I Am Not a Serial Killer

John Wayne Cleaver, a teenager in a small Midwestern town, is a diagnosed sociopath and has a morbid obsession with death and serial killers. He works at his mother April's funeral home as a part-time assistant mortician. He controls his homicidal urges with strict rules, mental stopgaps, and sessions with his therapist Grant. At the scene of a murder, John sees a puddle of black oil. An identical murder sparks rumors of a serial killer, which piques John's interest. While out trick-or-treating with his friend Max, John spots a drifter lurking outside his neighbor Bill Crowley's house. At the high school Halloween dance, John scares off a bully by threatening to kill him. John sees the drifter join Crowley on an ice fishing trip, and follows them. Out in the water, as the drifter is about to attack Crowley, Crowley kills the man with his bare hand, which morphs into a branch-like shape. Crowley cuts out his own lungs and replaces them with the man's. John creates a serial killer profile, noting every victim had organs removed. John follows Crowley and his wife Kay on their date night. As Crowley was limping because of a weak leg, a local barber named Greg invites Kay for a dance. John comes across his mother and Grant having dinner, which upsets him. John later researches fairytales and mystic folklore. The police connect the recent murders to a missing person named Emmett Openshaw. John follows Crowley to Greg's barbershop and sees Crowley attack Greg. John impulsively sets off the barbershop's alarm, drawing two police officers, whom Crowley kills. Crowley leaves the barbershop, appearing to be rejuvenated and without a limp. John sees a puddle of black oil at the scene and realizes it was Crowley's old leg, which he replaced with Greg's. After leaving Crowley an anonymous note revealing his knowledge, John overhears Kay saying Crowley has been housebound for a week. As John visits Crowley at Kay's request, Crowley recites and explains William Blake's poems "The Lamb" and "The Tyger". John continues to profile Crowley, who grows weaker. On Christmas Eve, John calls Crowley from a pay phone to ask about the process and what he stole from Openshaw. Crowley gives vague answers, and John realizes Crowley was stalling. Seeing Crowley's car, John flees to Max's house. After admitting their friendship was merely a coping mechanism, John is thrown out. John stumbles upon Crowley killing Max's father; John, wearing a ski mask, fails to stop Crowley and flees. After Max's father's memorial, April tries to connect with John, who threatens her life when she pushes him. After a conversation with Grant, John waits until Crowley leaves the house and tries to scare him away by threatening what he loves most: Kay. When John believes he has unintentionally killed Kay, he panics and calls Grant. After seeing she is still alive, John leaves the house as Crowley arrives. In Crowley's car, he finds Grant's intact body, which he hides. The next morning, Crowley realizes John has taken the body. At Max's father's funeral, Crowley reveals Grant had been out looking for John. John says Crowley will not try anything in public and observes that Crowley's heart will not last much longer. After the funeral, John realizes his mother did not leave; he finds her unconscious on the embalming table beside Crowley, who demands John return Grant's body. John pretends to agree but knocks out Crowley. After April regains consciousness, they hook Crowley up to the embalming device. When Crowley wakes, the lights flicker, and a large, black, oily monster slides out of his body. Realizing he can no longer be with Kay, he asks John to watch over her and commits suicide. Both Crowley and the monster's corpses melt into black oil. The police find Grant's body, and Crowley is reported missing. John comforts Kay, who tells him the story of how she and Crowley fell in love, making John realize he can find happiness, too. John and his mother later have a conversation as they embalm Grant's body.