Chan Wing Yan, a young police officer, has been sent undercover as a mole in the local mafia. Lau Kin Ming, a young mafia member, infiltrates the police force. Years later, their older counterparts, Chen Wing Yan and Inspector Lau Kin Ming, respectively, race against time to expose the mole within their midst.
Andy Lau | Inspector Lau Kin Ming |
Tony Leung Chiu-wai | Chen Wing Yan (as Tony Leung) |
Anthony Wong Chau-Sang | SP Wong Chi Shing (as Anthony Wong) |
Eric Tsang | Hon Sam |
Kelly Chen | Dr. Lee Sum Yee |
Sammi Cheng | Mary |
Edison Chen | Young Lau Kin Ming |
Shawn Yue | Young Chan Wing Yan |
Chapman To | Tsui Wai-keung |
Dion Lam Dik-On | Del Piero |
Lam Ka-tung | Inspector B (as Lam Ka Tung) |
Wan Chi-Keung | SP Leung |