so when it all became. . . too much. . . I could transform in my cell. . . become a dog. Dementors can't see, you know. . . " He swallowed. "They feel their way toward people by feeding off their emotions. . . They could tell that my feelings were less -- less human, less complex when I was a dog. . . but they thought, of course, that I was losing my mind like everyone else in there, so it didn't trouble them.

Chapter 19