For four marginalized teenagers, their summer detention involves the task of tidying up their high school following a dreadful event. However, they soon discover they are not alone; a sinister group, disguised as The Four Horsemen of the Apocalypse – Famine, Pestilence, War, and Death – has trapped them inside and is pursuing them through the school’s devastated corridors. As these students fight for their lives, they are forced to face the haunting remnants of past traumas they have tried to bury, with the risk of being doomed to experience them all over again.