During a tense Potions lesson at Hogwarts, Y/N Potter finds herself partnered with Mattheo Riddle, the notorious Slytherin whose sharp tongue and mysterious nature make him impossible to ignore. As they work together brewing a volatile potion, their usual rivalry simmers beneath every exchange, challenged by an undeniable curiosity neither wants to admit. Mattheo’s cold façade begins to crack as he pays more attention to Y/N than he intends, while Harry Potter watches from across the classroom, increasingly suspicious of the growing connection between his sister and the son of a dark legacy. Surrounded by jealousy, secrets, and the pressure of their family names, Mattheo and Y/N are forced to navigate the fine line between enemies and something far more dangerous.