"Why do you wear that form all the time, anyway?" Nathaniel asks, almost challengingly though it's supposed to be a peace offering.

Bartimaeus remembers the boy who trusted him, whom he trusted, whose faith in cooperation between magicians and demons inspired his own; remembers his death, and the death of his vision with him. This boy, who can't bring himself to trust even after all they've been through, wouldn't understand, and Bartimaeus doesn't bother trying to explain.