i need a train to leave from cambridge after 15:30 .
user
ok , lets get you set up , where are you going and on what day ?
assistant
i will be leaving on saturday and going to london liverpool street .
user
i would recommend tr4859 which leaves cambridge at 15:59 and arrives at london liverpool street at 17:27 .
assistant
that sounds fine . can you reserve 6 tickets for me please ?