Can you help me get train tickets leaving london kings cross arriving by 18:30?
What day would you like to travel?
On Thursday please. 
TR5219 is leaving London Kings Cross at 05:17 and arriving by 06:08 at cambridge on friday
Can you tell me the price and travel time of that?
I'm sorry about the misinformation. The TR2775 leaves on Thursday like you want. The price is 23.60 and the travel time is 51 minutes. 
Thank you. I am also looking for a place to eat, called graffiti. 
I have that, what would you like to know and would you like to book it?
I would like to make a booking for 1 people at 21:00 on the same day.
I'm sorry, they were not able to accommodate that request. Would you like to try a different time?
How about 20:00 instead? 
I'm sorry, but that booking is also unavailable.  Is there a different day or time I can check for you?  Maybe earlier in the evening?
If 21:00 and 20:00 are not available, I guess I am not interested in booking anything.  Can you check one more time for 20:00?
It was still unsuccessful. I am sorry. Any other times you would like me  to check?
No, unfortunately I need either 21:00 or 20:00. Thank you for checking.
I tried again, but there may be some technical difficulty.None of the reservations I've tried are working. I tried for every time between your requests. Can I help with anything else?
No, but I appreciate the help.
I hope you have a lovely day.
Thanks so much, but I just realized I am missing a crucial bit of info. What is the departure time on my train, please? The corrected train, that is.
I don't believe we were able to complete a reservation. Would you like to try again?
Yes, a train to Cambridge from london kings cross on Thursday by 18:30. If you can get a table for 1 at Graffiti that day at 20:00 or 21:00 too, great.
Booking was successful, the total fee is 47.2 GBP payable at the station .
Reference number is : R8P7XT7B.
That's all I need. Thanks.
OK. I'm sorry I wasn't able to get you into the restaurant you wanted. Your train TR2512 is leaving at 13:17. Let me know if you ever need anything else.