Harry Potter faces a boggart that doesn't turn into a Dementor or even Voldermort, but into a horror from his childhood. Now the boggart isn't even a boggart anymore. There's no imitation. That which holds the image of an Angel, becomes itself an Angel.

John is struck with a memory from his teenage years. / / "You drew this," John grins, pointing to the little drawing on the paper. "You gave it to me when you were five. I babysat you."