Rolfe Whitehouse begins the film by recounting Wade Whitehouse, Nick Nolte, a small-town policeman in New Hampshire, and his alleged "strange criminal behavior" along with his disappearance. On Halloween night, Wade meets his daughter Jill, but he is late and the evening is shadowed by disharmony. Jill calls her mother, Wade's ex-wife, to come and pick her up. When she arrives, Wade shoves her husband against their car and watches them drive away with Jill. Wade vows to hire a lawyer to gain custody of his daughter.
The next day, Wade rushes to the scene of a crime. Jack Hewitt, a local hunting guide, claims that Evan Twombley, with whom he was hunting, accidentally shot and killed himself. The police side with Jack, but Wade grows suspicious, convinced that Twombley was killed by Jack. When he learns that Twombley was scheduled to testify in a lawsuit, his suspicion slowly hardens into conviction.
A while later, Wade and his girlfriend Margie Fogg, Sissy Spacek, arrive at the house of Wade's alcoholic father, Glen Whitehouse, whose abusive treatment of Wade and Rolfe as children is revealed in flashbacks throughout the film. Wade finds his mother lying dead in her bed from hypothermia. Glen reacts to her death with little surprise, and later gets drunk at her wake and gets into a fight with Wade.
Rolfe, who has come home for the funeral, initially suggests Wade's murder theory could be correct, but later renounces himself from the presumption. Nonetheless, Wade becomes obsessed with the conviction. When Wade learns that town Selectman Gordon Lariviere is buying up property all over town with help from a wealthy land developer named Mel Gordon, also Twombley's son-in-law, he makes solving these incidents his personal mission. Suffering from a painful toothache and becoming increasingly socially detached, he behaves more and more unpredictably. He follows Jack, convinced that Jack is running away from something and is involved in a conspiracy. After a car chase, a nervous Jack finally pulls over, threatens Wade with a rifle, shoots out his tires, and drives off.
Finally, Wade is fired for harassing Jack and trashing Lariviere's office. He collects Jill from her mother's house, where his ex-wife furiously castigates him over his plans to sue for full custody. At a local restaurant, after being verbally abused, he attacks the bartender in front of his daughter. Then Wade takes Jill home to find Margie leaving him. Wade grabs Margie and begs her to stay, but Jill rushes up and tries to stop the fight. In response, Wade angrily pushes Jill, giving her a bloody nose, forcing both her and Margie to drive off.
Glen, Wade's father, congratulates him for finally acting as a "real man." The latent aggression between the men culminates in another fight in which Wade hits his father with the butt of a rifle, accidentally killing him. Wade burns the corpse in the barn, sits down at the kitchen table and starts drinking.
Rolfe's narration reveals that Wade eventually murdered Jack and left town (possibly to Canada, where Jack's truck was found three days later), never to return. Rolfe relates that the town later became part of a huge ski resort partly organized by Gordon Lariviere, but he had nothing to do with either Jack or Twombley. Rolfe concludes that someday a vagrant resembling Wade might be found frozen to death, and that will be the end of the story.
