Narcotics officer Shaolun (Tony Leung Ka Fai), in order to bring down the local drug kingpin King (Michael Wong), forces a female street thug with an equally sketchy past, Coco (Rosamund Kwan) to infiltrate King's organization and provide information. What no one expected was for both men to fall for Coco, and Coco for King.

Young swordsman Lung Fei encounters strange omens portending the death of his fiancee Ting Tzu-chu. His enquiries with the help of Chief Constable Tieh Hu reveal an astounding story.