At Hogwarts, the Slytherin group is untouchable — feared by students, hated by professors, and loyal only to each other. But when students begin disappearing and strange things start waking beneath the castle, the group is pulled into something far darker than school rivalries and pureblood politics. Ancient secrets. Forbidden magic. Betrayals hidden for generations. And somehow, Y/N Blackheart is at the center of all of it. As the danger grows, so does her connection to Mattheo Riddle — reckless, dangerous, and hiding secrets that could destroy them both. But in a castle where nobody can be trusted and something monstrous is waiting below, falling in love might be the deadliest mistake of all.