"I'd take that gum out of the keyhole if I were you, Peeves," he said pleasantly. Peeves paid no attention to Professor Lupin's words, except to blow a loud wet raspberry. Professor Lupin gave a small sigh and took out his wand. "This is a useful little spell," he told the class over his shoulder. "Please watch closely." He raised the wand to shoulder height, said, " !" and pointed it at Peeves. With the force of a bullet, the wad of chewing gum shot out of the keyhole and straight down Peeves's left nostril; he whirled upright and zoomed away, cursing. "Cool, sir!" said Dean Thomas in amazement. "Thank you, Dean," said Professor Lupin, putting his wand away again. "Shall we proceed?"