"Students training to use their powers," she says in answer to his unspoken question. "A demonstration, not a real lesson, but it's always fun to see the students let loose a little."

It's usually the most entertaining part of the day, the part that gets the children excited and the parents either excited or anxious. Whether Childermass will appreciate it... Well, she doesn't know. What exactly does he want to get out of this visit? No idea.