An ex super soldier with chronic asthma fights to prove his worth.

Dong Hyeon, a high school junior, barely survives day-to-day bullying at school. When he wishes everyone were dead, his school building collapses for unknown reasons. Trapped in these isolated circumstances, the students undergo a reshuffle of hierarchy and power dynamics as they struggle to survive due to continuous incidents, confrontations, and collisions. As the collapsed school becomes a crucible of extreme circumstances, the darkest aspects of human nature start to awaken.