You snap your wand up and fire the stunning spell before Snape can speak another word. A red burst strikes him square in the chest, and his body jerks backward into the shadows with a sharp crack of robes against stone. The cursed command shatters at once, and the room seems to exhale in startled silence. For a second, only the blue flames and your racing heartbeat remain, while the trapdoor below gives a slow, grinding shiver.

Quirrell lies bound and pale on the floor, staring at you in terrified disbelief, while the book on the table stirs with a weak, sickly glow. The chalk circle around the candles flickers as though it is losing its shape, and dust sifts down from the beams in a fine gray curtain. Whatever was being held beneath Hogwarts is still there, but the pressure has eased just enough for you to act. You tighten your grip on your wand and look between the unconscious Snape, the sealed trapdoor, and the trembling book, knowing the next choice may decide everything.