In the 13th year of Tang Dazhong, many organizations against corrupt officials emerged among the people. Among them, the Feidao Sect, which was under the banner of "killing the rich and helping the poor to overthrow the court", was the most powerful. The headquarters of the Feidao Sect was located in Fengtian County, close to the capital Chang'an. In order to ensure the safety of Chang'an, the court ordered the Fengtian County Government to wipe out all the members of the Feidao Sect. The two chief constables of Fengtian County, Liu (Andy Lau) and Jin (Takeshi Kaneshiro), received an order to arrest the new leader of the Feidao Sect within a time limit. Suspecting that the dancing girl Xiaomei (Zhang Ziyi) of Mudanfang was the daughter of the previous leader of the Feidao Sect, Liu designed to arrest her and put her in the sky prison. Later, he and Jin set a trap again and let Jin turn into a righteous man to rescue her. He wanted to deceive her trust and find out the nest of the Feidao Sect, but what he didn't know was that in addition to dealing with Jin and Xiaomei in official business, he would also have some entanglements with them in private.