Adam (Leigh Whannell) wakes up and finds himself trapped in an abandoned toilet. Opposite him is Lawrence (Cary Elwes) who has the same fate. They are tied to their legs with iron chains and are surprised to find a terrifying dead man lying between them. The dead man is bleeding, holding a recorder in his left hand and a gun in his right hand. A tape is put into Adam's pocket, and he quickly puts it into the recorder. The tape says that Lawrence must kill Adam before 6 o'clock tonight, otherwise they will die together, and Lawrence's family will not be spared. The blood flowing from the dead man in front of him is extremely poisonous. A bloody death game begins. In the short time left, they must find clues and escape from hell. At the last moment, when they thought they would see the light of day again, a new round of nightmares has just begun.