Thirty years ago, serial killer Chris Fuchman raped and murdered ten fathers, an atrocity that landed him a release on a technicality and set a curse in motion. In the decade that followed, more fathers were raped and slain, yet no evidence tied these crimes to Fuchman, leaving the situation mired in uncertainty. One victim turns out to be the father of siblings Ahab, Adam Brooks, and Chelsea, who are torn apart by the violence around them. Ahab is sent to live with the local priest, Father O'Flynn, Kevin Anderson, while Chelsea stays on her own path. Ahab eventually tracks Fuchman down to the scene of his latest crime—the murder of another father named Bill Cummings—and is caught and arrested by Detective Stegel, Brent Neale. He is tried, found guilty on everything except Cummings’s murder, and sentenced to ten years in prison.
Father O'Flynn urges Father John Sullivan, Matthew Kennedy, to locate Ahab and bring him to talk sense into him. John finds Ahab living alone in a hut; at first Ahab refuses to speak with O'Flynn, but he eventually agrees so he can reconnect with Chelsea, trading a mutual bond for a dangerous potion he had brewed. They return to the church, where O'Flynn advises Ahab to search Andrew’s house for clues. Ahab uncovers more than he expected: Stegel reveals that Chelsea works at a strip club called the Lowlife, and Ahab makes his way to the club, where he encounters the manager, Sleazy Mary, Meredith Sweeney, an old flame from his past.
Chelsea invites her friends Andrew (also known as Twink) Conor Sweeney and Walnut Garrett Hnatiuk to her apartment. When the lights go out, Walnut is killed by Fuchman after he admits he may have accidentally gotten a girl pregnant from a one-night stand. Twink narrowly escapes death, but Chelsea fires at Fuchman, scaring him away. Fuchman flees as Ahab arrives to speak with Chelsea again. Ahab and Twink meet for the first time and decide to join forces to kill Fuchman, but Stegel arrives to question Chelsea, threatening to derail their plans. Chelsea agrees to help Ahab and Twink escape on the condition that they meet her at the Lowlife so she can join the fight against Fuchman. They agree, though Ahab insists that Chelsea stay out of the mission.
That night, Father O'Flynn is murdered by Fuchman, and John joins Ahab and Twink on their mission. They track Fuchman using Chelsea’s notebook about him, and Ahab finally kills Fuchman after finding Chelsea gravely injured. John then goes to tidy Father O'Flynn’s room and discovers an ancient tome—an occult document that reveals Chris Fuchman is a manifestation of a demon known as the Fuchmanicus, protected by a Satanist cult. The book explains that a Fuchman appears in each generation to rape, murder, and feast on the souls of fathers, and when a Fuchman dies, the Fuchmanicus possesses a woman to birth a anew Fuchman. It prophesies a man resembling Ahab who will bring forth “the most powerful Fuchman ever.”
As Chelsea, now possessed by Fuchman, arrives at Ahab’s room and seduces him, the siblings’ encounters grow increasingly intimate, culminating in an implied creation of a Fuchman born of incest. The Satanist cult is revealed to include Stegel and Mark, who launch an attack on Ahab’s apartment. John and Twink arrive just in time to help, tearing into the cult and denouncing Ahab for allowing himself to be seduced by his sister. They discover Fuchman has taken Chelsea back to Hell with him. In a desperate move, Ahab, John, and Twink choose to sacrifice themselves to travel to Hell and rescue Chelsea.
In the infernal realm, John reaches Heaven and abducts an angel to force access to Hell, while Twink is killed by a demon who uses Walnut (and their unconsummated love) as bait and decapitates him. Ahab locates the Fuchmanicus’ lair, where Chelsea is chained while Stegel and Mark stand as guards. The trio’s fight ends badly for many: Mark and Stegel are crushed, John is torn in half, and Mary appears to hurl a jar of syrup at the Fuchmanicus. The demon turns Fuchman into a baby and is then stomped to death by Chelsea.
Mary attempts to reconcile with Ahab, but Chelsea’s love for her brother is too strong to ignore, and Mary’s advances are rejected. Chelsea’s soul returns to Earth, and the devil is revealed to be God. As Chelsea fades, John begs her to consider an abortion to eliminate the potential Fuchman growing within her. With her soul in limbo, Mary, Ahab, and John remain in Hell, left to contemplate escape. John suggests they simply hope, but a final cut to the living world reveals the grisly truth: Twink, Ahab, and John have rotted away, eaten by a pair of cats, leaving Chelsea as the sole survivor and casting doubt on any path to escape.
In the end, the film weaves a stark tapestry of horror, guilt, and the idea that some cycles may be impossible to break. The emotional weight of broken families, the lure of ancient evils, and the blurred lines between salvation and damnation coalesce into a story that lingers long after the credits. The supernatural undertow—the Fuchmanicus myth, the Satanist cult, and the monstrous lineage—provides a chilling frame for the bleak, unflinching mood that dominates the narrative, while the frantic actions of Ahab, Chelsea, John, Twink, and the others push the plot through a relentless chain of confrontations, revelations, and losses.
