Plot

A priest battles a demon that kills sinners in the act of sinning.

In New Orleans, a series of horrific murders of priests are occurring around the city's Catholic churches. The diocese calls in Father Michael (Cross) to fight the powerful demon, known as Daesidarius, or The Unholy. The Father's faith is tested almost to the breaking point as the demon - disguised as a stunningly beautiful lady - attempts to seduce Father Michael into breaking his vows. Father Michael soon learns how the Unholy works - by murdering the sinner in the act of sinning, then sending that person's soul to Hell. Will this one priest's inner strength be enough to stop this monster - or will he join the ranks of the other ill-fated priests?—medic249a2

While praying in St. Agnes church in New Orleans, Father Dennis is confronted by a demon taking the shape of a seductive woman. The woman tears his throat open, killing him. Several years later at a New Orleans hotel, Father Michael is called to talk to a man named Claude who is threatening to jump from the top floor of the building. When he offers Claude a cigarette, Michael is pulled out the window and falls to the ground. Inexplicably, he survives the fall without injury. After the incident, Michael is appointed to the St. Agnes parish by the Archbishop Mosely; the parish had been closed after Father Dennis's unsolved murder.

Upon moving into the rectory, Michael is notified by Lieutenant Stern that another priest was murdered there before Father Dennis. Michael finds mention of Millie, a waitress at the Threshold, a local black magic performance art club, in Dennis's journal; Michael goes to visit her, but she is evasive. She later comes to the parish, claiming to Michael that she saw Father Dennis for confession before his death; during the confession, she admitted to giving her soul to Luke, the owner of the club, whom she claims is the Devil incarnate. Luke visits Michael shortly after, claiming that the Satanic shows put on at the club are only gimmicks, and that he does not actually believe in them; however, he says he's been recently experiencing supernatural phenomena and begs for Michael's help. Michael agrees to spend an evening in Luke's apartment, where he witnesses furious poltergeist activity.

When Michael brings the information to Archbishop Mosely, he is informed that Father Dennis was approached by Millie and Luke in an identical manner before being murdered. Father Silva, an elderly blind demonologist, informs Michael he has been "chosen" to fight the devil, but Michael dismisses the notion. Millie is incarcerated in a psychiatric ward after attempting to kill Luke, and Michael goes to visit her. In a fit of madness, she claims Luke tried to rape her, and that Father Dennis has been talking to her. That night, Michael has a nightmare of the Demon, and receives a disturbing phone call from Father Dennis, who claims he is "waiting for him in hell." Millie arrives in the middle of the night begging for help, and Michael agrees to let her stay in the rectory.

While cleaning the church with the housekeeper Teresa, Millie is fascinated by a statue of the Immaculate Heart of Mary, which Teresa tells her was salvaged from a church in a foreign country that burned down. Lieutenant Stern warns Archbishop Mosely that Michael is in danger, suspecting Millie was responsible for the previous murders of the St. Agnes priests; Mosely assures him that Michael is safe. Meanwhile, Millie discovers a book in which she reads of a demon known as the Unholy, which seeks to corrupt and then take pure souls. To prevent herself from being a target, she propositions Michael to take her virginity, which he refuses. Convinced Luke planted the book, Michael confronts him, but Luke denies it.

The next day, Michael finds Luke's eviscerated corpse hanging above the church altar in the pose of the Cross of Saint Peter. Seated in a pew is Claude, who begs Michael's forgiveness for pulling him out the window. Suddenly, Claude begins to bleed profusely from his eyes and mouth, and bursts into flames at the foot of the Immaculate Heart of Mary statue; Luke's corpse also ignites. Michael meets with the Archbishop and Father Silva, who warns him that the Unholy will manifest to Michael between Ash Wednesday and Easter, when it will try to tempt and then kill him. In the church, Michael is confronted by the Unhholy (taking form as the woman), and she attempts to seduce him, but he denies her.

The Unholy reveals its true form-a monstrous creature-and two mutant creatures crucify Michael. Millie enters the church and is confronted by the creature, but before it can harm her, Michael calls upon God for strength, and damns the Unholy to hell. He collapses, and when he awakens, is blind. As Millie walks him out of the church, the Immaculate Heart of Mary statue begins to weep tears of blood.