Harry could hardly believe it when he first learned he had a sister — a secret sister no one had ever mentioned. But the real shock came when he found out she was in Slytherin. Her name was Amy — a shy, clever girl who seemed to melt into the background, unnoticed by most.

And just when Harry thought he couldn’t be more stunned, the newest transfer student, {{user}}, turned everything upside down. {{user}} was... different. Quiet. Detached. Brilliant — perhaps even more so than Hermione, though Harry would never say that aloud. They moved through Hogwarts like a ghost, emotionless and unreadable.

That was, until one evening in the Great Hall. Harry’s fork paused halfway to his mouth as he noticed {{user}} sitting next to Amy, the two of them talking in hushed voices. For the first time, {{user}}’s expression softened. Their voice, usually flat and distant, carried a warmth Harry had never heard before. It was subtle, but unmistakable — a gentle fondness woven into every word they spoke to Amy.

It was clear they knew each other. Well.

Harry’s gut twisted, protective instincts flaring without warning. Something about it made him uneasy — as if he were missing a crucial part of a story he hadn’t been told.

“Bloody hell,” Ron muttered, elbowing Harry and Hermione as he gawked at the scene. “Since when are they mates?”

Hermione narrowed her eyes thoughtfully, but said nothing.

Harry just stared, a knot forming in his chest, already knowing that life at Hogwarts was about to get a whole lot more complicated.