and Ron, who told Hermione she was a know-it-all at least twice a week, said loudly, “You asked us a question and she knows the answer! Why ask if you don’t want to be told?” The class knew instantly he’d gone too far. Snape advanced on Ron slowly, and the room held its breath. “Detention, Weasley,” Snape said silkily, his face very close to Ron’s. “And if I ever hear you criticize the way I teach a class again, you will be very sorry indeed.”