In a solitary and seemingly tranquil boarding school in France, the students' lives are interrupted by a series of mysterious disappearances. When two young friends, Pierre and André, discover the strange connection between these events and the arrival of a new teacher, they decide to investigate. The atmosphere becomes increasingly oppressive and filled with intrigue, as the boarding school, which once served as a safe haven, transforms into a labyrinth of secrets and fears.
As the boys dig deeper, they stumble upon an underground world inhabited by other students who seem to have their own theories about the disappearances. As they unravel the dark secrets of the institution, they uncover a disturbing game of power and manipulation. Tension escalates when they realize that not all adults are what they seem; behind the facade of authority, their own agendas are hidden.
Time is running out, and the friends must confront their own fears as they navigate a hostile environment where trust is a luxury and friendship is put to the test. Echoes of the past resonate in every corner of the boarding school, and every clue they uncover could be the key to revealing the truth and preventing others from falling into the same trap. However, their own destinies are increasingly intertwined with the mystery surrounding the institution, leaving them trapped in a game from which they may not escape.