Set in modern-day San Fernando Valley of Los Angeles, the film begins with rebellious teenager October "Tobe" , going for a walk with her younger brother, Lonnie . The next day, Tobe goes to the beach with friends and when they stop for gasoline they are assisted by Harlan , a young man, though much older than Tobe - who affects a folksy, cowboy style. Tobe invites much-older Harlan to the beach. He accepts, and while at the beach, they share a passionate kiss. Afterwards, Tobe goes to his house and engages in sexual activities with Harlan. He then decides to take her on a real date which involves him and Tobe taking Lonnie to get something to eat. Later on that night they go on their "real" date dancing then later meeting up with Tobe's friends for another party. That is when he takes drugs under the influence of Tobe. She returns home the next day; having returned home long after she was expected, her father becomes enraged and she retreats to her room. He attempts to talk with her, and when she refuses to open the door, he pounds on the door and leaves visible damage.
Tobe continues to see Harlan. Her father's rage increases, and he manages to shatter her bedroom window. The romantically involved couple ride a horse that supposedly belongs to one of Harlan's friends named Charlie. Upon returning, Charlie claims he has never met Harlan and that the horse was stolen. The couple are held in police custody until Wade comes to pick up Tobe. She tells Harlan that they should no longer see each other. Harlan, however, is persistent. He takes out Lonnie to shoot guns without Wade's permission and is confronted by Lonnie's father, who is armed, threatening Harlan to leave his children alone.
Harlan is evicted from his apartment after shooting at his reflection in a mirror, imagining a Wild West style "shoot-out" scene. It is made clear at this point that he is, by some degree, mentally unstable or delusional. After an awkward incident at a local synagogue, where he is abruptly ushered out, he breaks into, presumably, his father or foster father's house, who is revealed to be a Hasidic Jew. He leaves the letter he has been narrating throughout the movie after taking multiple Jewish memorabilia, and the contents of a box, in a closet, inscribed with his name. He breaks into Tobe's house and packs a bag so they can run away. When Tobe comes home to find him, she is dumbfounded, happy to see him at first, but slowly realizes he is deranged and tells him she doesn't want to leave her family and that he should go. At that point, Harlan shoots her in the stomach, whether intentionally or by misfiring it is not clear.
When Tobe's father returns home to find Tobe alone on her bed, barely alive, he suspects Harlan, who has failed an attempt at calling 911 and run away. Wade rushes his wounded daughter to the hospital, where she is attached to a breathing machine and remains in a coma. Harlan, who is covered in Tobe's blood, then shoots himself in the side to conceal Tobe's blood and also make it look like it was Wade who had shot Tobe and then shot at him. He finds Lonnie and talks him into going away. He convinces Lonnie that it was really Wade who shot Tobe, and that Harlan was wounded while trying to stop him. Tobe regains consciousness at the hospital and Wade realizes that Lonnie has been taken by Harlan. He pursues them. At night while Harlan and Lonnie are by a fire, Wade, Charlie and a detective named Sheridan arrive. Harlan shoots Charlie before riding off with Lonnie.
They stumble upon a Western motion picture set where filming has just begun. Wade and Sheridan arrive with two more cops. A shootout ensues in which Harlan guns down detective Sheridan and one of the cops. Harlan and Lonnie escape to a housing development under construction, where Wade finds them and another shootout ensues. Wade shoots Harlan to death to the horror of Lonnie.
Tobe and Lonnie are driven by Wade to a place where Tobe and Harlan had a pleasant day. Tobe is holding a box that contains her former lover's ashes. Her brother asks her what they should say about him. She replies, "Don't say anything, just think it," and scatters the ashes.
