In the 60s, Hong Kong had its darkest days in history. Under the British colonial rule, Hong Kong Police Force partnered with the triads and corruption was as rampant as ever. Ho (Donnie Yen), along with his fellow brothers Wil (Philip Keung) and Wayne (Wilfred Lau) slipped into Hong Kong illegally from Chaozhou. With his exceptional fighting skills and guts, Ho became a notorious fighter in the triads.
Supported by the British, Chief Detective Lee Rock (Andy Lau) created a set of triads regulation. Rock appreciated Ho’s ability, and helped him to escape from further torture by British Police. Ho was grateful to Rock for his help. During one of the gang fights, he even sacrificed his right leg to save Rock’s life, hence becoming “Crippled Ho”.
Indebted to Ho, Rock helped him to become the leader of the Big Four in triad society. Rock even sent his follower, Rose (Raquel Xu) to Thailand to cut off others’ source for drugs which made Ho the leader of the drug empire. Rock and Ho became extremely powerful and separately ruled the upper-world and the underworld of Hong Kong.
Until 1974, the establishment of the Independent Commission Against Corruption (ICAC) forced Rock to have a premature retirement. However, Ho did not want to leave and determined to become the sole dictator of the drug empire…