A celebrated Chinese hero returns to the mainland seven years after the fight that made him a myth, and assumes the identity of a masked crusader in order to expose the clandestine alliance between the Japanese and the mafia, and to procure a vital assassination list in this epic action thriller from INFERNAL AFFAIRS director Andy Lau. At the height of the Warlord Era, China is being torn apart though internal conflict, allowing Japanese forces to gain a foothold in Northern Shanghai. His mentor murdered by Japanese troops, Chinese avenger Chen Zhen (Donnie Yen) single-handedly defeats an entire dojo full of enemy combatants amidst a blinding shower of bullets. Though his body is never recovered, Chen Zhen is presumed to have perished in the fight. Flash forward seven years, when high-ranking Japanese officials rub elbows with ruthless gangsters in the lavish Casablanca nightclub as the impoverished masses starve in the streets. Suddenly, into the Shanghai social scene steps a wealthy entrepreneur named "Ku" (also Yen), whose obvious affluence quickly gains him an audience with the most powerful mob boss in town. Little do the local criminal masterminds realize it's all an elaborate ruse; by day Ku uses his relationship with the formidable gangster to gather intelligence on the collusion between the Chinese underworld and the Japanese military, and by night he dons a mask in order to fight the powers attempting to oppress his people. But the closer Ku grows to scorching beauty Kiki (Shu Qi), the more he risks blowing his cover. Later, when Ku discovers evidence of a top-secret Japanese hit list that threatens to shift the balance of power in their favor, he prepares to risk his life in a fight that could alter the future of an entire nation, and give the downtrodden masses hope for a better future.