Clay Hewitt drifts into a small Kansas town in 1955, seeking work to fund a visit to his older brother in California. He quickly forms a connection with Kitty, the local beauty queen, and befriends the quiet farmhand Earl, who helps him land a job at a cattle farm owned by the wealthy widow Delilah Ashford Potts. Delilah is known for maintaining sexual relationships with her young employees, and the town is still reading the scars of her husband’s suicide after catching her cheating on him.
Clay rejects Delilah's advances and soon finds himself at odds with her latest lover, Joel Carter.
Clay befriends Delilah's sensitive and introverted son, Joseph 'Flyboy' Potts, who has just returned from a psychiatric institution and whose only companion is his late father's aging pet bull. Flyboy was institutionalized for eight years after finding his father's corpse as a child, and he endures constant humiliation as Delilah makes him cook and clean for the farmhands, who frequently mistreat him. Clay takes Flyboy under his wing and shares that his older brother died in an accident two years prior. At Clay's suggestion, Flyboy asks Delilah to be allowed to work with the animals, but Delilah responds by having Joel Carter tie up Flyboy and force him to watch as she castrates Flyboy's pet bull, which bleeds to death. Horrified by Delilah's cruelty, Flyboy ends his romance with Delilah and leaves the farm, and Delilah departs soon afterwards for a business trip.
Clay confesses to Kitty that he is on the run from the authorities after being wrongfully blamed for the death of an old girlfriend in his hometown—they were having sex in a pool when she slipped and broke her neck. He plans to skip town and enlists Kitty's help to teach Flyboy how to stand up for himself before leaving. Kitty sets Flyboy up with one of her friends, but when she tries to get intimate, Flyboy breaks down and tells Clay that Delilah sexually abused him when he was a child and arranged for his father to catch them, driving him to suicide, for which Flyboy blames himself. Disgusted, Clay decides to take Flyboy with him.
While Flyboy and Kitty wait for him at the lake, Clay returns to the farm to retrieve his payment and is confronted by Delilah, who has learned about the criminal charges against him. Delilah reveals that she became pregnant from being raped by her father, whom she killed in a fit of rage. Her husband, an old friend of her father, agreed to marry her and raise Flyboy as his own son to spare her shame, but Delilah could never bring herself to love either of them, and instead sought to destroy them. She blackmails Clay into having sex with her in exchange for not turning him in. Flyboy returns to the farm to search for Clay and finds him in bed with Delilah, as she had intended. Heartbroken, Flyboy commits suicide in the same manner as his father did. An enraged Clay goes after Delilah, but she shoots herself before he can reach her. Kitty arrives and comforts Clay as he mourns Flyboy's death, and they leave town together.
