Duel of Return [誓不兩立]

Drug lord Au Kai kills his man Li Tin-Kit after finding him as an undercover cop. Tin-Wah vows to avenge his elder brother, and he mixes himself in Au’s gang for collecting the proofs of his crime. The rival of Au, Sister Ha, takes advantage of the chance to make Tin-Wah kill Kan to weaken Au’s strength…