A group of ambitious medical students seeks to uncover the mysteries of life after death by conducting dangerous experiments. They are led by Nelson, a daring student who convinces others to temporarily stop his heart, allowing him to experience clinical death before being resuscitated. His peers, intrigued by the potential discovery, agree to help. Following Nelson's initial experiment, the other students—Joe, David, and Rachel—each take their turn to flatline, aiming to explore the realm beyond life for increasing durations. After each experience, they are brought back with defibrillator paddles, documenting their visions and insights post-resuscitation.

As the experiments become more frequent and the durations of flatlining longer, the students begin to experience troubling side effects. Their personal lives become haunted by visions, and each faces unresolved issues from their pasts manifesting in disturbing ways, challenging their sense of reality. The consequences of crossing the line between life and death loom over them as they struggle to understand if what they are experiencing is real or hallucinatory. Driven by curiosity and haunted by what they've awakened, they grapple with moral and ethical boundaries and the potential ramifications of their quest for knowledge.