Oh bloody hell. Of course it was Peeves. And of course that little bastard would lock him in with that shrew. She was battering at the door, and that was clearly having no effect. Blaise doubted that something as simple as knocking it down would work. Peeves might be demented, but he wasn't careless.
He wandered over to where Johnson was sputtering. He thought he could see a vein standing out on her neck. "What exactly do you suggest?" he asked. "You've been very thorough." The poltergeist had said something about figuring out a secret. He assumed it was going to be some kind of puzzle.