papers.  Let your French friend go below and help.
I'll see to it."

He called up the chief engineer, Andrew Phail, a dour, hard, bitter
Scotchman, who had followed the sea for forty years and cared for
nothing on earth but it and his beloved engines.  If ever a man loved
his machines it was Phail, and if ever a man was loved and trusted by
his subordinates it was he.  Hard though he was, his crew, with the sure
instinct of the sailor, recognised his sterling qualities, and would
have followed his lead through the worst storm that ever blew.  Indeed,
the--was emphatically what is known among sailormen as "a happy ship,"
thanks to the captain and chief engineer, and I was not altogether
surprised to learn that Humber was the only discordant note among the
crew; for some reason the men disliked him, though he did his work well
enough.

An hour later, having taken our mails on board, we dropped down the Tyne
bound for Norway.

I learned from Captain Jackson that Humber had signed on some months
before, and had made a number of trips across the North Sea.  He had
been in the habit of travelling to London each time the vessel reached
Newcastle, and at length this fact had aroused Captain Jackson's
suspicions, and he had made up his mind that this trip should be
Humber's last.  It was, indeed, but the end came in a manner which not
even Captain Jackson's keen wits had anticipated.

In the meantime I knew that Aubert, a splendid linguist, who could play
many parts, from that of an idler in Paris to a worker in a munition
factory, was somewhere below in the engine-room, certainly not very far
from Humber, and assuredly very much on the alert.

An hour after we left the Tyne mouth I was standing with some of the
passengers on deck, watching some winking signals as our convoy appeared
out of the misty twilight.  Of what the convoy consisted I could not
quite discern, but the Captain, before he ascended to his bridge, had
said: "Our friends will pick us up presently, and they will see us
safely across and look out for submarines."

The night passed without incident, and the next day proved grey and
windy.  Ever and anon one of our patrolling airships paid us a visit,
while three other ships, forming our convoy, stood by, with their deadly
guns ever ready to talk in deadly earnest with any submarine that might
venture to show her periscope.

At ten o'clock that night I was on deck watching a series of strange
flashes of light showing in the eastern sky, when a sailor approached,
and informed me that the Captain wanted to see me in his cabin.  I went
at once.

"Look here, Mr Sant!" the bluff old seaman exclaimed as soon as I had
closed the door, which he locked.  "I've been rummaging the ship.  Does
this interest you?"  And he brought out from the drawer in his table a
bottle of medicine.  It had apparently been recently bought from a
chemist, for it was wrapped up in the usual paper, which was still quite
clean and fresh, and sealed in the usual way.  "This was found by your
French friend concealed in Humber's trunk.  Your man would be up here,
only he is watching the fellow below, and as he is supposed to be on
duty his absence might rouse suspicions."

As Captain Jackson ended he handed me the bottle.

"It does interest me, indeed," I said.  "If Humber were ill enough to
need medicine--and he certainly does not look it--he would hardly have
brought this all the way from London without opening it."  And I thought
of the bottle wrapped in white paper which, on an earlier visit to
London, Humber had received from Blind Heinrich at Waterloo.

"I'll have a look at it, anyhow," I said.

My first precaution was to soften the sealing wax with a match, so that
I could unwrap the bottle without tearing the paper, and, if necessary,
so replace it that no suspicion that it had been tampered with should be
aroused.  The bottle might prove useless as a clue.  In that case we
should have to seek further, and to replace the bottle in Humber's trunk
in such a condition that he must inevitably see that it had been opened
would certainly arouse his suspicions and defeat our object.

I soon had the paper opened out.  The bottle of medicine seemed genuine
enough.  It bore the label of a well-known West End firm and the name of
Mr Humber.  I tasted the contents.

"Cough mixture" was my comment, and Captain Jackson at once confirmed
me.  "Humber never had a cough," he remarked reflectively.

"Now for the paper," I said, and began examining it.  It was perfectly
blank, and I was experiencing a pang of disappointment when, catching on
the paper the reflection of the swinging lamp, I detected in one corner
a faint, glistening line.  Lemon juice, I was confident.

Under appropriate "treatment" a number of neat figures arranged in
groups of three sprang into vivid prominence on the inside of the paper
wrapping.  They ran:

  123--5--8; 27--32--6; 46--23--11;
  294--12--3; 18--1--8;
  and so on.

I swiftly copied out the figures for safety, and handed the original
paper to Captain Jackson, who, on board his own ship, was, of course,
the supreme and unquestioned authority, and I wanted his full approval
and support to any action that might be necessary.  The figures were
meaningless as they stood, but I had not forgotten old Heinrich's
systematic search for that odd volume of _Royal Love Letters_.  I had my
copy in my bag and fetched it at once.

With such an obscure book as the key to the cipher there was no need for
any further elaborate precautions, and we hit upon the solution of the
difficulty at once.  On page 123 the eighth letter on the fifth line was
"B;" on page 27 the sixth letter in the thirty-second line was "r"; and
in a few minutes I had decoded the word "Brixton."  Going on, I found
that the message conveyed the news that Number 24,--Road, Brixton, had
been wrecked by one of the bombs dropped in the recent raid; that a man,
a woman, and two children had been killed.  The spots where the other
bombs had fallen were accurately described, and it was stated that they
had done no damage beyond blowing holes in the roads and bursting gas
and water mains.  Every word was accurate.

And the key to the whole problem was the mysterious advertisement for a
lost trinket in the _Petit Parisien_.  That simple advertisement, so
apparently innocent, had announced to Blind Heinrich the enemy's change
of code!  And without the book to which it referred no intelligence on
earth could have deciphered the disorderly mass of figures which lay
before our eyes!

"Well, I think we have got them now, Captain," I said, "and I am sure
the Government will be deeply obliged to you for your assistance.  But
how am I going to get this fellow?  If he lands in Norway he will be out
of our power."

"Come on deck," said Captain Jackson, with a laugh.  "Don't make your
mind uneasy about that."

I followed him up the companion-way gladder to the deck, now deserted by
all save the steersman and the officer on watch.

"Come up to the bridge with me," said the Captain.

Although it was so near the period of full moon the night was dark, the
sky being covered by a dense mass of heavy clouds.  Try as we would, our
eyes could not pierce the gloom, and we could see nothing a few yards
from the ship.  Though we had parted company from the destroyers long
before, we were, of course, travelling without lights in view of
possible danger, and only the binnacle lamp shed a soft radiance on the
ship's compass.  I was soon to learn, however, how closely we were
watched.

Captain Jackson entered the wheel-house and touched a key.  From the
masthead above a signal lamp flashed intermittently for a few seconds.
Instantly from the southward winked an answering gleam, and Captain
Jackson turned to me.  "That's a destroyer," he said, "and she is coming
up full speed."

For the next few minutes signals were exchanged with the racing
destroyer which was on our track, and soon I caught sight of the faint
glow from her funnels, and then the outline of her low, rakish hull as
she came abreast with us.  At a signal from Captain Jackson our engines
stopped, and soon we were lying motionless while a boat from the
destroyer pulled rapidly across the gap which separated the two vessels.

A few minutes later a smart naval officer came on board with four men.
We were soon seated in the Captain's cabin, and I rapidly gave him an
outline of what had happened.  His quick intelligence took in the
situation at a glance.

"I'll take your Mr Humber back with me," he said, "and you and your man
can come along."

But we were nearly to lose our man.  As the officer and his men entered
the engine-room Humber caught sight of them.  He started, but instantly
recovered himself.  As the lieutenant spoke to Phail, Humber watched him
closely.  I saw Aubert move noiselessly but swiftly behind Humber,
evidently ready for a tussle.  A moment later Phail beckoned Humber to
come to him.

Instantly the spy's hand shot to his jacket pocket, and, as it came out,
bringing with it a revolver, Aubert sprang.  The next instant the
revolver was on the floor and Aubert had Humber in a grip of iron.  Ten
minutes later, with Humber securely handcuffed, we were on our way to
the destroyer, and were soon thrashing our way at top speed for home.

There is little more to tell.  Humber proved to be a Swede named
Holmboe, and we clearly established the fact that he had been for a long
time acting as the travelling agent of the Berlin espionage bureau,
carrying information to Norway for transmission through the German
Legation in Christiania.  The conspirators in the house in Harrington
Street were all taken into custody, and we soon had all the threads of
their activities in our possession, including the key to the mystery of
Mr Mostyn Brown, whose connection with various little affairs of
espionage was clearly established.  Blind Heinrich, too, was at length
effectively unmasked, and, with the rest of the group, is now safely
under lock and key, with ample leisure to repent of the nefarious
business upon which they were engaged.

On this occasion, at any rate, the secret message failed to reach
Berlin, and I often laugh when I think of the amazement and anxiety that
must have been caused in the enemy's camp at the sudden silence of their
emissaries.  To-day we can afford to make them a present of the truth!

CHAPTER FOURTEEN.

THE GREAT SUBMARINE PLOT.

To be a success as a secret agent a wide knowledge of European hotels is
an absolute necessity.

You must, indeed, be familiar with the best hotel in every city of any
importance, and scarcely less important is the personal acquaintance of
the manager; for without his help you will inevitably find in your path
a thousand difficulties, small and great, which, with his friendly
assistance, melt almost insensibly away.  Duty and inclination alike
have led me to make a special study of hotel life, and I think I may
say, without undue egotism, that there are few _maitres d'hotel_ in
Europe with whom I am not on terms of acquaintance, and even in many
cases warm friendship.

I was especially fortunate in this respect in the situation in which I
found myself one sunny morning in June, 1917.  As the clock struck ten I
strolled out of a big hotel, which I will call the Waldesruhe, in
Lucerne, and wandered along the shady avenue beside the lake in the
direction of the Schwanen-Platz.

Luigi Battini, the manager of the Waldesruhe, was one of my closest
personal friends, and I should have stayed at the Waldesruhe at any time
I was in Lucerne quite apart from the particular business which had
brought me there on this occasion.  Luigi was one of those marvellously
efficient human machines which appear almost to reach omniscience in
everything connected, even remotely, with his profession.  He would give
his guests, off hand and without the slightest hesitation, minutely
detailed directions for the most complicated of journeys without opening
a time-table, and invariably his information was correct to the smallest
particular.  He knew at what stations every dining-car was put on every
train within a radius of hundreds of miles, and he impressed upon you,
in the far-off pre-war days, to remember that the train left Weis for
Passau twenty minutes earlier this month than the hour mentioned in the
time-table.

His memory, especially for faces, was prodigious.  Indeed, it was to
this that I owed the beginnings of our friendship.  Years before Luigi
had been a waiter at the great buffet at Liverpool where passengers from
the incoming American boats were in the habit of snatching a hasty meal
before joining the train for London.  I had arrived in England from New
York cold and hungry, and, owing to some delay about my baggage, was
unable to get to the restaurant until just before the London express was
due to start.

I had not realised how long I had been delayed, and had just taken my
first mouthful of the soup which Luigi had brought me when the bell
heralding the immediate departure of the train rang loudly.  With a
muttered ejaculation of annoyance I hastily threw down on the table the
price of my abandoned meal and rushed out, jumped into the train, and a
moment later was speeding Londonwards, still cold and hungry and in the
very worst of tempers.

Of course I promptly forgot the incident, and it was not until a year
later that I was forcibly reminded of it.  I had again arrived in
Liverpool from New York and hurried to the same restaurant for a meal.
By some queer chance I made for a table at which Luigi was still the
waiter.  I should not have known him, but he recollected me and our
previous meeting.

With a profound bow and a smiling flash of his exquisite teeth, Luigi
said quizzically: "Good evening, monsieur.  Has monsieur returned for
his dinner?"

I looked at him in blank astonishment for a moment, then burst into a
roar of laughter, as I remembered both him and the long-forgotten
incident of a year before.  The ice was effectually broken between us,
and when I left for London I felt I had made a friend of the smiling
Italian.  But it was years before I discovered how deep and loyal a
mutual regard had sprung out of a trifling incident.  But the best
friendships not infrequently owe their origin to some such triviality.

Time had slipped by since then, and Luigi had climbed the ladder until
the humble waiter was a power in the great cosmopolitan world of the
hotel.  But to me, at any rate, he was the Luigi of old; to others he
might be merely the official head of a perfectly appointed hotel, where
arrangements seemed to go by clockwork and no one ever heard of such a
thing as failure.  Always in a frock-coat, whatever the season, whatever
the hour of the day; always wearing the diamond pin given him by a
travelling monarch; always alert though never obtrusive; known to all
his guests, but familiar with hardly any--such was Luigi Battini.  And
he was one of Hecq's "friends."

I had gone to Lucerne on purpose to learn something from his lips which
he would not risk in the post, and what he had told me half an hour
earlier had set me thinking deeply.  It entirely confirmed certain
information I had been able to gain in London and Lisbon.

After a long and meditative walk, I seated myself on the _terrasse_ of a
cafe overlooking the lovely Lake of Lucerne, and, with a _bock_ before
me, wrote out a telegram as follows:

"Arthon, Paris.--Returning London fourteenth.--Casentino."

Having finished my _bock_, I strolled along to the chief telegraph
office near the station and dispatched the message.  To the uninitiated
it conveyed no other meaning than appeared on the surface, but its
receipt at the address for which it was destined set various elements of
machinery in motion.

On the evening of the fourteenth there stepped from the hotel omnibus--a
smartly dressed young Frenchwoman, carrying a little sable Pomeranian
dog and followed by a porter with her luggage.

Luigi met her in the hall, and, with his heels clicked together in his
usual attitude of welcome, received her with an exquisite bow.  She
engaged a room, signed the visitors' book in the usual way, and then
allowed Battini to conduct her up by the lift.  As she passed me our
eyes met, but without the slightest sign of recognition.  Even though
the newly arrived guest was none other than my smartest assistant,
Madame Gabrielle Soyez.

Next day, in consequence of a note I sent her, we met in one of the
sitting-rooms in the further, and at the present moment unoccupied--wing
of the hotel.  She then told me that her own sitting-room was next to
one occupied by a Swedish engineer named Oscar Engstrom, whom I had
watched in Lisbon a month before and who was now in Switzerland engaged
on some mysterious business which we had not been able to fathom.  We
strongly suspected, however, from various bits of evidence that had
reached us, that the man was in the pay of Germany at the moment, even
if he were not one of the regular German agents.

When I entered, Madame Gabrielle, smartly attired in a tailor-made gown
of navy-blue cloth and a very bewitching hat, was standing at the
window, with her pet dog beneath her arm, chatting to the immaculate
Luigi, gazing the while on the blue waters of the lake.

I found myself reflecting how typically French she was in every detail--
dainty in face and figure, immaculately dressed, and possessing that
indefinably vivacious great charm which seems to be the monopoly of the
cultured Frenchwoman.  She could throw it aside when she chose, such was
her wonderful versatility, and assume a mask of dullness and stupidity
sufficient to ensure that no one meeting her would give her a second
glance.  It was a valuable accomplishment, and more than once had
carried her safely through a difficult and dangerous situation.

To-day, among friends, she was her own sunny self.  "Ah, Monsieur
Gerald," she cried, springing forward to greet me, "our friend Luigi has
been telling me some very strange things--eh?"

"I have told Madame pretty well all I know," said the suave Italian, in
excellent English; "but it is not much.  Engstrom has engaged a room for
a lady friend--a Madame Bohman."

"Swedish also?"  I queried, with a smile.  "When does our friend expect
Mr Thornton, as he calls himself?"

"He is expected any moment," replied Luigi; "he has retained his room
ever since he left for London."

"Good!"  I said.  And we all three sat down and plunged into an
intricate discussion of every detail concerning the suspects and our
plan of campaign.

My instructions to Luigi were to keep a constant watch upon the comings
and goings of the Swedish engineer and his lady friend, while to Madame
Gabrielle fell the task of endeavouring to scrape acquaintance with the
latter on her arrival, in order to try to gain from some casual remark--
for we could expect nothing more--a hint of what was in progress.

Engstrom's lady friend, Madame Bohman, arrived in due course, and,
though she was quite unaware of it, we scrutinised her closely before we
gave her a chance of seeing us.  I saw at once that she was a complete
stranger to me.  Madame Gabrielle did not know her, and Luigi, with his
faultless memory for faces, declared positively that she had never
entered any hotel at which he had been engaged.

"A new hand, in all probability," I thought, "but none the less
dangerous on that ground if she knows her business."  Madame Bohman was
a tall, handsome, fair-haired woman of decidedly distinguished
appearance, and, from the scraps of her conversation which we overheard,
evidently well educated and well connected.  She had the blue eyes and
fair hair of the typical Swede, but blue eyes and fair hair are not
exactly unknown in Germany, and, though there was no ostensible reason
for it, I found myself wondering whether she was exactly what she
professed to be.  But the German spy bureau works with any tools that
come handy, and, even though Madame Bohman were the pure-blooded Swede
she professed to be, there was still no reason why she should not be an
enemy agent as well.  More than one Swedish "neutral" has been detected
in that category and paid the penalty!

CHAPTER FIFTEEN.

THE REAL MR ENGSTROM.

Three days after Madame Bohman's arrival, a special messenger brought me
from Hecq in Paris three reports which, when I had read them, reduced me
to a condition of blank despair.

The first was from the French Consul-General at Stockholm, who had been
instructed to make the closest possible inquiry into the _bona fides_ of
the shipbuilding and engineering firm of Engstrom and Linner, of Malmo.
His report stated that he had paid a visit to Malmo, and as the result
of his investigations there and elsewhere he had not the least doubt
that they were a first-class firm, and it was a fact of considerable
interest that they were employed by the Swedish Government upon several
important contracts.  No reason whatever could be suggested for doubting
their sterling integrity, and the partners had never shown the slightest
trace of pro-German bias, either as a firm or individually.  This seemed
a complete check to our suspicions.

The second report was from Aubert, whom I had left in Lisbon.  Dated
from the Palace Hotel, it read:

"I have kept constant observation upon the individual, Mr Thornton,
but, with the exception of the fact that he is acquainted with Halbmayr,
of the Koniggratzer-strasse--which, after all, may be quite innocent--I
see no reason to suspect him of hostile intent.  He has telegraphed
several times to Lucerne, addressing his messages to the name of Syberg
at the _poste restante_.  You could probably secure sight of one of
these; I cannot at this end.  He was visited a fortnight ago by a
Swedish lady named Bohman.  The latter may be a travelling agent of the
enemy, but somehow, after a close vigilance, I feel doubtful.  When
Thornton leaves I shall advise you.  It will be best for Garcia to
follow, as they have not met, and he is here for that purpose."

The third report was from a certain very alert English business man
named Charles Johnson-Meads, who had offices in Fenchurch Street,
London.  It was Johnson-Meads who, by a curious statement he made to me
one evening, in my rooms in Curzon Street, London, had first aroused my
suspicions that a deep plot, in which Engstrom and Thornton were somehow
implicated, was on foot.

Johnson-Meads' report read:

  "I have strained every effort to learn more of these people and their
  mysterious movements in London.  Contrary to my belief, I have now
  established the fact that Engstrom is, after all, the well-known
  Swedish engineer, and not the fraud I believed him to be."

This, of course, appeared to be tolerably conclusive, and I was inclined
to throw up the whole business at once and return to Paris, where other
work urgently awaited my attention.  It was clear enough from the report
of the French Consul-General at Stockholm that Engstrom and Linner would
not lend their name to any shady proceedings, while Johnson-Meads'
apparent certainty that Engstrom was really what he professed to be
seemed to cut away the principal basis of suspicion.

Half an hour later I met Madame Gabrielle and Luigi in the same private
room and showed them the three reports, which were as disappointing to
them as they were to me.  Of Madame Bohman, Gabrielle had failed to
discover anything which could give reasonable grounds for suspicion.
According to her own statement--for the resourceful Madame Gabrielle had
speedily scraped up an hotel acquaintance with her--Madame Bohman and
Engstrom were old friends, having known each other for years in
Stockholm.  Moreover, it was evident that Madame Bohman at least knew
Stockholm well, for Madame Gabrielle was intimately acquainted with that
city, and had no difficulty, by means of apparently artless
conversation, in testing the accuracy of Madame Bohman's knowledge.  To
all intents and purposes we seemed to be on a wild-goose chase, and I
expressed this view.

"There is nothing in it," was my verdict.  "I think the best thing we
can do is to give up wasting our time and get back to Paris at once.
You know there is the Morny affair waiting for me, and Hecq is anxious I
should take it in hand without delay."

"The Morny affair" was one of those queer financial scandals which have
been so rife in Paris during the war.  A Frenchman, hitherto of
unblemished reputation as a patriot, had suddenly come under suspicion
of trafficking with the enemy.  Questions and rumours had been flying
thickly in the Paris Press, as well as in the Chamber, and it was
urgently important that the unfortunate Mr Morny--for I, at least,
believed he was being slandered by a group of business rivals and
political enemies--should be cleared once and for all of suspicions
which were rapidly reducing him to a state of complete prostration.
How, later, I succeeded in completely vindicating his character, I hope
to tell at some future time--at present a full disclosure of the facts
might do untold harm.

But Madame Gabrielle, her feminine intuition busily at work, was not to
be easily put off.  She strongly dissented from my view.

"Yesterday," she said, "during Madame Bohman's absence with Engstrom at
Brunner, I took Luigi's master-key, and, entering her room, opened her
dressing-case and thoroughly searched her papers.  It is true I found
nothing of interest, save that there were letters from certain friends
in London, the addresses of which I have copied.  And I found this!"

"This" was a blank sheet of notepaper, which she produced, bearing the
heading of the Palace Hotel at Lisbon.

"You see," she said, "it has been very carefully preserved, for it was
enclosed in these two envelopes.  I wonder why?"

I took the blank paper from her and examined it carefully.  I found it
to be the ordinary hotel notepaper, exactly similar to that which I
myself had used in the hotel writing-room, during my recent visit to the
Portuguese capital.

"Well," I said, "I don't see how that proves, or even suggests,
anything.  We know perfectly well that Madame Bohman has been to
Lisbon--she herself makes no secret whatever of the fact, and she may
very well have brought away by accident a sheet of the hotel notepaper
and a couple of envelopes.  It is true she seems friendly with both men,
and there is undoubtedly some suspicion.  But is it sufficient to
justify action on our part, or even to give us good reason for staying
here and devoting to a very trivial matter valuable time which at the
moment we might be spending to much greater advantage in Paris?"

Luigi raised his dark eyebrows and shrugged his shoulders.  It was
obvious that he was entirely of my way of thinking, and, though he was
willing to do anything to help me and to put a spoke in the wheel of the
Hun plotters--for, like all patriotic Italians, he cherished the
liveliest hatred for the Austro-Germans--he was no fonder than I am
myself of the profitless task of chasing a will-o'-the-wisp.  But the
merry, go-ahead little Frenchwoman had her suspicions very thoroughly
aroused, and I knew well that when this was the case it was not an easy
task to allay them.

"I do not care, _mon cher_ Gerald!  There is evil work in progress,
somewhere; I am confident.  Why should Thornton be acquainted or have
anything to do with our arch-enemy, Ernst Halbmayr?  Remember how
cleverly he escaped you six months ago in Rotterdam!"

"But we trapped the woman," I rejoined grimly.  "And there was a firing
party at Versailles."

"And there is somebody to be trapped here also," persisted Madame
Gabrielle.  "You will surely not give up yet?"

While we were still discussing the matter a page-boy brought a telegram.
Luigi took it from the lad and, dismissing him, handed the message to
me.  It was from Aubert in Lisbon, and it conveyed the significant news
that this man Thornton had left for Lucerne, and that Garcia was
travelling by the same train.  "He has just sent a telegram to Syberg at
the _poste restante_," the message concluded.

After this, of course, there could be no question of our abandoning our
task.  There was evidently something afoot, and just as evidently
Lucerne was likely to be the scene of some lively incidents.

Luigi did not lose a second.  He rang the bell, and immediately another
page-boy appeared.

"Go at once to the _poste restante_," he said, "and ask for a telegram
for Syberg.  They know you come from me, so there will be no need of a
letter.  Don't forget the name--S-y-b-e-r-g.  And make haste."  The boy
disappeared instantly, and for a quarter of an hour we waited in
feverish impatience for his return.  When he came back he brought with
him the message we wanted.  Opening it, I read in French, as follows:

  To Syberg, Poste Restante, Lucerne.

  "Received good news from London.  Meads" (_the man in London whose
  suspicions had been aroused_) "is now with us, so business can
  proceed.  Leaving for Lucerne to-night.  Shall see T. in Paris to
  arrange further details and transit of machinery.  Thyra" (_the
  Christian name of Madame Bohman_) "will meet E.H."  (_was this Ernst
  Halbmayr_?) "at Geneva on the 15th."

This message was unsigned, but it confirmed the impression given us by
Aubert's wire that events were on foot, and at once the three of us
plunged with renewed energy into our plan of campaign.

"There can be no doubt," I said, "that `E.H.' refers to Halbmayr, and
probably he is directing the whole of the intricate affair."

"Very likely," said Luigi dryly, "but I do not see that we have much
more light on what direction against the British the conspirators, if
they really are German agents, intend to work."

"True, but that is just what we have to find out," I replied.  "From
what Johnson-Meads states, the plot in some way relates to the British
submarines.  At present I am just as much in the dark as you are.  If
Halbmayr is directing operations you may depend upon it that some really
serious coup is intended, for Halbmayr never troubles his head about the
small affairs.  Don't forget that next to Steinhauer he is the man the
Koniggratzer-strasse puts most implicit faith in."

Events were now moving rapidly.  I waited with anxiety for the arrival
of the man Thornton, whom I had never seen, for I was particularly
anxious to have a look at him.  I suspected very strongly that he was
one of the German Secret Service men masquerading under an assumed name,
and I was therefore particularly anxious for an opportunity of
identifying him.  I argued with myself that if he was mixed up with
anything big enough to call for the co-operation of Halbmayr he must be
one of the "big" men himself, and it was quite possible I might be able
to identify him, for personally or through photographs I was well
acquainted with most of the leaders of German espionage work.

Thornton at length reached the Waldesruhe, where he was greeted by the
urbane Luigi with all the evidence of distinguished consideration which
made the suave Italian so popular with his many patrons.  Thornton would
have passed for an Englishman anywhere, both in looks and language.  He
was perfectly dressed in clothes unmistakably British in cut, and spoke
the language to perfection.  This, however, was hardly surprising, for,
as we learned afterwards, he had lived in London ever since he was
fourteen.  He had, however, been brought up in circles which were
virulently anti-British, and had absorbed to the fullest extent that
poisonous hatred of everything English which so frequently displays
itself in the Hun who has made England his home of convenience.

He little suspected that the smiling Luigi, who so assiduously attended
to his comforts, was one of the secret agents of the Allies; that
another, in the person of myself, saw his arrival, or that in the turret
of the great hotel there was a small secret room containing a powerful
wireless set, which I sometimes operated myself.

I had to be very careful not to be seen by Thornton, for it was quite
possible, if my suspicions were well founded, that he might know me.
And it was well that I did, for I recognised him instantly as Emil
Brahe, a German agent of whom we had lost sight for some time.  He had
formerly been engaged on the Continent and was well known to our men,
though of late years he seemed to have dropped out of active work, and
we had lost sight of him altogether.  I realised now that we had been
cleverly tricked: we had believed him to belong to the Berlin branch,
while all the time he was living quietly in England, where he did no
"business" whatever, and was thus never suspected even by the astute men
of the Special Branch.

We had relied much on Madame Gabrielle's powers to extract information
from Madame Bohman, with whom she was already on excellent terms.  The
pair often sat chatting in the lounge, smoking each other's cigarettes,
and I knew the fair Gabrielle was keenly on the alert for any slip by
which Madame Bohman might "give herself away."  The Swedish woman,
however, was far too clever and would betray nothing.

Shadowing Thornton, or Brahe, to give him his right name, was Manuel
Garcia, a capable ex-detective of the Lisbon police, who was now an
agent of the Central Bureau of Counter-Espionage in Paris.

That telegrams were constantly passing between the Swedish engineer and
some people in Lyons and Marseilles I knew, and, indeed, I was able to
secure copies of some of them.  In this way I discovered that these
Swedes were on very friendly terms with a banker named Heurteau, who had
carried on business in Paris before the war, had afterwards escaped to
Zurich, and had long been suspected of being one of the paymasters of
the spy bureau in Berlin.

On the morning of the thirteenth, in consequence of what Madame
Gabrielle had told me, I took train to Geneva, where I put up at the
National.  Manuel Garcia followed by the next train, and early next
morning I received a telephone message from Madame Gabrielle telling me
that Madame Bohman had left the Waldesruhe and was due at Geneva at four
o'clock that afternoon.

As a result of this message Garcia and I watched the incoming train, and
my assistant followed Madame Bohman in a taxi to a small hotel in the
Quai de Mont Blanc.  An hour later Garcia himself took a cab to the
hotel so as to watch for the arrival of Halbmayr, the real antagonist
with whom our duel was being fought out.

Halbmayr, a short, stout, bald-headed man, with perfect manners and the
air of a _bon viveur_, kept his appointment punctually, arriving from
Bale the next day about noon.  As he knew me well, I was compelled to
remain in hiding, but from my window I was able, with a pair of good
field-glasses, to watch Madame Bohman and the German walking together on
the Promenade du Lac, evidently engaged in the closest conversation.
Garcia, of course, was not far away.

The pair remained together for an hour and a half, and I noticed with
amusement that the wily Halbmayr took particular care to select a seat
which stood quite in the open, with no shelter of any kind at hand
behind which an eavesdropper might lurk.  Garcia was thus, of course,
effectually kept at a distance, and had no opportunity of gleaning
anything from our enemies' conversation.

Apparently the two, in the course of their earnest conversation, arrived
at some definite agreement, for when they at length rose and parted,
Halbmayr returned direct to the station, where he had left his luggage
in the cloak-room, while the Swedish woman went back to her hotel,
leaving for Lucerne an hour later.

By the next train I also travelled with Garcia to Lucerne.  Immediately
on our arrival we all had a consultation, and we were deep in talk when
I received a startling message from Hecq in Paris.  It had been sent to
him by Johnson-Meads, who had promised to communicate with me through
Hecq if any further suspicious matter came under his notice.  The
message read:

"Cancel my last message; most urgent I should see you immediately."

Now Johnson-Meads' last message had reported him as being assured of the
_bona fides_ of Engstrom.  The "cancellation" of that could only mean
one thing--that the Engstrom we knew was a fraud, and that for some
sinister purpose he was trading on the good name of a perfectly
reputable firm of engineers in Sweden.

An hour later I was on my way to London.

I arrived there without incident, and for an hour sat with Mr
Johnson-Meads in his office in Fenchurch Street.

"I am afraid you will think me criminally careless, Mr Sant," he said,
"in the matter of my assurance that the man you know as Engstrom was
what he professed to be.  But I was deceived by a curious coincidence,
and can only offer as an excuse that I have not had your training in
solving problems of this kind.

"You will remember what I told you when I met you in Curzon Street?
Well, that remains true.  Where I went wrong was in identifying Engstrom
with the head of the Swedish firm.

"It so happened that I have business friends in Malmo, and, after our
conversation, being still very suspicious, I wrote to them asking for
information about Engstrom and Linner.  I soon received a reply, which
was in every way satisfactory, and my correspondent mentioned, quite
casually, that Mr Engstrom was actually in London and was staying at
the Hotel Cecil.  As I had that very day seen the man we now know as
Engstrom, that seemed to me to clinch the matter, and perhaps foolishly,
I dropped all suspicion.

"Now for the curious coincidence.  A few days ago I was going home by
train about six o'clock.  The trains, of course, were packed, and I was
`strap-hanging.'  We had just left King's Cross when, owing to steam in
the tunnel, our train ran with considerable violence into a train which
was standing in the tunnel.

"The smash was not serious, but the shock was severe, and I was thrown
right on top of a gentleman sitting on a seat close by me.  A metal
dispatch case he was carrying caught my face and, as you will see, cut
it very badly.  I was stunned for a moment, and when I came round I
found the stranger holding me up.  He tied a handkerchief round my face,
and very kindly helped me out of the train to a hotel, where he got me
some brandy, and I soon recovered.

"He had to go on, and as we were about to part he handed me his card.  I
slipped it into my pocket without looking at it, and went home, very
much shaken.  It was not until two days later that I looked at it.  It
read:

"Engstrom and Linner, Stockholm.  Oscar Engstrom.

"Now, Mr Sant," he went on, "_the Mr Engstrom who helped me was not
the man we both know as Engstrom_!  He did not resemble him in the
slightest degree.  I immediately tried to find Mr Engstrom, but found
to my dismay that he had left the Hotel Cecil and no one knew where he
had gone.  He was on a holiday tour, and when he tears a few days from
business he frequently disappears altogether for a week, in order to get
a complete rest from business cares.  I have wired Malmo, and all they
can tell me is that he will not be back for ten days.  Now what can we
do?"

I thought deeply for a few moments.  Obviously I must see the real Mr
Engstrom as soon as possible.  But there was no chance of finding him
immediately, and in the meantime much might happen.  I soon made up my
mind.

"I shall return to Lucerne at once," I said, "and go from there to
Stockholm in time to meet Mr Engstrom on his arrival.  There is nothing
else to be done."

Two days later I was back in Lucerne.  "Engstrom," his friend Thornton,
and Madame Bohman were still there, busy on their plot, whatever it was,
and entirely unsuspicious either of the urbane hotel manager or the
pretty little Frenchwoman who had apparently developed a lively
affection for the handsome Swedish woman.

One day I learned from Luigi that, in the course of a couple of hours,
Engstrom had received three telegrams, and had sent a reply to each of
them.  Of their purport Luigi could gain no knowledge.

Now, I was particularly anxious to get a sight of those telegrams, for
obviously they might throw a good deal of light on the business on which
Engstrom was engaged.  I laid my plans accordingly.

That same afternoon, with Luigi's assistance, I managed to transform
myself into a passable imitation of a very unkempt and dirty mechanic,
and as soon as the Swedish engineer left the hotel, about half-past
five--it was his usual habit to go out to take an _aperitif_--I took
Luigi's master-key, which unlocked all the doors in the hotel, and crept
noiselessly to Engstrom's room.  I was soon inside, and a few minutes
later, with the aid of my own skeleton keys, had opened the big leather
travelling trunk, and was hastily examining its contents.

A number of telegrams had been hastily thrust into the trunk.  I had
grasped my prize and was just about to shut and relock the trunk, when I
heard a sound behind me, and, turning, found myself face to face with
Oscar Engstrom himself.

And not only that, but I was looking straight into the barrel of a very
serviceable-looking automatic pistol, held without a tremor in
Engstrom's very capable hands!

CHAPTER SIXTEEN.

IN A TIGHT CORNER.

I was caught red-handed--caught as neatly as any _bona-fide_ burglar who
ever picked a lock!

I had opened the trunk of a fellow visitor with a skeleton key; I had
been caught in the very act of pilfering the contents.  Indeed, at that
very moment I held in my left hand a tiny leather box containing
Engstrom's diamond tie-pin and studs, while with my right hand I had
been delving into his big trunk.  Never was a capture neater or more
complete.  And, with the menace of the big revolver in Engstrom's hand,
and knowing something of my captor, I knew better than to attempt a rush
for escape.  I should never have reached the door alive!

"Well, and what does this mean?" harshly demanded the Swedish engineer,
in bad French, still covering me with his pistol.  "And who are you?"

Had Engstrom suspected who I really was, I knew he would have shot me
out of hand and chanced all consequences: indeed, he would have had
little to fear, for there would have been nothing more than a casual
inquiry into the shooting of a thief caught red-handed.  Moreover, dead
men tell no tales, and Engstrom would have had no difficulty whatever in
excusing himself by some hastily concocted story that I had attacked him
as soon as he found me plundering his trunk.  My disguise saved me, and
it was evident he had no suspicion that I was anything but a common
thief.

I broke instantly into a torrent of excuses, putting down the little
jewel box and the papers with as guilty an air as I could assume.  The
situation obviously required both tact and cunning, for I realised that
I was in a tight corner and that a slip would cost me my life.  I
pleaded desperate poverty; I was an honest workman driven to evil
courses by want; I am afraid I even invented a story of a wholly
mythical wife and family in the last stage of starvation.  Finally, I
roundly promised amendment of my ways if he would but let me go.
"Forgive me this time," I implored.  "Do forgive me--this will ruin me."

"You dog of a thief, I have caught you stealing from my room," was his
only reply.  "I shall call the manager," and he slammed the door and
pressed the electric bell.  "Send the manager here at once," he
commanded the messenger who answered the bell.

Luigi came immediately, and there was a great scene in which my friend
very cleverly worked himself into a state of virtuous indignation at the
slur I had cast upon his hotel's high reputation.  He assured Engstrom
that justice should be done forthwith, and actually handed me over to a
police officer, and I was at once marched off as a common hotel thief.

Guess my surprise when, as soon as we had turned the first corner, the
officer whispered: "Monsieur Battini has told me all the circumstances.
He did not telephone to the Bureau, but called me in out of the street.
Dash away from me in a few moments when we come to a lonely place, and I
will merely pretend to follow you.  But, monsieur, get away from Lucerne
as quickly as possible."

I smiled: Luigi had shown that he possessed a quick and ready
resourcefulness.  It was most fortunate that Engstrom, finding me with
my skeleton keys on the floor, and his jewellery in my hand, had failed
to suspect the truth.

I slipped away at the first convenient corner, and an hour later was
well on my way by the St Gothard route to Milan, the excellent police
officer undertaking to let Luigi know whither I had gone.  I learned
later that, when my "escape" was reported to him, Engstrom took the
matter very quietly, and, beyond roundly abusing the officer for letting
me slip through his fingers, did not propose any further action.  As a
matter of fact, having lost nothing, he was probably well content that
the affair should end thus.  I have no doubt that, masquerading in the
name of another man, publicity was the last thing he would desire.

Our problem now was how to deal with Engstrom and his associates.
Obviously to arrest them, even if we had good ground for doing so, would
have been to defeat our own object, for we wanted to find out all the
details of the plot upon which they were engaged.  But, as a matter of
fact, they had done nothing up to this moment to bring themselves within
the clutches of the law.  Engstrom, it is true, was posing as someone
else, but, so long as he did not attempt to profit by it, this was not a
criminal offence.  I decided to continue our investigations.

Reaching Milan, I put up at the Cavour, where, of course, I was well
known.  A few hours later I received a long dispatch in cipher from
Madame Gabrielle, and two days later an explicit letter from Luigi.  I
was also able to secure some further information regarding the
mysterious engineer and his friends, and this decided me to go to Sweden
myself and see the real Mr Engstrom.

My journey to Malmo was uneventful, and, arriving there, I lost no time
in repairing to the yard of Messrs. Engstrom and Linner, the engineers.
There, in the private office of the head of the firm, I soon found
myself face to face with the principal, Mr Oscar Engstrom.  He was a
short, dark, alert little man, with charming manners, and I took a
liking to him at once.  I had not previously decided on my course of
action, but after a few minutes' conversation I decided on a policy of
complete frankness.  As rapidly as possible, I told him the full story
of the man who had been using his name in London and on the Continent.

At first he expressed himself as completely puzzled.  He could not, he
said, imagine what the object of the gang could be.  They could hardly
commit the firm to anything which would profit themselves, for no one
abroad would act without inquiries.  At length I happened to mention
that Johnson-Meads had told me that the man had for disposal something
connected with submarines.

"With submarines!" he exclaimed in obvious surprise.  "Why, we have in
hand at this moment several submarine inventions, of which we own the
patents.  Two of them are completely secret, and they are in use only by
France and Britain."

This put a new aspect on the affair.  "I begin to see now," I said, "why
your name has been assumed.  Have you heard of any attempt to secure the
submarine secrets?"

"None whatever," replied Mr Engstrom.  "Moreover, it would be extremely
difficult, if not impossible.  One of the appliances with which we are
concerned is of such importance that, while we make the greater part of
it, a vital portion is manufactured in England, and the apparatus is not
put together until the whole is actually on the submarine for which it
is intended.  Consequently, unless a thief or spy secured copies of the
plans both here and in England he would be powerless to profit by
either.  I may mention that this arrangement was arrived at with the
British Admiralty at our express wish and suggestion.  I am quite frank
with you, Mr Sant."

"One more question, Mr Engstrom," I added.  "You are in a position to
know of any important inventions in connection with submarine work.
Have you heard of any recent invention which would bring it within the
bounds of possibility that your double is acting honestly and has really
something to sell?"

"That is out of the question," returned the engineer decidedly.  "Unless
the invention were German, in which case it would not come out of that
country, I think I should certainly have heard something of it.  Of
course, we have rivals in our business, but there is a certain amount of
freemasonry even among business rivals.  I know all the people who are
making submarine parts--there are very few who could or would tackle a
big invention.  Besides, if the man has an honest bargain to drive, why
should he assume my name?"

This argument was unanswerable.  But I confess I was still a long way
from guessing just what the bogus Engstrom and his friends were
plotting.

My next visit was to the Swedish police in search of information about
Madame Bohman.  Here, however, I was quite at fault.  It was evident she
was passing under an assumed name, and I could not succeed in
identifying her among the long array of photographs of known German
agents laid before me by the chief of the Swedish Secret Police.

Arriving at Bergen, I received, before I sailed for England, a long
telegram from Madame Gabrielle, telling me that Engstrom, Madame Bohman,
and Thornton had left for Paris.  Fearing that they would immediately
recognise her if she followed them, she had telephoned the news to Hecq,
and that astute official had promised to take the suspects under his own
wing for the immediate future, pending my arrival.

I proceeded to London, where, to my dismay, I learned that, although
Madame Bohman had arrived in Paris with Thornton, Engstrom was missing.

Twenty minutes later I was speaking with Hecq at St Germain over the
official telephone.  Three days later I heard that Hecq's men had
succeeded in running the elusive Engstrom to earth at Marseilles, where
he was staying at the Hotel Louvre et Paix under the name of Jansen, and
was constantly meeting a compatriot named Tegelmund.

The situation at this moment remained a complete puzzle so far as the
real objective of the gang was concerned.  On the one hand, we had at
Marseilles the mysterious individual who posed as the Swedish engineer,
Engstrom.  On the other, we had his known associates, Thornton and
Madame Bohman, in Paris.  Engstrom was living quite openly, with no
appearance of concealment, at a good hotel, but he was quite obviously
doing nothing and meeting nobody.  The other two, however, were just as
obviously lying low.  They had taken apartments at a very small and not
very reputable hotel in the Rue Royale, and both had changed their
names, entering France with new and apparently perfectly genuine Swedish
passports, issued only a few weeks previously.

Our next discovery was a staggering surprise.  One of our agents, who
had been watching Madame Bohman, came in and reported that, late the
previous night, she had left her hotel and walked swiftly to an obscure
cafe in the Quartier Latin.  She had entered the place, taken a seat at
a table by herself, and called for a glass of wine.  While she was
drinking it, a man, very untidy and apparently half intoxicated, lurched
up to the table and sat down facing her.  She took no notice of him
whatever, or he of her.  Calling a waiter, the man ordered a double
glass of Chianti.  Our agent, seated at an adjoining table, saw her then
glance quickly at the stranger, and a moment later she ordered an
absinthe.

Now, an order for a double glass of Chianti is unusual, especially in a
disreputable cafe in a low part of Paris, and it is hardly customary for
women to follow wine with absinthe.  Our agent was struck by the oddity
of the two orders and listened closely.

Directly the waiter had placed the drinks on the table and left, the
man, without even glancing at the woman, muttered something in an
undertone which our agent could not catch.  It was, however, evidently
sufficient, for the woman drank up her absinthe, and, rising, left the
cafe.  She took no notice whatever of the man, and he paid, to all
appearances, as little regard to her.  Apparently half overcome by
drink, he remained at the table, nodding drowsily, for a quarter of an
hour.  It was a clever bit of acting, but he forgot his eyes!  Our agent
caught a sight of them, and realised at once that the drunkenness was
feigned.

At length the man got up and lurched towards the door.  The police agent
at the same moment left by another exit into an adjoining street, and,
casually turning the corner in the direction the supposed drunken man
had taken, saw him a few yards ahead, walking steadily enough.

Five minutes later he had overtaken Madame Bohman, and, walking side by
side for a few hundred yards, they had a brief conversation and parted.

Our agent was in a quandary.  He had the strictest instructions not to
lose sight of Madame Bohman, but he was a man of intelligence, and
realised that a new factor had appeared on the scene.  Accordingly, he
decided to follow the man, and soon saw him enter a cheap
boarding-house, letting himself in with a latchkey.  Five minutes later
we had the news, and a couple of men were at once detailed to take up
the watch.  Madame Bohman, we soon ascertained, had gone straight to her
hotel.

The boarding-house which the mysterious stranger had entered was closely
watched all night.  The next morning the man came out, and was
immediately recognised as none other than Halbmayr himself!  How he had
got into France and Paris was a mystery, for the police had no register
of his arrival.  I may say here that this point was never completely
cleared up, but it was very generally believed that he was put ashore by
a submarine, and intended leaving in the same way.

We now had him safely enough; he could not possibly escape.  He was a
known spy, and there was ample ground for arresting him.  But this would
have made mincemeat of our plans, as Hecq saw plainly enough.

"Halbmayr is very dangerous," he declared to me as I sat in his office
the same day.  "Evil work is on foot somewhere, and our friend the
German is director of operations.  He would not dare to show his face in
France after meeting Brahe in Lisbon unless he were playing for a big
coup.  But, my dear Sant, what is his motive?  What is he after?  To
that question so far we have got no reply whatever.  And we _must_ find
the answer."

I agreed with my chief most cordially.  "Give him rope," I said, "and
see if he does not hang himself.  At any rate, he won't escape us this
time; we shall get him even if we don't learn his secret.  What worries
me is that he may have done his nefarious work, and inflicted untold
injury on the Allies before we nab him.  But we must take some chances."

"The telegram sent by Brahe, or Thornton, to Engstrom just before the
former left Lisbon mentioned two things," said my chief.  "The first was
that Johnson-Meads was with them--in other words, that his suspicions
had been allayed (which we know to be a fact)--and that `T.' was here in
Paris `to arrange further details and transit of machinery.'  What
machinery?  And who is `T'?  `T' must be Tegelmund, the man in
Marseilles.  We must look out for him."

CHAPTER SEVENTEEN.

"THE PLOT REVEALED."

Within a week the man Tegelmund, accompanied by Engstrom, arrived in
Paris and took up his abode in an obscure hotel near the Gare du Nord.
But, though we kept a careful watch upon the pair, Engstrom, ever
elusive and resourceful, suddenly disappeared!  For six days he was
absent.  Then, as suddenly and mysteriously, he appeared again at the
hotel.

Aubert, who had been detailed to watch Tegelmund, now reported that the
latter had been across to the Orleans goods station, inquiring about
some heavy cases of goods which had arrived from Lisbon.

"I have contrived to open one of the cases," he said.  "It contains some
complicated and apparently delicate machinery, with a small dynamo.
Apparently it is some sort of wireless plant, but, beyond that, I cannot
make head or tail of it."

At Aubert's suggestion I went late one night to the Orleans goods yard.
Aubert, by methods of persuasion not wholly original, had contrived to
make friends with one of the officials, and we had no difficulty in
securing access to the great goods shed, now silent and deserted, in
which the mysterious cases lay.  Prising open one end of the topmost
case, I inspected the contents as closely as I could with the aid of my
pocket flash-lamp.  Within was what certainly appeared to be a wireless
plant of some kind, but it was of a description entirely new to me, and
I could not see enough of it to gain any idea of its purpose.  Of course
we dared not risk unpacking it.  But we had made a great advance.  The
big cases could not be secretly moved, and our friend, the goods
official, undertook to let us know promptly when he received orders to
release them.

We waited in patience for a week, but still the cases remained untouched
and uncalled for.  Then came an incident which threw a flood of light on
the proceedings of our enemies, though it told us nothing of their real
motive; we were to learn that later.

One day I was strolling aimlessly along the Boulevard des Capucines,
when I heard my name pronounced in accents of delighted surprise.
Turning round, I instantly recognised an old friend in the person of
Captain A--, who was one of the experts attached to the submarine branch
of the British Admiralty.

"My dear Sant," he exclaimed joyfully.  "Who would have thought of
meeting you here?  I am alone in Paris.  I know no one and am bored to
death.  What have you got on hand now?  I thought you were in New York."

"I certainly didn't expect to meet you here," I replied.  "What has
brought you over?"

"Come and have some lunch, and I'll tell you all about it," he replied,
and we repaired to an adjoining cafe, where Captain A--promptly ordered
lunch in a private room.

"We've got a new thing on hand in the submarine line," he told me as
soon as the waiter had left the room.  "You know we have been trying
some experiments in German waters lately, and the Hun destroyers have
been so confoundedly active that our fellows have had to pass a lot of
their time sitting on the bottom.  As a consequence, some of the crew
have suffered terribly for want of fresh air.  We have a very good
system of purifying the atmosphere, but it is not sufficient owing to
the long periods the boats have to stay under water, and a number of men
have collapsed and died from suffocation.  Indeed, one boat only escaped
with more than half her crew totally incapacitated."

I was keenly on the alert.  Was I, I wondered, coming to grips at last
with our problem?

"Well," Captain A--went on, "we have been offered a new apparatus,
which, if half of what the inventor tells us is true, will enable us to
give the Hun a very bad time.  We are assured that by its help a boat
can stay under water for five days without the slightest risk."

"Five days!"  I repeated incredulously.  "Why, it's impossible!"

"So I thought," he rejoined, "but when Engstrom and Linner vouch for
anything, you've got to listen."

"Engstrom and Linner!"  I gasped.  Things were getting "warm" indeed.

"Yes," he replied.  "Mr Engstrom is in Paris now with his invention,
and we are going to test it off Havre."

Then I sprang my mine.  "Would you be surprised to learn," I asked, as
coolly as I could, "that your Mr Engstrom is not Mr Engstrom at all,
but a German agent passing under his name?"

I have seen a good many badly surprised men in my life, but I never
witnessed before or since such a spectacle of hopeless astonishment as
Captain A--presented when he grasped the full significance of this
announcement.  He sat staring at me, his mouth wide open, and with
dismay written legibly on every line of his countenance.

"But, Sant," he gasped.  "Are you sure?  Mr Engstrom came to us in
London and told us all about it.  He explained that the inventor was a
Spaniard who would not trust the `neutrality' of the Spanish Government
in the matter, and that he had brought his invention to Engstrom's with
the idea of getting the best terms from one of the Allies."

"I have no doubt that the man posing as Engstrom came to you," I
replied.  "But, none the less, he is not Engstrom at all."

"Then what is his game?" countered A--.  "He has offered us the fullest
test before we adopt his machine, and has not asked for a cent."

"That remains to be seen," I answered, "but it bodes no good to the
Allies.  What does he propose?"

"He has offered to instal the apparatus on one of our newest types,"
replied A--, "and she is on her way to Havre for the purpose.  We are to
make any test we like, and, in fact, I am here to see the test carried
out.  The only condition he makes is that his machinery shall be sealed,
and not opened until after the test has proved it to be satisfactory."

I began to see light.  "Did he propose to go with you?"  I asked.

"No," replied A--, rather ruefully, I fancied.  "He said the machinery
was so perfect that it would practically run itself from our electric
accumulators, and that he would give us an absolutely free hand with
it."

"I wonder how many of you would have come back?"  I said meaningly.

A--swore fervently, and I saw by the gleam in his eyes that he was fully
awake to the possibilities of the trap into which he had been so nearly
led.

Our task now, barring some unforeseeable contingency, was fairly easy;
there was a good prospect of ensnaring our foes in the pit they had so
skilfully dug for us.

"The matter is up to you now," I told A--.  "I'm going to drop out till
the very last minute.  But I shall be with you then.  It is of the
utmost importance that we shall do nothing to scare these very wary
birds.  What is your plan?"

"Well," said A--, "it seems to me I had better go ahead as if nothing
had happened.  The arrangement is that Engstrom shall take his apparatus
to Havre and instal it on E77.  We are then to put to sea for the tests,
and are to meet him later and inform him of our decision."

"That will do all right," I said.  "I shall come on board the submarine
before Engstrom arrives, and then I think we shall surprise him."

A--departed at once to make the final arrangements and I busied myself
in sending off some telegrams arranging for the final downfall of the
Hun plotters.

A week later I found myself on board E77 at Havre.  The mysterious cases
had been sent on, and with them came Engstrom, with Thornton and
Tegelmund, who professed to be interested in the venture--the former
financially, the latter as the inventor.  Tegelmund was in high glee at
being thus afforded an opportunity of putting his device to a thoroughly
satisfactory test.  We also had a big surprise in the arrival of
Halbmayr, who arrived in Havre under the name of Mennier.  That he
should have ventured on the scene at all showed how intensely interested
he was.

Engstrom declared that the fitting of the machinery would occupy fully
three days, and we, of course, humoured him in every way possible.  A--
made himself particularly agreeable, playing the part of host to
perfection, and it was evident that the conspirators never even dreamed
that their nefarious designs were suspected by the genial naval officer
who showed such an enthusiastic interest in the wonderful stories with
which they plied him on the merits of their great discovery.

The three days went by.  Four great cases of machinery had been duly
shipped on board, and Engstrom, Thornton, and Tegelmund spent many hours
daily at their work in the interior of the submarine.  Of course I could
not appear--I should have been recognised at once--but among the crew of
the submarine were a couple of the smartest men of the Surete, who kept
the bogus engineer and his associates under the closest scrutiny.  They
reported to me that Engstrom appeared to be the only one of the three
with any great amount of mechanical knowledge, and that, while Tegelmund
worked assiduously at his machine, the others spent most of their time
carefully examining the details of the British vessel, in which they
showed the greatest interest.  I began to get at last an inkling of the
plot!

The fourth day dawned--the day of the _denouement_.  Early in the
morning I slipped on board the submarine, and when the two conspirators
arrived we made our coup.

Engstrom, when he came on board with Tegelmund, found himself suddenly
confronted by the Commander, with a stalwart bluejacket standing on
either side of him.  He was curtly informed that he could not go below.

"But you promised!" he shrieked, livid with vexation.

"True!" said the Commander.  "But you call yourself Oscar Engstrom, of
Malmo, and I happen to have the real Mr Engstrom here."

The engineer went white to the very lips as Mr Engstrom, who had come
post-haste from Stockholm in response to my urgent cable, emerged from
behind the conning-tower, closely followed by myself.  The false
Engstrom began a vehement protest, but ceased suddenly, for, glancing
round, he saw Tegelmund also under guard.  The game was up!

A few minutes later, with Engstrom and Tegelmund safely in irons, the
Admiralty experts who had come over from London began a minute
examination of the wonderful "invention."  They soon discovered that the
cases contained a jumble of wires and odds and ends of mechanical scraps
simply thrown together to look complicated, and of no value whatever for
the renewal of vitiated air.

The real object was only revealed when we had got to the very heart of
the amazing collection of rubbish.  There, cunningly hidden among much
that was superfluous, was a highly efficient electric motor, wonderfully
made and controlling a powerful bomb by machinery, set to detonate the
explosive after six hours' running.  The machinery was to have been
operated by the electric batteries of the submarine, and had the E77
gone to sea and begun the "tests" of the bogus apparatus, not a vestige
of the vessel or the crew would have been seen again, and the secret of
her loss would have been locked for ever in the depths of the Atlantic.

But this, we found, was only a part of the plot--perhaps even the least
important part.  Tegelmund, finding himself trapped, turned craven and
revealed the whole story.  The real object of the spies was to get the
fullest possible details of the internal arrangements of a British
submarine of the latest type, and how well they had succeeded was shown
when we cast our net a little wider.

Directly Engstrom and Tegelmund were in custody, an innocent-looking
signal flag flew from the masthead of the submarine, and the officials
of the Surete ashore made their pounce.  Thornton and Halbmayr were
seized at once at their hotel, and in their possession we found a
wonderful series of drawings in which many of the secrets of the
submarine were fully explained.  A telegram to Paris brought about also
the arrest of Madame Bohman, and a few days later the German agents were
safely immured in the convict prison at Tours, where they were sent by
the sentence of a court-martial summoned immediately to deal with their
case.  Their guilt in this particular case was too clear for any
possibility of denial, but I am glad to say that their arrest opened up
a way to us to deal the Hun Secret Service a blow from which it has
never fully recovered.  Enormous piles of documents were seized and
carefully examined, with the result that numerous associates of Thornton
in England found themselves in durance vile "for the duration," and so
many fingers of the Hidden Hand were lopped off that the hand itself was
badly crippled for many months to come.  How the fingers grew and were
again cut off I hope to tell at some later date.

CHAPTER EIGHTEEN.

THE MYSTERIOUS CYLINDERS.

After over two years of strenuous work without a holiday I found myself
at length free, and I found myself one morning busy in my rooms in
Curzon Street making final arrangements for a trip to Worcestershire to
spend a fortnight with Doris and her mother in their lovely country
home.  I was jaded and fagged, for I do not mind confessing that my work
recently had considerably affected me, and I was looking forward with
eager anticipation to the delights of a stay in the country.  I had not
seen Doris for some months, though of course we were in constant
communication, and I was naturally longing for a sight of her.

But I was destined to another disappointment.  Just as I was finishing
my packing the telephone rang.  I found the call was from Morgan, one of
the ablest of the Government Experts on Explosives, and he had a curious
story to tell me.  When I had listened to what he had to say I realised
with a heavy heart that my long-promised holiday must be again
postponed.  I rang up Doris on the telephone and, having broken the news
to her, hurried off to Morgan's office.

I found the expert in a state of utter bewilderment.  He was an
acknowledged authority on explosives, but a problem had been set before
him which had baffled him completely.

A few days previously a mysterious explosion had occurred in some public
gardens at Mile End.  While a keeper was clearing away a pile of rubbish
he found a curious-looking metal cylinder lying in a flower-bed, and
while he was examining it it exploded with a tremendous report, injuring
the man so severely that he had to be taken, in a very critical
condition, to the East End Hospital.

A search by the police had a curious result.  In other flower-beds a
number of similar cylinders were found.  They were very tiny, being only
about an inch and a half in length and about a quarter of an inch in
diameter.  They contained a substance which was evidently the explosive.
At one end a piece of wire was attached, evidently as a means of
exploding them, and at the other end was a strip of soft lead.

Morgan showed me some of the cylinders, and frankly confessed his
ignorance of what they contained.

"I thought I knew every explosive in existence," he told me, "but this
is something entirely new.  It must be tremendously powerful, judging by
the size of the cylinders and the effect of the explosion on the
unfortunate gardener who found the first one."  As I held one of the
small cylinders, studying it with great care, an idea came to me.

"May I borrow this for a few days?"  I asked.  "I think I may be able to
help you."

"Certainly," replied Morgan; "but be careful.  We don't even know how it
is exploded."

Next day I was in Paris, and took train to Vemeuil l'Etang, some thirty
miles from the capital, where I called on the manager of a certain
well-known factory.

When I showed him the little cylinder he examined it with minute
attention and carefully withdrew some of the mysterious explosive.  This
he placed under a microscope and a moment later said:

"Monsieur is undoubtedly correct!  It is some of our product,
herbethite, the invention of our chief director, Mr Herbeth, and the
most powerful explosive known to modern science.  None has been used in
actual work yet, and the only sample that has left our factory is that
which was stolen.  It is a great secret."

"Has some been stolen, then?"  I asked quickly.

"Yes.  Fortunately we discovered the thief--a workman named Pasquet--and
we thought we had recovered all that had been taken.  Evidently we were
wrong and some of the stuff has got into bad hands.  Pasquet is awaiting
trial by the Assize Court of the Seine."

I returned to Paris and saw the Minister of Justice, to whom I made a
certain proposal.  Not without demur, he finally agreed, and I went to
the prison armed with authority for a private interview with Pasquet.

I met the thief in a small room in the governor's quarters of the
prison.  I found him to be a man of about thirty, quite obviously of the
hooligan type, and I soon guessed from his conversation that he had been
in the first place the tool of others, who, when they had made use of
him, had abandoned him to his fate.

He was naturally resentful and vindictive.  I told him I had authority
to offer him a free pardon, and a reward which would give him a decent
start in life if he would give us the fullest information in his power.
He was suspicious, however, and it was not until my promise had been
confirmed by the governor of the prison himself that he consented to
speak.

His promise once given, he made a clean breast of everything, and his
information was so startling that I could hardly credit it.  Possibly he
saw my incredulity, for he said quietly: "Monsieur will find that I am
telling the truth.  Why should I lie?  My whole life and liberty are in
pawn for my veracity."

I admitted that this was reasonable, and promised to, push things
forward as quickly as possible.  Something about the man had appealed to
me, and I wondered whether, after all, he might not contain the makings
of a decent citizen.

My first concern was to send a wire to Madame Gabrielle, who was in
Edinburgh, and the following evening she met me in my rooms in Curzon
Street, where I unfolded the whole story to her.

"Of course, we are not yet on firm ground," I pointed out to her.
"Pasquet alleges that the real name of his friend Shackleton is Von
Schack and that he is a Prussian engineer officer.

"Pasquet first met Shackleton in London, and later on Shackleton
approached him at Verneuil with another man, whom he introduced as
Norman, and they offered to buy some herbethite from him for three
thousand francs.  Pasquet told me that he was very hard up owing to his
wife's long illness--I have ascertained that this is quite true--and the
temptation proved too much for him.  It is only fair to him to remember
that, though he looks an abandoned ruffian, he bears a good character as
a husband and father, and it seems to be the fact that the only money he
spent out of that which he received from Shackleton and Norman went to
purchase necessities and delicacies for his wife.  The money really
seems to have saved her life.

"Anyhow, he stole a quantity of the herbethite, which Shackleton and
Norman packed in golden syrup tins and took to England.  When Pasquet
stole a second lot he was discovered, and the dangerous stuff was found
at his lodgings and recovered before he could hand it over to the two
men, who pretended to be English.

"One fact of importance at least is established," I added, "namely, that
Schack formerly carried on business as a watchmaker at Newcastle, and
sold his business to an Englishman a month before war broke out."

For weeks we hunted in vain for Shackleton.  I visited Newcastle, and
found that the man to whom he sold the business had later joined the
Army.  This meant a journey to France for me, and I had an interview
with the man at a certain brigade headquarters in the Somme battle area.

"Shackleton was undoubtedly a foreigner and I should say probably a
German," the watchmaker, now a corporal, told me.  "When he left he
asked me to forward any letters that might come for him, and gave me the
address--`Care of Soulsby, High Street, Bristol.'"

With that information I went straight from the British front to the
great Severn port.  Here I found that Soulsby kept a newsagent's shop
near Bristol Bridge, to which letters could be addressed.  He did a big
business in this way, for the address was very handy for sea-going men.

Soulsby at first refused to give me the smallest information about his
clients, but a sight of my authority opened his mouth, and as soon as he
realised that something serious was on foot he was only too willing to
help me.

"Of course, Mr Sant," he said, "you will understand I have no knowledge
whatever of the man.  But I know that the Bristol Channel ports are full
of spies, and it is very generally believed that few vessels leave here
unknown to the German submarines lurking about the mouth of the Channel.
If I can help you at all, I shall be delighted."

I then learned that Shackleton had called about a week before, taking
away several letters addressed to him, and that he usually called at
intervals of a week or ten days.  Soulsby promised to let me know at
once as soon as he came again, and I wired to the wily Aubert to come to
Bristol and keep observation.

Within three days, as I walked with my assistant along Victoria Street
towards Temple Meads, he pointed out a middle-aged, keen-eyed,
dark-haired man, who had little of the appearance of a Teuton.  He
looked like a well-dressed, prosperous business man.  Yet it was he who
had induced the unfortunate Pasquet to steal the herbethite, and he was
certainly engaged in some nefarious and deadly plot.  For although the
actual volume of the stolen explosive was not great, so tremendous was
its power that the quantity in the hands of our foes was sufficient to
wreak almost unimaginable havoc in half a dozen cities in England.  Mr
Herbeth had looked very grave when he learned from Pasquet through me
that the amount stolen was enough to fill two of the small cans used to
hold golden syrup--about a pint and a half altogether.

"I hope monsieur will trace it in time," he said earnestly.  "There is
enough of it in their possession to destroy half London."

We soon found out that Shackleton was living in furnished rooms at
Clifton and had one close friend, who, after some difficulty, we proved
to be his accomplice Norman.

One morning Aubert arrived at my hotel and reported that the pair had
gone to the station and taken tickets for London.  At once I advised
Madame Gabrielle by telephone to be on the platform at Paddington and
watch them wherever they went.  I myself took the next train to London,
and, driving to Curzon Street, awaited her report.

But although I sat up until after two o'clock the next morning, she did
not arrive and I received no word from her!  What contretemps had
occurred?  I was seriously uneasy, for I had impressed upon her the
vitally important nature of our task, and if she failed or met with any
mishap we should be in a serious predicament, for we had no trace
whatever of any of Shackleton's associations in London, and anything
might happen before we could run him to earth again among the teeming
millions of the metropolis, the safest hiding-place on earth.

It was not until six o'clock the next evening that I received, by
express messenger, a hastily scrawled note in which Madame Gabrielle
said:

  "Be extremely careful!  They have discovered me, and I am being
  watched, so cannot come near you.  Great things are in progress.  Get
  someone to watch Shackleton, who is at the address below.  Some great
  plot is in progress--that is certain.--G."

Without a moment's delay, I slipped round to Whitehall, and very soon an
expert watcher was at the address given by Madame.

Twelve hours later, I was filled with dismay by a telephone message
which told me that neither Shackleton nor Norman had been to the address
given.  They had both disappeared!

CHAPTER NINETEEN.

SPY'S LETTER DECIPHERED.

Back in Curzon Street, completely at a loss, I flung myself into a big
arm-chair, and over a succession of pipes tried to piece our
disconnected facts into a consecutive whole.  Shackleton, or Schack, had
moved from Newcastle to Bristol before the war, and I had little doubt
that he had done so by express orders from the Koniggratzer-strasse.
From this I argued mentally that Bristol would almost certainly be the
seat of his main activities, and that his early return thither might be
looked for with some degree of confidence.  Added to this, we knew from
the frank declaration of a high port official that the Bristol Channel
towns were swarming with spies, and I felt little doubt that they were
acting under Schack's direction.  On the whole, now that we had
apparently lost the two men in London, Bristol seemed the most promising
base for our operations.

I decided therefore to return, and, leaving Madame at the Grosvenor in
London, I took Aubert with me, together with an English secret agent
whom I will call Moore.

Moore took lodgings opposite Shackleton's house in Bristol and at once
opened an unwinking vigilance over the place.  For a fortnight, however,
there was no sign.  In the meantime two letters arrived, addressed to
Shackleton, at Soulsby's.  These were opened by the authorities,
photographed, and, after being resealed, were delivered in the ordinary
way.

In one of the letters, which had been posted in London and purported to
be an ordinary business transaction, was the statement:

"We are having great difficulty with our clients Johnson and Phillips,
so we have placed the matter in the hands of our solicitors for advice."

This letter ostensibly came from a firm of estate agents in the Harrow
Road.  I made an immediate inquiry, and was not altogether surprised to
learn that no such a firm existed.  In the meantime I studied the letter
on the assumption that it contained a spy cipher, and after some hours'
work succeeded in extracting from its apparently innocent contents the
following startling message:

"_Angorania_ will convey troops from Montreal on 30th proximo."

This set me at work with furious speed.  An inquiry at the port offices
showed me that the great liner was at the moment lying at Avonmouth, and
that she would sail for Montreal a week later in order to bring over
several thousand Canadian troops.

Shackleton now made what was to me, I confess, a very welcome return to
the scene.  I had been seriously perturbed by the fear that we had lost
him.  While he was under my own immediate observation I felt capable of
checkmating his designs, but the knowledge that an able enemy agent was
at large and uncontrolled, with enough herbethite in his possession to
create an appalling disaster, worried me more than I can tell.

Shackleton appeared on the scene the day after the delivery of the
letter we had intercepted and photographed.  Where he had been in the
interval we never learned, but he did not arrive in Bristol from London;
that was certain, for every train, day and night, was closely watched.
Evidently the letter meant a good deal to him.  He went at once to
Avonmouth, closely followed by Moore.  To our intense surprise, he
seemed very well known at the docks and was freely admitted everywhere.
He walked along the quays for some time, and we noted his obvious
interest in the _Angorania_, now busily getting ready for her coming
trip.  We learned later that Shackleton had very cleverly wound himself
into the confidence of a local shipping agent, and by this means had
secured such frequent admission to the docks that his presence there was
accepted almost as a matter of course.

I now began to feel practically certain that the _Angorania_ was the
object of the conspirators, and that the herbethite was the means to be
adopted to bring about her destruction.  But how?

Madame Gabrielle was to solve the question for us.  The great liner was
timed to leave at six o'clock, and an hour earlier the boat-train had
arrived from London, bringing an unusually large assembly of passengers.
These included several Government officials on their way to Canada, a
number of highly placed military officers, and the members of two or
three important war commissions.

Some time after the arrival of the train, a shabbily-dressed woman in a
battered old hat pushed rudely against me.  I turned, and to my
amazement recognised Madame Gabrielle.  She was obviously almost at the
end of her strength, pallid with fatigue, and with deep circles round
her eyes which spoke eloquently of exhaustion.

She made me a sign to follow her and slipped away from the crowd, which
was hastening to the gangway.  Directly we reached a quiet space, she
gasped out:

"Norman has booked cabin Number 189 on the _Angorania_, in the name of
Nash.  I followed him to the shipping office and overheard."  A moment
later she fainted and fell heavily into my arms.

I carried her at once to a waiting-room, and, handing her over without
ceremony to the woman in charge, dashed at top speed for the quay where
the _Angorania_ was lying, now almost ready for departure.  Not even for
the sake of Madame Gabrielle would I venture a moment's delay.

The "last bells" were ringing for the steamer's departure as I rushed on
to the quay.  As I neared the gangway I saw, to my utter amazement, the
man Norman stroll leisurely from the ship with the very last of the
people who had been on board for the customary farewells.  Evidently he
was not going by the vessel at all.  A moment later the gangways were
withdrawn and the big liner moved away.  Norman remained on the quay
with the crowd, idly waving a real or pretended farewell to some
supposed friend on the crowded decks.

I have cursed myself for my stupidity many times since, and even now I
shudder at the thought of how nearly the dastardly plot against the
liner came to success.  The vessel was well under way when the idea
flashed into my mind: "He has left the explosive on board!"  How I
failed to divine this earlier I cannot imagine.  I suppose Norman's
return from the ship threw me temporarily off my guard.

But, in any case, there was not a second to be lost.  The _Angorania_,
heading down Channel, was gathering speed every moment, bearing
somewhere on board enough explosives to sink her in ten seconds with the
loss of hundreds of precious lives.

Boldness was the only course possible.  I called a couple of dock
police, and, showing them my authority, instructed them to arrest Norman
at once.  Before the spy could recover from his surprise, he was safely
in custody and relieved of an extremely efficient automatic pistol.

And now for the _Angorania_.  I rushed to the "competent military
authority," and briefly laid the facts before a veteran Colonel, in whom
a life of splendid service to the Empire had bred a capacity for swift
decision and prompt action.

"She won't go far, Mr Sant," he said cheerily, as he picked up the
telephone.

A moment later I caught the crackle of wireless, and to my relief read
the message: "To Q.Q."  (the _Angorania's_ code letters).  "Heave to
immediately and await instructions.--Port Commandant."  A few minutes
later a clerk brought in the _Angorania's_ acknowledgment.

A quarter of an hour after I was aboard a British destroyer, which tore
out into the Channel, and at thirty-five knots was flying along in the
wake of the _Angorania_.  We soon overhauled the big liner, and as we
neared her could see the crowded passengers, evidently puzzled at the
unexpected stoppage.

As soon as I got on board, I accompanied the Captain to his private
cabin and told him the facts.  Sending for the purser, he ordered him to
bring on deck at once all the luggage which had come on board in the
name of Nash.  "And carry it carefully," he added, as he told the purser
what it contained.

By great good fortune, there was only one big trunk in the hold, and it
was readily accessible.  The rest of Nash's luggage was in his cabin.
We soon had the lot on board the destroyer, where the torpedo officer
rapidly overhauled it.

In the big trunk, resting quite unconcealed on the top of a pile of
clothes, were two tin canisters labelled "Golden Syrup."  I could not
repress a shudder.

"I think this is what we want," said the torpedo officer grimly, as he
carefully picked up the dangerous canisters.  And then he did a brave
thing.

"If you don't mind, sir," he said to the Captain, "I will take them out
in a boat and examine them myself."

The Captain nodded silently, and a few minutes later the ship's dinghy
dropped over the side.  The torpedo officer took his seat and rowed away
alone, the canisters on the after-thwart winking in the blazing
sunshine.  He was literally taking his life in his hands.  We could not
let the liner go until we were sure we had got what we wanted, and no
one could be sure that the mere lifting of the canister lids would not
explode the terrible compound they contained.

Half a mile away from the ship the rowing-boat came to a stop.  Through
our glasses we saw the torpedo officer deliberately pick up the
canisters and without hesitation prise up the patent lids.  A moment
later he waved to us, and at once commenced to row back to the ship.

"All right, let her go; I've got the stuff," he shouted, as soon as he
was within earshot, and a tremendous cheer went up from the crew, who in
the mysterious "wireless" of the sea had learned what was afoot.  A
signal fluttered from the bridge of the destroyer.  The _Angorania_
dipped her pennant in acknowledgment, and soon the great liner was
hurling herself through the sea on her interrupted journey.

The rest of the story is soon told.  The herbethite, we found, was
covered with a thin layer of sweets, and at the customs examination of
luggage Nash had boldly lifted the lids and coolly showed the sweets to
the officer.  It was done so naturally as to defy any possible
suspicion.  But in the bottoms of the tins we found two exquisitely made
detonators, fashioned in the shape of watches, and timed so as to
explode the herbethite some twelve hours after the time fixed for the
departure of the ship.  These removed, the tins could be handled with
comparative safety.

We made a clean sweep of the conspirators.  No details were ever given
to the public, and the stoppage of the big liner was easily explained
away to the passengers.  We found out that the small cylinder picked up
at Mile End had been intended for the purpose of blowing up a munitions
train in an important tunnel outside London, but the conspirators found
the approaches too closely guarded and gave up the project.  They were
all sent to Paris for trial on a charge of stealing herbethite, and were
eventually sentenced by court-martial to fifteen years' imprisonment.

Madame Gabrielle, I am glad to say, received a handsome reward from the
British Government, for our success was entirely due to her.  She had
followed Norman without food or rest or sleep for nearly three days, and
was in the last extremity of fatigue when she gave me her final and
all-important message.  Pasquet, I am glad to say, justified the
impression I had formed of him, and I had the satisfaction of seeing him
develop into a respectable member of society, happy in the society of
his wife, now fully restored to health, and again enjoying the
confidence of his employers.  We were able, through him, to account for
all the stolen herbethite, and it was a relief to know that none of the
terrible compound remained in the hands of our enemies.

CHAPTER TWENTY.

A MESSAGE FROM THE HERRENGASSE.

I have here put into narrative form a number of astonishing facts taken
from information read and testimony given at the court-martial
subsequently held upon the guilty parties.  The facts which I assisted
in establishing will, I believe, be found of considerable interest to
readers as further revealing the subtle methods of the enemy.

For obvious reasons I have been compelled to disguise certain names so
as not to bring eternal dishonour upon a great and noble family.

"And if I revealed the truth to your dear affectionate husband?"
whispered the soft-voiced, well-dressed Italian.  "What then--eh,
Elena?"

"_Madonna mia_!  No," cried the dark-haired, handsome young woman, who
sat at her tea-table in a great, elegantly furnished salon in one of
those old fourteenth-century _palazzi_ close to the port of Sarzana, the
Italian naval station on the Adriatic.

It was a bright afternoon in the summer of 1916; Sarzana, the old city
in Ferrara, to which I had gone with Madame Gabrielle, a lazy,
sun-blanched place, with its white houses and green sun-shutters, had of
late been electrified into naval activity against those hated Tedeschi,
those Austrians which every Italian had been taught to hate at his
mother's knee.

Things were going well with Italy.  On that day the _Corriere_ had
published a long dispatch from General Cadorna, reporting a smashing
defeat of the Austrians in the Alps, and an advance in the direction of
Trieste.  The whole kingdom of Italy, from Ravenna to Reggio, was in a
state of highest enthusiasm, and in Sarzana the excited populace were
agog in the cafes and in the narrow, old-world streets.

That most elegant fourteenth-century salon, with its faded tapestries
and fine old portraits, in which the woman was seated with her visitor,
was the same great room in which the Doge Francesco Bissolo, of Venice,
assembled the famous Council of Ten, when they consulted with Malatesta
after the Battle of Padua in 1405.  The Bissolo Palace, the dark, almost
prison-like walls of which rose sheer from the canal within a stone's
throw of the great naval dockyard, had little changed through five
centuries.  Its exterior was grim and forbidding, with windows barred
with iron, its massive doors, which opened upon the narrow mediaeval
street, heavily studded with nails and strengthened with iron.

Within, however, while most of its antique charm had been preserved, it
was the acme of luxury and taste, containing many priceless works of
art, magnificent tapestries, and the famous collection of ancient arms
belonging to its present owner, the Marchese Guilio Michelozzo-Alfani,
whose pretty young wife was that afternoon giving tea to a visitor.

"No!" the woman exclaimed, in a low, intense whisper.  "No, Carlo, you
would never do that.  I know that once I treated you badly, and I was
your enemy then.  But that is long ago.  To-day I am your friend.
Guilio must never know the truth.  In his position as Admiral of the
Port it would mean ruin for him if the truth were revealed that I am an
Austrian, and hence an enemy."

"Yes.  I agree that it would be very awkward for you, my dear Elena, if
the truth ever leaked out," remarked the thin, sallow-faced, middle-aged
man, as he sipped the cup of tea, in English fashion, which she had
handed him.  About his lips was a strange hardness, even though his
friendship was so apparent.

"But you alone know, my dear Carlo, and you will never give me away.  We
were old friends in Budapest--ah!  I wish to forget those days--before I
married Guilio," she remarked softly, with a bitter smile.

"My dear Elena, don't think that I've called to threaten you," exclaimed
Carlo Corradini, the well-dressed Italian, who lived such a gay
existence in Rome, and who was so well known in the cosmopolitan life of
the Corso and the Pincio.  "Why should I?  I am here, in Sarzana, upon a
secret mission--in order to speak with you."

"Why?"

"Well,"--as he paused he looked the young wife of the Italian Admiral
full in the face--"well, because, though your country is at war with
Italy to-day, Austria has still friends in Italy, just as Germany has."

"Ah!  This war is all so horrible," declared the Marchesa, with a slight
shudder.  "You Italians hate every Austrian with a fierce and deadly
hatred."

"Pardon me, my dear Elena, but you Austrians hate us just as fiercely,"
he laughed.  "Where is Guilio?"

"At his office.  He will not be back until seven.  He always goes to the
Club to take his vermouth there."

Corradini glanced at the door to make certain it was closed; then,
bending across the little table with its splendid silver service, he
whispered:

"I have a secret message for you--from somebody you know."

"A secret message--what?" asked the young Marchesa, opening her fine
eyes widely.

"From the Herrengasse, number seven."

"From Vienna?" she asked, in surprise, for the address he had given her
was the bureau of the Austro-Hungarian Council of Ministers.

He nodded mysteriously, and with a grin said:

"From your old friend Schreyer."

She drew a long breath and went pale for a second.  Mention of that name
recalled to her a remembrance of the past--of the days when she was a
dancer at the Raimund Theatre in Vienna, and when Count Schreyer had,
after a brief acquaintance, offered her his hand.  But she had disliked
him because he was such a cold, harsh bureaucrat, who had at that time
occupied a high position at the Ministry of the Interior, and who
possessed, as she once told a friend, "a heart of granite."

Elena's life-story had been a rather curious one, but, after all, not
much out of the commonplace.  The daughter of a poor Austrian musician
in the orchestra at the Weiner Burger Theatre, in Vienna, and of an
Italian mother, she had learned Italian from her birth, and on going to
Italy to fulfil an engagement at the Politeama, at Livorno, she had
posed as an Italian, though hitherto she had lived all her life in
Austria, and had been taught to hate her dead mother's race.

As an Italian, she had met, and afterwards married, the middle-aged
Marchese Michelozzo-Alfani, at that time a Vice-Admiral of the Fleet.
For three years prior to the war her life had been quiet and uneventful.
The summer she spent out at Antignano, on the seashore, three miles
from Livorno--or Leghorn, as the English call it--where they rented a
big white villa amid the vines and olives; in spring, on the Lake of
Garda; in autumn, in Florence; and winter, in Rome.

From his early days the Marchese had been a most popular naval officer,
who had fought in Abyssinia and in Tripoli, and, being a favourite at
the Court of the Quirinale, promotion had come to him rapidly.  Before
his marriage he had endeavoured to practise economy, in order to redeem
the fortunes of his ancient family; but now that his wife Elena proved
so extravagant, he found himself getting deeper into debt each day.

His appointment to Sarzana at the outbreak of the war had enabled him to
return to the ancestral palace, which had passed from the Bissolo family
to that of the Michelozzo in the sixteenth century, but which had for a
good number of years been closed and in the hands of caretakers.  His
was one of the most important naval commands in Italy, and the Austrians
were viewing that naval base with increased anxiety, it being so very
close to both Trieste and Fiume.  Admiral Michelozzo-Alfani was one of
the youngest of the officers of his grade in the Italian Navy.

Many raids he had made upon Austrian ports on the Adriatic, and Ragusa,
Zara, Sebenico and other places had suffered severe bombardment by his
"mosquito" fleet; therefore, at the Admiralty in Vienna his great
activity was being frequently discussed.

"I see, my dear Elena, you have not forgotten your friend the Count,"
laughed the sallow-faced Italian across the table presently.  "Neither
has he forgotten you."

"How do you know?"

"Well, because he spoke to me about you only three weeks ago."

"Three weeks ago!" echoed the Marchesa.  "How could you have met?"

Carlo Corradini grinned very mysteriously.

"Well--I was in Vienna three weeks ago--that is all."

"You in Vienna!" she gasped.  "Are you, then, a friend of my country?"
she asked, in a low, hoarse whisper.

"Why, of course," he replied.  "You are Austrian in all but name.  I am
a born Italian, but--well, I am a friend of Austria."

"A well-paid friend--eh?"

"Yes, just as you may be--if you will.  The Count is still your friend,
and he greatly admires you.  It is his one regret that you preferred the
Marchese Guilio.  He is a good fellow is the Count.  He is now prime
favourite with the Emperor, and he still remains unmarried.  Elena, he
thinks always of you, and only you."

The handsome Elena shrugged her shoulders.  The man who had called upon
her quite unexpectedly she had first met five years ago in Budapest.  He
was then a poor Italian composer of music.  Yet now, in mysterious
circumstances, he was, she knew, in possession of ample funds, and lived
in an elegant flat close to the Piazza Colonna in Rome.  They exchanged
glances, whereupon he settled himself to speak more openly to her, and
to give her a verbal message from her old admirer at the Herrengasse.

Carlo Corradini began by laughing at her patriotic devotion to her
husband's country.

"Of course Guilio is a most excellent fellow," he said.  "But, alas! he
is merely fighting a lost cause.  The Central Powers are bound to win,
and it is now for you to assist your own country.  Schreyer appeals to
you.  He knows of your difficulty in meeting that last loan which old
Levitski, the Jew, in Milan, made to you a year ago, and--"

"How does he know that?" she inquired, in quick surprise.

"My dear Elena, how does Austria know so many secrets of her enemies?"
he laughed.  "Schreyer is now head of that department of the Secret
Service which deals with affairs here in Italy, and--"

"And you, an Italian, are one of his agents," she interrupted, in a low,
meaning voice.

He bowed in the affirmative in silence.  Then, after a few moments, he
remarked, in a strange, meaning tone, his black, penetrating eyes fixed
upon her: "I know the secret of your nationality, and your friendship
with Count Schreyer--and you know mine.  So, my dear Elena, we have
nothing to fear from each other.  Do you understand?"

"I don't understand.  You surely are not hinting that I should betray my
husband's secrets--the naval secrets of Italy?"

The dark, smooth-tongued man from Rome smiled quietly, as he answered:

"That, my dear Elena, is exactly the message I bear to you from
Schreyer.  It is known that your husband tells you a good deal.  You
have whispered secrets to your friends, the Comtesse Landrini, and also
the Renata Pozzi.  If to them, then why not to me--eh?"

"Never!" she cried.  "I have married an Italian, and I am now Italian."

"But the money.  It will be useful.  Levitski must be paid in full in
eight weeks' time.  Seventy-two thousand lire.  That is the sum, I
think?  If you fail him this time, he will take his revenge and tell the
truth."

"He does not know."

"But Schreyer will tell him."

"What?" she gasped, starting from her chair.  "Has the Count told you
that?"

"Well, he has not exactly said so in words," was her visitor's reply.

"He only hinted at it, and sent me straight to see you.  I had to travel
by way of Holland and London--quite a long journey."

"Then you shall tell him that I refuse," she answered.  "I will never
betray Italy, and more especially through Guilio, who believes in my
patriotism, and never dreams that I am anything but an Italian born and
bred."

"That makes it all the easier.  He will never suspect you," remarked the
sallow-faced man, with a sinister smile upon his lips.

"I tell you," she cried angrily, "I decline to enter into it at all.
I--"

The door suddenly opened as she spoke, and there entered the Admiral, a
smart, good-looking, middle-aged man in uniform with decorations, whose
appearance was so unexpected that they both started.

"Decline what, my dear?" he asked sharply.  "What is the matter?"

"Oh, nothing, Guilio," she laughed lightly.  "You recollect Signor
Corradini, who used to come to see us in Livorno?"

"Why, of course," said the Admiral, as the two men bowed to each other.

A lie rose readily to her lips, and she said:

"Well, Signor Corradini has called in order to try and induce me to take
part in the Princess di Paliano's _tableaux vivants_ at Bologna, in aid
of the Croce-Rosso.  But I am far too busy with hospital work here in
Sarzana, so I have declined.

"Yes, dearest, you are far too busy.  I am always afraid Elena will
overwork herself, my dear Corradini.  I am nervous lest she should have
a breakdown."

The woman and her tempter exchanged meaning glances.

"Everyone knows how intensely patriotic is the Marchesa, and we all
admire her for her hard work in the cause of charity.  My friend the
Princess, however, asked me to call here and solicit her help, and in
consequence I have done so."

The Admiral thanked him warmly, for the Princess di Paliano's exertions
in war-work were well known throughout Italy.

Elena's husband sipped the tea she handed him, and, after chatting with
their visitor for a further half-hour, the Admiral suddenly asked:

"What are you doing down in Rome nowadays?"

"Oh, of course, we are all working hard.  I am secretary in a department
in the Ministry of War, the department which is in touch with France and
England concerning munitions."

He spoke the truth.  Carlo Corradini held a very important position in
the Ministry, even though, as we afterwards discovered, he had in secret
long been an enemy agent.  This latter fact, Guilio Michelozzo-Alfani
never dreamed.  Like all others, he never imagined that Carlo, hating
the Tedeschi so fiercely as he did, could be in secret their ingenious
and unscrupulous friend.

The Marchese himself was a true-born Italian, one of the ancient
aristocracy of the north.  Those who know Italy, know quite well the
stern and honest patriotism of her sons from count to contadino, and of
the fierce, relentless hatred of every Austrian.

Presently the well-dressed civilian functionary rose, clicked his heels,
and in the elegant Italian manner raised his hostess's hand, and,
kissing it, wished her _addio_.

The dark eyes of the Admiral's young wife met his in that second, and
they understood.

Five minutes later Carlo Corradini was hurrying along the Via Vittorio
Emanuele, the principal street in Sarzana, in the grey evening light;
then, turning to the left, he gained the Passeggio, which faced the
Adriatic, that long promenade lined with its dusty, wind-swept
tamarisks, where by day the _cicale_, harbinger of heat, chirped their
monotonous chant.

Corradini's visit to Sarzana proved to be a protracted one.  His excuse
was that he had been sent from the Ministry upon a special mission, and,
in consequence, he had preferred to rent a little flat on the Passeggio
than to live in the Albergo Stella d'Italia.  One day, at six o'clock,
he met, at a very obscure restaurant called The Vapore, a certain
Countess Malipiero, a middle-aged, ugly, but quite wealthy woman, who
lived near the Santa Maria della Salute, and who was a great personal
friend of the Marchesa.

The pair dined together at the popular little establishment, eating a
simple dish of _paste al pomidoro_, for which the _trattoria_ was noted,
a _costoletta_ and a piece of _stracchino_ to follow.  But over that
simple meal the pair remained in serious consultation, while not far
from them sat the good-looking but unobtrusive Madame Gabrielle Soyez,
for the pair were already under suspicion, though we had as yet no
reliable evidence to justify interference.  Afterwards the pair walked
together as far as the Piazza Grande, and there parted, the spy of
Austria smiling as he went along the noisy street towards the sea.

CHAPTER TWENTY ONE.

THE ADMIRAL'S SECRET.

Three weeks passed.

Old Sarzana has ever been a city of black conspiracy and clever
intrigue.  In those glorious days of the Venetian Republic persons of
both sexes who were antagonistic, or in any way obstacles to the
carrying-out of the secret plans of the Council of Ten, were "by
accident" secretly poisoned or openly "assassinated," as is shown in the
many reports which even to-day repose in the secret archives of the
Palace of the Doges at Venice.  As mediaeval Sarzana was a veritable
hot-bed of intrigue in those days when Venice ruled the Adriatic, so
were desperate plots afoot in the yesterday of Cadorna's triumphant
advance into Austria.  Enemy plots and counter-plots were hatched in
those darkened houses upon the silent waterways, or by the open sea.
One of them I now reveal for the first time.

Truth to tell, the Marchesa Elena had been forced, by the elegant,
insidious Corradini, to accept traitorous service in the pay of Austria.
Their usual meeting-place was in the old church of St Antonio, which
at vespers was always crowded by the devout, who, in the days of war,
prayed for Italy's victory.  Sarzana had always been one of the most
pious cities in Italy, and each evening the splendid old Cathedral was
crowded.  And in that crowd the pair met--kneeling side by side to
whisper, and again near them knelt Madame Gabrielle.

In all Sarzana no woman worked harder at the great war-hospital
established in the Communal Palace than the popular wife of the Admiral
of the Port.

The Marchese, the most influential and delightful man in Sarzana, was,
as everyone knew, the author of the many raids upon the enemy which had
from time to time been carried out.  Well known, too, it was, how the
"mosquito" fleet of destroyers, piloted by him, had only a month ago
entered the great harbour of Cattaro, opposite Rimini, and had sunk four
big Austrian battleships at anchor there--four of the biggest ships of
Austria's navy.

About this time the wealthy Countess Malipiero--who was nowadays Elena's
most intimate friend, and who was constantly at the Admiral's table--
purchased a big sea-going motor-launch, a quiet, harmless old fisherman
called Beppo, well known in Sarzana, being placed as skipper.  Before
the war, the Countess had, in secret, been in very poor circumstances,
but owing to the death of a relative--so she explained--she had been
left a substantial legacy.

One evening, as the Admiral and his wife were about to finish dinner
_tete-a-tete_, the manservant announced that Captain Vivarini, the
second in command, had called and desired to speak with his chief very
urgently.

"Show the Captain to the study," said the Marchese, as he rose at once
and passed along to his cosy little den which overlooked the port.

Elena, instantly upon the alert, and suspecting that something unusual
had happened, waited until the Captain had been conducted to her
husband's room, and then she crept silently along to the door, where she
knew she could overhear the conversation, having listened there several
times before.

On tiptoe she approached noiselessly over the soft Turkey carpet, and,
placing her ear to the door, was enabled to hear news.

In brief, it was to the effect that one of the newest Austrian
submarines had been captured intact, with officers and crew, off the
Point of Cortellazo.

"The submarine Number 117 left Fiume only yesterday, according to its
commander, whom I have interrogated," the Captain reported.

"_Benissimo_!" exclaimed the Admiral, much gratified.  "Then the enemy
will not yet know of its capture.  In the meantime we must act.  The
submarine belongs to Fiume, therefore, my dear Vivarini, she must return
to Fiume."

"Go back?" echoed the Captain.

"Yes.  She must sail again to-night with an Italian crew," said the
Admiral.  "She will enter Fiume harbour flying her own flag, but at the
same time she will discharge torpedoes at as many of the vessels of war
lying there as she can.  You understand?"

"_Santa Vergine_!  What a plan," exclaimed the Captain enthusiastically.
"Most excellent, Signor Marchese."

"All must be done in strictest secrecy," said the other, lowering his
voice.  "Not a single word must leak out, for there can be no doubt that
there are spies here in Sarzana.  News of our intentions gets across the
Adriatic in an astounding manner sometimes.  Not a syllable must be
known, either regarding our capture or our intentions.  Number 117 must
return to-night."

"Not a whisper," the Captain agreed, whereupon the Marchesa, a tall,
slim figure in a dinner-gown of carnation pink, and wearing a velvet bow
of the same shade in her hair, slipped back again to the salon, where
she awaited her husband, pretending to read.

"Well, Captain Vivarini," she exclaimed, greeting their visitor merrily
as the two men entered.  "Some new development, I suppose, eh?"

"Yes, Marchesa," replied the handsome naval captain, bowing low over her
hand with that peculiar Italian courtesy.  "A little confidential
matter," and he laughed.  Then, after a cigarette and a tiny glass of
green certosa, the Admiral and the chief of his staff left.

As soon as they had gone, Elena rushed to her room, slipped off her
dining-gown, and, putting on a tweed skirt and blouse, hurried from the
house.

She slipped along the dark, narrow side street, until suddenly she
emerged on to the moonlit promenade, and ascended the dimly lit stone
stairs which led to the room occupied by Carlo Corradini.  In response
to her ring, the spy of Austria at once admitted her.

"Why, Elena!  This is a surprise.  What has happened?" he asked eagerly.

The Admiral's wife passed into the little sitting-room, and, without
seating herself, revealed hastily what was intended, adding: "I must
return home at once or Guilio may wonder where I am."

"What a plot!" exclaimed the dark-haired traitor.  "It does the greatest
credit to your husband's ingenuity."  Then, suddenly reflecting, he said
in a strange, hard voice: "If I act successfully your husband himself
may be charged with giving away secrets to the enemy.  If so, because
you love him, you might denounce me, Elena."  After a second's pause, he
added: "I trust no one.  Not even you.  My life is at stake in this
affair.  Therefore, you will swear that, whatever happens, and even if
suspicion be cast upon your husband, you will never betray me?"

"Of course, Carlo.  Am I not Austrian?  I swear it."

The spy took from a table a book covered with shiny black leather, and
pressed it very firmly into her hand.  It was a copy of the New
Testament.

"Kiss it--and swear," he said.

In obedience, she acted as he wished, repeating a solemn oath after him.

"I trust you, Elena," he said fervently, at the same time gallantly
kissing the back of the white, slim hand which had held the book.

"And I trust you, Carlo," she whispered.  "Trust in me.  No suspicion
must rest upon anybody.  I leave that to your own clever ingenuity."

A few moments later she descended the steep stone stairs to hurry home
as quickly as she could.  Arriving at the great _palazzo_, she at once
resumed her smart dinner-gown, and, entering the salon half an hour
afterwards, sat down to await her husband's return.

Ere she had done this, however, the motor-launch of the Countess
Malipiero, driven by old Beppo, sped out from the harbour on pretence of
taking an invitation to one of the lieutenants on board the battleship
_Italia_, which was lying just within the Mole.

He slowed up alongside one of the guardships by the boom, and as he did
so the great eye of a searchlight was turned full upon him.  Then, at
once recognised by the watchman on duty, he was allowed to pass out to
sea.  Being such a familiar figure, no suspicion had ever been cast upon
the stern, patriotic old fellow.

Sometimes his boat was stopped and examined, but, as he never had
anything aboard, it had become a habit with the guardships to allow him
to pass unchallenged.

When about a mile from the boom, the old fellow drew a map from his
pocket, and, having examined it very carefully by the light of a
flash-lamp, consulted his compass.  Then, altering his course, he sped
along for nearly two hours in the darkening night, when at last he
placed two green lights, one at port and one at bow.

He had started at ten, but it was nearly one o'clock in the morning when
he began to grow anxious and consult his watch.

Presently he saw the slight tremor of a searchlight, and, fearing
detection by some Italian ship, he at once extinguished all his lights,
and, pulling up, waited for nearly half an hour.  It was a dark, lonely
vigil, but, with the aid of another cigar, the crafty old seafarer
passed the time until he again ventured to relight his green lamps.

Scarcely had he done this when, about half a mile away, he saw a tiny
light winking in the Morse code.  He read the familiar signal, and,
cutting off his engine, waited until, of a sudden, the low hull of a
submarine came up in the darkness, quite close to him.  Then, adroitly
manoeuvring his launch, both the vessel and boat rising and falling in
the heavy swell, he drew nearer.

"Is that Beppo?" shouted a voice in Italian from the submarine.  "Yes,"
shouted the old man.  "I have something for you."  He took from his
pocket a small leather bag-purse, such as men carry, one of those drawn
through a ring, tied it upon a tight line, and, standing up, he flung it
with a seaman's precision over the conning-tower of the submarine.

"All right," shouted the Austrian officer, for such he was.  "Wait a
moment till I've read what you have brought."

For a few moments he disappeared into the body of the vessel, while
Beppo hauled in his wet line.  Then, when the officer reappeared, he
shouted:

"All right, Beppo.  No answer.  _Buona notte e buon viaggio_."  That
same evening a secret council had been held, presided over by the
Admiral, when all the details were arranged.  The officers and crew of
the Austrian submarine Number 117 were safely under lock and key, and
after the council, just before eleven o'clock, the Admiral himself
visited the captured undersea boat, and inspected it.  Commander
Bellini, one of Italy's most distinguished submarine officers, had been
chosen, together with a picked crew, to attempt the raid, but none were
informed, for the Marchese was determined this time to keep the secret
of his plans.

Just before midnight a submarine, heavily awash, for the sea was rough,
slipped away out of the harbour of Sarzana, winked a farewell message,
and then, submerging so as not to be seen by other ships, was lost to
view.

She was the raider, the intention of whose commander was to blow up, or
damage seriously, at least half a dozen of the enemy's ships lying off
Fiume, on the other shore of the Adriatic.

The Italian crew consisted of a picked lot of fine patriotic fellows,
who only now knew their desperate mission, and they knew also what their
fate must be--either death or capture, when the truth became revealed.

After travelling swiftly all night, the periscope revealed at dawn the
long, broken Austrian coast.  Then, when within five miles of the
entrance to the deep bay of Quarnero, at the end of which is situated
Austria's important harbour, the vessel emerged and ran up her Austrian
colours.  Before her, high upon the green point of Monte Grosso, which
guards the entrance to the bay, a signal was made, to which Number 117
replied, and then, with her grey hull showing above the surface, she
sped unsuspiciously up the channel, past the small wooded islands, and
the pretty town of Abbazia, into the harbour, where lay fully a dozen
war vessels, including three of the enemy's biggest battleships.

Suddenly, however, just as she was about to discharge a torpedo at a
battleship flying the Admiral's flag, the thunder of guns rang out from
all sides, and Number 117 became the target for concentrated fire from
all the forts.

As the shells hit her she flew to pieces.  Next second she was seen to
be rapidly sinking with all on board, not a soul being able to escape
from that rain of death.

The submarine had been entrapped, and the raid had ignominiously failed.

News of the disaster reached Admiral Michelozzo-Alfani through the Naval
Intelligence Department in the afternoon, and he sat in his room
astounded.  So well kept had been his secret that he felt absolutely
positive that, outside those officers who formed his Council, nobody had
any knowledge of his intention.  All of those officers were men above
suspicion.

That there was a traitor somewhere he was more fully convinced than
ever.  Other minor secrets had been known to the enemy mysteriously from
time to time, yet he had been utterly unable to trace the source of the
leakage.  Alone in his office at the port, he sat at his table, his brow
resting upon his hands.

At noon, unknown to him, his wife had telephoned to the Countess
Malipiero, but was informed by the latter's maid that she had left
hurriedly for Rome on the previous night, after a visit from her friend,
Signor Corradini.

Throughout the afternoon she expected Carlo to call upon her, and became
extremely anxious when he did not put in an appearance.

At last, unable to stand the strain longer, she sent her little
sewing-maid round to Corradini's flat, but the girl returned with the
letter to say that, according to the _donna di casa_, the signor had
left Sarzana hurriedly at ten o'clock the previous night.

The hours seemed like years as the guilty woman sat alone in her
magnificent, old-world salon, pale, startled, and nervous.  Upon her
left hand she wore a white glove.  She had worn it ever since the
previous evening, and the reason had greatly perturbed her.

At last, at nearly ten o'clock that night, her husband returned,
hard-faced and haggard.  With him was his chief of staff, Captain
Vivarini, Madame Gabrielle, and myself.  The instant we entered the room
she saw that Guilio was not his old self.

"Elena," he said abruptly, in a deep, hard voice, "I have something to
say to you, and I have brought Vivarini here as witness."

"As witness," she echoed, starting to her feet.  "Of what?"

"As witness that you are innocent of the charge made against you, that
you, though my wife, are a spy of Austria."

"A spy," she laughed uneasily, in pretence of ridicule.  "Have you
really taken leave of your senses, Guilio?"

"I have not.  Tell me," he demanded, "why are you wearing that glove?"

I saw that she held her breath.  Her face was instantly blanched to the
lips.

"Because last night I scratched my hand," she replied.

"Please remove it, and allow me to see the scratch."

"I refuse," she cried angrily.

Next instant, at a sign from the Marchese, Vivarini and I seized her
hand, when her husband, roughly tearing off the white kid glove,
examined her palm.

He stood aghast.

"_Dio_!" gasped the horrified man.  "The brand is here.  You, Elena, my
wife, you are the spy."

"Guilio," shrieked the unhappy woman, flinging herself frantically upon
her knees before him.  "Forgive me.  _Santa Madonna_!  Forgive me!"

"I may forgive you, Elena," replied the Admiral, in a low, stern voice,
"but Italy will never forgive."

Then, turning abruptly, he left the room, the Captain following.  But as
he passed out two agents of the Italian secret police passed in, and a
few seconds later the wretched woman found herself under arrest.

It was not until her trial by court-martial, in Milan, two weeks later,
that the Marchesa learned, from the evidence given by Madame Gabrielle
and myself, the truth of Carlo Corradini's terrible vengeance--a
long-nurtured grievance that he had held against her ever since those
days in Budapest, when, on proposing to her, she had laughed him to
scorn, and had actually told people of his poverty.  He had sworn to be
avenged, and truly his vengeance had been both ingenious and complete.

On the evening when she had brought to his room the information
regarding the captured submarine he had handed her the Testament upon
which to take her oath of secrecy.  Upon the shiny black leather cover
of that book he had traced with a solution of nitrate of silver, mixed
with other chemicals, a geometrical design--a square divided in half,
the lower part being left blank, and in the upper portion a "V", above
it being traced a small circle.

When he had placed the book into her palm it had left an indelible
imprint upon her skin, a device which did not show itself until an hour
later, when, very naturally, it greatly mystified her.  Carlo Corradini
had thus branded the woman he hated, and then, the coup having been made
at Fiume, he had at once written an anonymous letter to Armand Hecq,
head of the International Intelligence Bureau, denouncing the Admiral's
wife as an Austrian, who had divulged Italy's secret.

In support of his allegation, he urged us to search the rooms of Carlo
Corradini, where we should not only find evidence of espionage, but also
the actual Testament by which the hand of the Marchesa had been branded.
Further, that eighty thousand lire would be found in her possession,
that being the price which Corradini had paid for the information
concerning submarine Number 117.

The trial, held in camera, opened at eleven o'clock, and just before
three sentence of death was pronounced.  An hour later I was present
when a firing party was drawn up in the yard of the great San Giovanni
prison.  Her eyes were bandaged, and the capital sentence was carried
out.

Truly, Carlo Corradini was a scoundrel of the worst type, and his
revenge was, indeed, a dastardly one.  Fortunately, however, it
reflected upon himself, for, four months later, he and his companion,
the Countess, were captured, living in obscurity in a small coast
village near Bari, in the extreme south of Italy, where they were hoping
to escape to Greece.

Corradini's own anonymous letter proved the most direct evidence against
him, and ultimately both paid the same penalty as their victim, in the
yard of the Prison of San Giovanni at Milan.

------------------------------------------------------------------------

The End.






End of Project Gutenberg's Sant of the Secret Service, by William Le Queux

*** 