Naalai Manithan

In 2008, Dr. Shankar develops a drug that can resurrect the dead if injected within two hours of death. He works with Ramesh and Kanth in a Chennai laboratory. They successfully revive a dead man named John, setting off a chain of unforeseen consequences.

The revived John is granted immortality by the drug, but the revival triggers murderous side effects. He cannot die from injuries, and his actions become increasingly violent. The town begins to feel the presence of an unstoppable killer.

With his immortality, John begins murdering people in the town, spreading fear as the killings continue. The police struggle to understand how a revived body operates and why it seems invincible. The city is gripped by a chilling series of murders.

John murders a group of youngsters at a resort, drawing the attention of the police. Officer Vijay and deputy Shekar corner him, and he is arrested after a brutal confrontation. The capture marks the first clash between the revived killer and law enforcement.

John breaks out of handcuffs, overpowers the officers, and sustains severe injuries. He is transported to the hospital for treatment. The escape signals that containment may be impossible for someone who cannot die.

Kanth asks Shankar to kill John, deeming him a societal threat. John overhears the plan, escapes from the institute, and heads toward Kanth's home. The pursuit shows John actively seeking places to hide and further his plans.

John infiltrates Kanth's home and engages Kanth in a brutal fight. Despite being shot multiple times and knocked down stairs, Kanth dies. Shree, Kanth's wife, returns home and is killed by John.

Preethi arrives for her upcoming marriage to Vijay and discovers the corpses of Kanth and Shree. Realizing the danger, Preethi escapes as Vijay arrives to investigate. The sequence deepens the terror around the revived killer.

Shekar takes Preethi to the institute, unaware that John has already returned there to seek treatment for his wounds. The institute becomes a focal point of the renewed chase and danger. Preethi's safety becomes a priority for Vijay and his team.

Ramesh attempts to kill John by injecting him with acid, but John survives due to immortality and retaliates. Shankar, who comes to cure John, is killed in the resulting chaos. The brutal killings escalate further within the institute.

John chases Preethi through the institute while Shekar tries to shield her. John defeats Shekar, removing another of Vijay's allies and intensifying the pursuit. The danger to Preethi grows more imminent.

Vijay returns in time and shoots John, causing him to fall off a balcony. Preethi is rescued as the immediate threat seems to be temporarily contained. John's apparent defeat ignites a new resolve to finish him off.

John revives again and clings to Vijay's car, forcing a deadly chase. The vehicle crashes and explodes, lighting John on fire. He jumps into a nearby lake to recover, where he shows alarming resilience.

In the climactic confrontation, Vijay defeats John by striking him and throwing him into a well. Believed dead, John resurfaces from the well, leaving the town with a chilling implication that the killer may still be alive.