For a moment, Eric considers ignoring Humpty. He sees a future in which he stubbornly sits down and continues on with the tour. But they both know he won't. He doesn't want to be around these people who are likely judging his every movement now, and he doesn't want to lose sight of Humpty.

So he follows and gets off the bus with Humpty. He looks around to get his bearings, but he's still too new to the city to have any idea where they are.

It's easier just to focus on Humpty, to not be caught off guard if he tries something.