Infernal Affairs (2002)

AKA: Mou gaan dou, 无间道, 無間道
Country: Hong Kong
IMDB Rating: 8.1
Genres: Crime, Drama, Mystery
Release: 2002-12-12 (Hong kong), 2003-09-05 (China), 2016-03-17 (South Korea)
Director: Wai-Keung Lau , Alan Mak
Writers: Alan Mak , Felix Chong
Language: Cantonese | English | Thai
Stars: Andy Lau , Tony Chiu-Wai Leung , Anthony Chau-Sang Wong , Eric Tsang
Runtime: 101 min
Awards: 23 wins & 24 nominations.
Plot: 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.
IMDB:tt0338564