Infernal Affairs III picks up where the first film left off. Ming (
Andy Lau) is cleared of any charges involving Yan's (Tony Leung) death, and is eventually assigned to the Internal Affairs division. He discovers that another cop, Yeung (Leon Lai of
Fallen Angels), quickly rising through the ranks of the police department, has a mysterious link to Shen (Chen Daoming of
Hero), who was apparently Sam's (Eric Tsang) connection to the mainland. Ming strongly suspects that Yeung is another one of Sam's moles, and is determined to expose him, while keeping his own connection to Sam a secret. It's a tricky proposition because Yeung also seems to suspect Ming, and appears to have the same goal in mind. With the help of Dr. Lee (Kelly Chen), Yan's psychiatrist, Ming looks deeper into Yan's final days, and flashbacks explore the undercover cop's dealings with both Yeung and Shen. Eventually, Ming finds an incriminating tape of Sam conversing with his mole, and has a climactic confrontation with Yeung.
Anthony Wong and Chapman To also reprise their roles from the first two films in flashbacks. Infernal Affairs III was shown, along with the rest of the trilogy, at the 2004 New York Film Festival, presented by the Film Society of Lincoln Center. ~ Josh Ralske, All Movie Guide