Mou gaan dou III: Jung gik mou gaan

Infernal Affairs III uses parallel storytelling, flashing between the past and the present. Undercover Hong Kong Police Force officer Chan Wing-Yan seeks to uncover the link between Hong Kong Triad boss Hon Sam and the mysterious Mainland Chinese gang leader Shen Cheng. Senior Inspector Lau Kin-Ming, Hon's ex-mole in the Hong Kong Police Force, has been demoted to administrative duty pending an investigation into the deaths of Chan and Inspector Big-B.