Nefarious

Dr. James Martin arrives to evaluate Edward Wayne Brady at the state penitentiary. Warden Moss warns him that Brady is a master manipulator who can get inside your head, and that Martin must determine whether Brady is legally sane or insane for the upcoming execution. Brady is scheduled to be executed at 11:00 that night.

In their initial discussion, Edward details his life and insists he is a demon named Nefariamus inhabiting his body. He claims he will be executed and that Nefarious will answer to him, revealing his belief in possessing the host. He also states that he will commit three murders before the day ends, challenging the doctor's certainty.

Nefarious accuses Martin of euthanizing his terminally ill mother to gain inheritance; Martin defends his decision, insisting the action was based on careful examination. The exchange heightens tension and frames medical ethics as a battleground for moral judgment.

Martin suspects Edward suffers from dissociative identity disorder and tries to speak directly with Edward, but Nefarious frequently dominates the host. Through the alternating voices, the doctor explores the role of demons in the world while maintaining his atheistic stance.

Nefarious exposes Martin's private life, claiming his girlfriend is at an abortion clinic. Martin rushes to call her, only to learn that the abortion has already taken place. The revelation shakes his clinical distance and personal boundaries.

Nefarious proposes that Martin become the author of The Dark Gospel, a Satanic book meant to deceive humanity, and claims to have known Martin since childhood. He offers to grant Martin power and knowledge if he accepts the arrangement.

A scrapbook of Martin's life and the manuscript for The Dark Gospel are found in Brady's cell, forcing a confrontational moment as the doctor confronts the implications of Brady's schemes.

Brady dislocates digits, escapes his handcuffs, and begins to strangle Martin. The doctor, fearing for his life, pretends to beg for mercy to buy time, and guards eventually subdue the killer.

Brady is forcibly restrained, and Martin signs a document stating that Brady is sane enough to be executed. Nefarious declares that Martin has committed three murders: the mother, the unborn child, and the prisoner.

Edward is executed by electric chair at 11:00 PM. In the final moments, Nefarious takes control and asks Martin whether he will accept the devil's offer to publish the Gospel; Martin refuses. Edward dies in a prolonged, painful death.

In the aftermath, the demon possessing Edward seems to shift to Martin as he holds a gun and attempts suicide. The weapon misfires, and Martin instinctively calls on God for help, suggesting a spiritual struggle continues.

A year later, Martin appears on a television studio promoting his novel, A Nefarious Plot, presenting it as a warning about demonic temptations. He acknowledges a perceived miracle that the gun misfired during the attempted possession and remains curious about God while identifying as agnostic. A homeless woman who may now be the host of Nefarious approaches him after the interview.

In a post-credits audio, the voice of Nefarious speaks in Latin, claiming that Martin has been weighed in the balance and found wanting, and hints that the story will continue.