In an attempt to help someone close, two high schoolers end up inside a deeply hidden underground school. Instantly cut off and completely disoriented, only one of them remains a main active player across six sub-floors of silent chaos. In this space, an isolated, anomalous phenomenon interacts with human psychology, weaponizing it into deadly bio-physical threats. To survive this tragedy and find a way out, he must quickly adapt, calculate his every move, and rely on pure strategy.