In this dark story of revenge, Bruce Lee"returns" as Billy Lo, whose companion Chin Ku dies of a sudden illness. But suspicion of foul play arises every time a gang attempts to steal Ku's coffin at the funeral. If Lo's younger brother hears about the episode, he renders his Buddhist master to inquire into the reality. His course leads him to the Castle of Death, '' the place Chin Ku was seen living. There, he meets and befriends an unlikely ally--a cruel and merciless martial arts expert who is also the master of the tower. But when the master dies under mysterious conditions, Lo ultimately ends up dueling with somebody.