In Amityville, New York, a general contractor named Charles Humes, Ken Van Sant, is facing execution after killing his wife and two daughters with a hammer. The day before the sentence is carried out, he meets with Father Benna, Jeff Kirkendall, and opens up about a disturbing belief: the killings were driven by demons he claims reside within lumber he took from 112 Ocean Avenue, a house that had been haunted until an exorcism performed by Benna’s brother, Father Jonas, ended with Father Jonas’s death. The traumatic memory of Jonas’s death continues to haunt Benna. Charles reveals that the tainted wood was later used in his own home and in other properties, and he hands Benna a list of those affected.
Among the properties on that list is a house inhabited by Amy Dukane, Marie DeLorenzo, and her abusive alcoholic father, Jeremy. Jeremy is described as a widower after his wife Bonnie, Bonnie Dukane Kathryn Sue Young, dies in a drunk-driving crash caused by Jeremy. As the story unfolds, both Amy and Benna begin to experience terror from a demon that seems to corrupt the house’s wood, and that demon drives a burglar to a grisly fate, disemboweling him before infusing Amy with a cluster of demons known as Legion.
Amy’s affliction intensifies during a night walk in the woods, where she and the demon are implied to be responsible for the death of a photographer, who is killed under the demon’s influence. Meanwhile, Jeremy becomes a target of the haunting as Benna visits him at his home, and Jeremy remains skeptical about the claimed haunting until Amy torments him with visions of Bonnie. The tension escalates when Amy murders her boyfriend, Robby, while Benna is blessing the residence. After this, Amy’s strength wanes, and Benna and Jeremy restrain her to a bed, hoping the exorcism can take effect.
As the exorcism begins in earnest, Amy’s restraints are tested when she summons the demon that implanted her with Legion. The demon taunts Father Benna, who responds by drawing a bloody cross on the demon—a cross that is created from a wound Benna bears. The dramatic moment culminates as the cross seems to banish the demon and Legion back to Hell, freeing Amy from their hold.
With Amy freed from the possession, she and Jeremy begin to repair their fractured relationship, while Father Benna prepares to confront the wider problem: the remaining properties that were tainted by 112 Ocean Avenue’s cursed wood, now scattered across the area. The fates of the other houses and their occupants linger as Benna heads out to continue the work of countering the lingering curse.
