AKA "Harry Potter and the Prisoner of Azkaban"
Chapter 1 (Harry's homework from A History of Magic):
"Non-magic people (more commonly known as Muggles) were particularly afraid of magic in medieval times, but not very good at recognizing it. On the rare occasion that they did catch a real witch or wizard, burning had no effect whatsoever. The witch or wizard would perform a basic Flame Freezing Charm and then pretend to shriek with pain while enjoying a gentle, tickling sensation. Indeed, Wendelin the Weird enjoyed being burned so much that she allowed herself to be caught no less than forty-seven times in various disguises."
Chapter 2 (Uncle Vernon to Harry)
"We told Marge you attend St. Brutus's Secure Center for Incurably Criminal Boys."
Chapter 5 (Professor Dumbledore):
"Well, I am sorry to tell you that Professor Kettleburn, our Care of Magical Creatures teacher, retired at the end of last year in order to enjoy more time with his remaining limbs."
Chapter 22 (Professor Dumbledore):
"You think the dead we loved ever truly leave us? You think that we don't recall them more clearly than ever in times of great trouble? Your father is alive in you, Harry, and shows himself most plainly when you have need of him."