Jack, a failed architect from Washington State, recounts how he became a serial killer to Virgil—whom he refers to as Verge—as Verge leads Jack through the nine circles of Hell. Each of Jack's crimes, depicted through flashback, feature social commentary from Jack and Verge.
In the first incident, Jack encounters an abrasive woman on a rural road who needs to fix her broken jack to repair a flat tire. He agrees to take her to a blacksmith. She irritates Jack, saying he looks like a serial killer, insulting him, and then stating he is too much of a wimp to kill anyone. Offended, Jack bludgeons her with the tire jack and stores her body in an industrial freezer inside a factory building he purchased from a pizzeria.
In the second incident, Jack murders a widow, Claire. Instead of leaving, his obsessive-compulsive disorder compels him to return to re-clean the crime scene multiple times, resulting in him nearly being caught. He ties Claire's body to the back of the van in a panic and drives off, dragging her body behind and creating a blood trail leading back to the factory building. However, it starts raining, washing away the trail, and Jack takes this as divine intervention. He declares himself "Mr. Sophistication" and begins signing anonymous letters to the media with this moniker. He begins taking greater risks as his OCD diminishes.
In the third incident, Jack brings his girlfriend and her two sons, "Grumpy" and George, on a hunting trip. He kills both sons with a rifle before forcing the woman to have a picnic with their corpses. He allows the mother to run, but she allows herself to be shot by Jack. Jack fashions Grumpy's corpse into a sculpture with a grisly smile.
In the fourth incident, Jack is in a dysfunctional relationship with a woman, Jacqueline, whom he psychologically and verbally abuses and derisively nicknames "Simple." When he drunkenly confesses to her at her apartment that he has killed 60 people, she does not believe him. After he marks red circles around her breasts with a marker, she becomes frightened and approaches a policeman, but he dismisses her and Jack as drunk. Jack later binds her before cutting off her breasts with a knife. He pins one of the breasts to the policeman's car and fashions the other into a wallet.
In the fifth incident, Jack has detained six men in his freezer, intending to kill all of them with a single bullet. One of the men, an army veteran, informs Jack that he has the wrong ammunition. He goes to get the right ammunition from a friend, SP. SP phones the police, since they're looking for Jack, who then stabs SP through the throat. Jack kills the responding officer and returns to his freezer. He unseals a second chamber inside, where he meets Verge, who has been observing Jack throughout his life. Verge reminds Jack that he never built the home he intended to, as he had made several attempts to build his perfect house between his murders. In the freezer, he arranges the frozen corpses he has collected over the years into the shape of a house. As police break in, he enters his "house" and follows Verge into a hole in the floor, entering Hell.
The two reach a pit leading to the ninth circle and centre of Hell. Footage is shown about the Kola Superdeep Borehole, in which, according to legend, human cries from the underworld were heard. A broken bridge spans the pit. Jack notices a stairway on the other side, which leads the way out of Hell. Jack attempts to scale a rock wall to access the staircase, against Verge's advice, and falls into the flaming abyss below.
