Yes, that's Broxbourne to Cambridge on Thursday, leaving after 17:45.
When would you like to arrive?
Sorry. I really need to be leaving from Cambridge to go to Broxbourne, leaving after 17:45 on Thursday. Arrival time doesn't matter.
How about TR9890? It departs Cambridge at 18:01 and arrives in Broxbourne at 19:01. It is 17.90 pounds per ticket. Would you like to book that one?