Paul Fraser and Helen Fraser arrive at an isolated lakeside cabin, where tragedy strikes when a figure with an axe brutally murders Paul. Helen discovers the body, the car keys are missing, and she flees into the woods. She stumbles upon Odis Pickett, who insists he will phone the sheriff. Inside the Pickett farmhouse, Odis introduces her to his pregnant wife, Emmy Pickett; daughter, Sarah Pickett; and developmentally disabled son, Bo Pickett. Exhausted, Helen considers leaving but accepts the Picketts' offer to spend the night to avoid endangering herself. In the nearby woods, a figure watches the Pickett farmhouse.
As night falls, Odis drinks moonshine while Bo skins and boils a possum. Bo quietly accuses Sarah of prostituting herself for money, and she places a hex on him. Emmy reveals to Helen that she married Odis because her father owed him money, and hints that Odis is abusive toward her. Helen shares that she had a husband before Paul, who presumably died in the Vietnam War. Later, Odis gropes Helen while she sleeps; her screams wake Emmy and Sarah. Sarah accuses Odis of molesting her since she was twelve, and says she would castrate him if he touches Helen again.
Emmy urges Bo to go to the neighbors’ house to call the sheriff. While walking through the woods, an assailant kills Bo by impaling him on a spike fence. Odis continues to drink heavily. Helen tries to quietly leave, only to find Bo’s corpse on the front porch. A distraught Odis plans to bury Bo in the backyard, while Sarah accuses Helen of being a witch who has brought them misfortune. An angry Odis attempts to rape Helen, but Emmy comes to her defense, though unsuccessfully, as Odis finally assaults Helen.
The next morning, Helen awakens and unsuccessfully attempts to leave. Odis sends Sarah to the neighbors’ house to call a preacher for Bo’s burial. Sarah hears someone following behind her on a path, and, hoping to spare herself, calls out that she will help the assailant locate Helen. The figure approaches Sarah, only to strangle her with barbed wire. When Sarah fails to return, Emmy sends Odis to find her. After he leaves, Emmy gives Helen directions to the lake, hoping to help her escape. Odis finds Sarah in the woods, clinging to life, and attempts to load his shotgun before a figure grabs him from behind and murders him. The figure then approaches the Pickett house, knocks, and enters. The killer is revealed to be Jim, Helen’s first husband, who explains to Helen that he was in a prisoner of war camp in Vietnam and mistakenly presumed dead.
Still claiming Helen as his wife, Jim attempts to stab her to death, only for the mortally wounded Sarah to enter the front door and shoot him dead with Odis’s shotgun. Emmy consoles a distraught Helen on the house’s front porch, telling her the two still have one another at least.
