During World War II, while serving in the Solomon Islands, Marine Willard Russell finds the barely alive Gunnery Sergeant Miller Jones skinned and crucified by the Japanese. Willard ends Jones' agony by shooting him in the head. After the war, on his way home to Coal Creek, West Virginia, Willard passes through Meade, Ohio, where he meets Charlotte, a waitress at a diner. Willard and Charlotte marry and move to Knockemstiff, Ohio, where they have a child named Arvin.In 1950, Helen Hatton marries the bizarre yet charismatic evangelical preacher Roy Laferty, who pours venomous spiders over his head in one sermon to demonstrate his faith in God. Helen has a child named Lenora. Roy has a severe allergic reaction to a spider bite, affecting his grip on reality. Believing that he has the ability to resurrect the dead, Roy stabs and kills Helen, but fails to see her revive. Roy realizes his error and flees to return to his daughter.Roy hitchhikes and gets picked up by a pair of married serial killers, Carl Henderson and his wife Sandy. Their serial fetish homicide ritual involves picking up male hitchhikers, encouraging them to have sex with Sandy while Carl takes photographs, and then murdering them. Roy refuses to have sex with Sandy, and Carl shoots him dead.In 1957, Charlotte is diagnosed with cancer. Willard believes he can influence God with fervent prayer to remove cancer from his wife's body. He prays to God and sacrifices the family dog, kneeling before a rustic cross he had erected in the woods behind his house. However, Charlotte dies of her illness, and Willard soon commits suicide. Arvin, now orphaned, goes to live with his grandmother Emma, where he meets Lenora, who has been adopted as his stepsister.In 1965, Arvin is given his father's Luger pistol as a birthday present. The church has a new preacher, Reverend Preston Teagarden, who also exhibits fanatical behavior. After noticing Lenora being repeatedly harassed by bullies at school, Arvin confronts and savagely beats them. Meanwhile, Preston takes advantage of Lenora's loneliness and rapes her. Lenora soon informs Preston of her pregnancy, who blames her for the incident and turns her away. Not wanting to bring shame to the family, Lenora prepares to hang herself. As she stands on a bucket, she changes her mind and tries to remove the noose, but accidentally slips off the bucket and dies. Arvin is told that she was pregnant following her autopsy, and immediately suspects that Preston was the father. He spies on Preston, then confronts him at the church and kills him with the Luger.Arvin hitchhikes and gets picked up by Carl and Sandy. When Carl starts his homicide ritual with Arvin, Arvin defends himself, killing Carl and Sandy with the Luger. In the car's glove box, Arvin finds a collection consisting of several rolls of film. Sandy's brother, Sheriff Lee Bodecker, learns about Sandy's murder, and to protect himself and his coming reelection, goes to Carl and Sandy's apartment, where he finds and destroys Carl's photo collection.Arvin goes to Meade to visit his childhood home. Lee learns that Arvin murdered Preston, and heads to Meade in search of Arvin. They both confront each other in the woods at the location of Willard's rustic cross; Lee with a shotgun and Arvin with the Luger. Shots are exchanged, but Arvin mortally wounds Lee. Arvin confronts Lee with the picture of Sandy with Roy's dead body as Lee bleeds out and dies, then leaves the photo and rolls of film with Lee's corpse.Arvin hitchhikes again and gets picked up by a hippie driving a VW van. The film ends with him daydreaming and contemplating his future as possibly a husband or as a soldier in the Vietnam War.