Infernal Affairs (2002)

It's a suspenseful crime-thriller directed by Andrew Lau and Alan Mak that follows the story of a police officer who infiltrates a triad group and another cop who works undercover for the same mafia. Both the undercover officer and the gang mole devote 10 years of their lives to their fake identities, resulting in complicated identity disorders.

"Infernal Affairs" was heralded as a comeback for mainstream Hong Kong film, which had been suffering from a creative drought up to that point. The majority of the more fascinating films came from either the underground or the mainland. Not only was it a huge worldwide success, but Martin Scorsese reinvented it as "The Departed." Despite the fact that the majority of reviewers deemed "Infernal Affairs" to be the superior film, it was denied an Academy Award nomination, and as many of you are aware, "The Departed" went on to win best picture in 2007.

Detailed information:
Directed by: Andrew Lau
Starring: Andy Lau, Tony Leung, Anthony Wong, Eric Tsang
Release date: 12 December 2002
Running time: 101 minutes