Chen (Bruce Lee), a country boy decides to live with relatives in the city. Fearing for her sons life Chens mother asks him to take a vow of non-violence before he leaves home. He agrees to take the request and leaves the countryside to live with his Family. His oath is abruptly challenged when he learns that his cousins are linked to a local crime scheme and have gone missing. Chen becomes pressured to destroy the Big Boss and the villains involved with his Familys disappearance, and must take Action. Lee is faced with a choice, break a pledge to his mother, or let his Family die.