In Southern California, handsome beatnik Duke and his young friend Boots terrorize a gas station attendant and then hitch a ride with salesman Ed Hogate. When Ed stops at a service station, the boys spot pretty Ann Carlyle. Duke, who guesses that Boots is homosexual, decides to seduce Ann in order to let the naïve Boots have his way with her. Holding Ed at knifepoint, Duke demands he follow Ann's car to her neighborhood, where the two young men break into the empty house next door. Upon discerning that Ann's husband Roger ignores her, Duke poses as a gardener in order to gain access to Ann's daily life. He soon befriends her and, after convincing her to invite Boots over, plies her with alcohol. The lonely, drunken Ann responds to Duke's sexual overtures, after which he carries her to the neighbor's bed for Boots to ravish. Boots, however, cannot go through with the act and races out of the house, where a furious Duke punches him. The two fall into the pool, fighting, and during the brawl Duke stabs Boots to death. Just then, Roger returns home and fights Duke. Roger has almost lost the fight when Ann appears with a gun drawn. She shoots Duke three times, killing him.