I want to book a train. I would like to depart from cambridge and arrive by 16:45
What is your destination?
The train should depart from cambridge and should arrive by 16:45. Going to Ely
What day will you be travelling?
I would like to go on Saturday.
How about TR8860?
Sure, I would like to book that train for 4 passengers. 
Booking was successful, the total fee is 14.08 GBP payable at the station. Reference number is : VX48ZGH0.
That's wonderful. I am all set. Thank you. Goodbye.
You're very welcome! Goodbye.