July 18, 1991
Star Chow is about to be kicked out of the Royal Hong Kong Police's elite Special Duties Unit. But a senior officer decides to give him one last chance: Star must go undercover as a student at the Edinburgh High School in Hong Kong to recover the senior officer's missing revolver.
November 2, 2000
Hong Kong detective Chan [Anthony Wong] travels to the mainland city of Quangxi in search of the killer of his partner years earlier. Along with his new partner Lily Yeung [Li Fei], a mainlander living and working in Hong Kong, they enlist help from Wendy Wu [Carrie Ng], chief of an elite all-female SDU.