The story begins with the Japanese occupation of Hong Kong coming to an end in 1945 and the remaining Japanese dying or leaving the territory. The British colonial government have yet to fully resume its duties. Citizens themselves are flushing out the remaining traitors one by one. Soon, multiple societies of different legions were formed within the HK underground. Each one tries to control the city in a time of very weak and corrupt governance. Eventually the big clans merge, expand and betray one another. The two major rivals, one run by the Lok family head Lok Zung-hing (Chow Yun-fat), the other by Ng Yat-tin (Tai Chi-wai) would collide.