You had the compartment to yourself, a rare luxury on the first day back. Your trunk sat overhead, your wand tucked safely in your robes, and a half-read book resting on your lap. The train had been quiet so far—most of your friends had found their own compartments, reuniting after a long summer apart.

A burst of laughter echoed from somewhere down the corridor. Muffled voices, the scrape of a compartment door sliding open, then shut. The train swayed gently, and the afternoon light slanted through the window, catching the dust motes floating lazily in the air.