"We've had Sprout's, that was the Devil's Snare; Flitwick must've put charms on the keys; McGonagall transfigured the chessmen to make them alive; that leaves Quirrell's spell, and Uncle Sev." Draco stopped suddenly, they had reached another door. Taking a deep breath they pushed the door open together. A disgusting smell filled their nostrils, making both of them pull their robes up over their noses. Eyes watering, they saw, flat on the floor in front of them, a troll lay sleeping. The massive creature was drooling and snoring, Harry swore the floor was moving with every breath.