Chapter 8: The Hufflepuff Girl and the Missing Memories

The singing stopped at half past two in the morning.

Holmes noted the cessation as he would have noted any sudden absence—with the automatic attention of a man trained to register when a background condition changes. He was still at his writing table, the casebook closed but within reach, the lamp burned low, when the sound that replaced the singing reached him through two floors of stone and the particular acoustic peculiarity of Hogwarts' northeast stairwell: not quite a scream, and not quite not one. The sort of sound, he thought, rising from his chair before he had consciously decided to, that a person makes when they have stopped understanding what they are looking at.

He had the lamp and the casebook in hand before the second sound reached him. He was at the door before the third.