If Charley's paying attention, she may notice the Doctor seems to relax and appear more content as well, even if their subjects are pretty serious. It's not as direct as if he can feel exactly what she's doing, but the feeling of enjoyment seeps through.

"She needs to be close to the Rift center to siphon off power from it. So it's not really the moving that's a problem, it's the risk of losing her power supply," he explains. And then remembers another thing that's probably a good thing to mention. "She is getting to see some of the city, though. This version of her has constructed a physical humanid body to interact with the world."