Philip Russell, captive of the Committee, is bound to a device that sends shocks through his nervous system. The leader tells him he'll be released, and his outstanding debt forgiven if he'll just turn over his step-son, Jack (the Werewolf), to the business cabal. Philip refuses, and the torture continues.
Later, Jack announces to his sister, Lissa, and their friend Buck Cowan, that it's time he got his own apartment. Soon, he settles into his new place, where he meets the manager, Tina "Sandy" Sands. As she leaves, she accidentally bumps into the neighbor across the hall, Raymond Coker, who carries an armload of books about lycanthropy and the supernatural.
That evening, in downtown L.A., a junkie's attempted mugging of a young woman is stopped when a hooded man plunges a scythe into the mugger's back. He announces himself as the Hangman, and after the woman faints from the shock, he carries her off.
Jack, who's been busy fixing up his hew place, has lost track of the time, and rushes out to try to find a secluded stretch of beach where he can transform without endangering anyone. On his way out, he meets Clary Winter and Sam, two neighbors who take a liking to him.
Now his his wolf form on the beach, he is accosted by a group of partying bodybuilders. When the Werewolf fights back, one of them calls the police.
In the Hangman's dungeon-like basement, the mugging victim comes to, to see several young women chained and caged. The deluded vigilante explains he does this to keep them safe from the evils of society, then he relates his origins: inspired by his movie heroes, he enthusiastically fought in World War II, but was court-martialed for war crimes. After his release, he was unable, because of his record, to join any police force, and came to the conclusion that the authorities are corrupt. So he took matters into his own hands, and made himself the Hangman.
Later, patroling the streets, the Hangman witnesses a somewhat distressed couple, Buck and Lissa, who are having no luck finding her missing step-father. They are approached by the Werewolf, who has evaded the cops on the beach. He confronts the man-beast, whom Lissa recognizes. She tells the skeptical Buck that he's really Jack, and begs the Hangman not to harm him.
Ignoring her, the Hangman repeatedly swings his scythe at the Werewolf, landing glancing blows. Their conflict is briefly interrupted by the arrival of a police, and the two combatants run off. Before long, the Werewolf is caught around the neck by the Hangman's noose, and dangles from a streetlamp.