"Your cabin number." It's said with an air of obviously, despite the fact that that's not really why he wants to see Adam's ticket. He slides his own across the table in return. "There's thirty five of them, I'm not about to go running up and down the sleeper cars trying to find you."

It's never actually occurred to Ronan to try and duplicate one of the tickets, mostly because he's never had a reason to want someone else's ticket. Technically, he probably could have gotten close enough by using his ticket as the base and simply changing who the ticket was for, but holding things is always the fastest way to commit them to memory for him. He can reproduce things from his own imaginings and he can produce things from cobbling together other things, but to replicate things he needs to have held them himself.