"It's a visual sense," he says. "Well, partly. Mostly. One is... as though everything in my field of vision comes with little labels saying what the distances are between any part and any other part, and the other is orientation relative to known landmarks. But—" he starts to make a gesture, discovers that Cam is still holding his hand, goes very suddenly very pink, and continues after a short pause without continuing to gesture "—I don't orient relative to where something is, I orient relative to where I remember it. I can always find where we parked the car, but if somebody moves the car I can't immediately tell where they put it. If someone teleported my house three feet backward, I'd notice the next time I looked out the window or went outside, but I don't think I'd be able to tell right away. I haven't actually experimented with teleporting, come to think of it."