You've got the book tucked under your arm. Advanced Potion-Making. Heavy, leather-bound, the cover warm from your grip. Mattheo had shoved it at you in the Great Hall two days ago, muttered something about needing it back.

His exact words: "Don't read it. Don't lose it. Just bring it back."

You'd rolled your eyes then. Roll them now, too, as you push open the heavy oak door to the sixth-year boys' dormitory without knocking. The password — Pureblood — had slipped from a first-year's mouth in the common room, and you'd used it without a second thought.

The door swings inward.

The room is dim. Curtains drawn around the four-poster beds, the embers in the fireplace glowing low and red. The air smells of ash, old parchment, and something metallic.

And there he is.

He doesn't look up.