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.
Solid Hong Kong action-thriller with good performances and fine direction. I do think The Departed did better with connecting the plot and character development (particularly between the undercover cop and psychiatrist). Also thought The Departed was more suspenseful. But that said, Infernal Affairs is a fine film. **3.75/5**