Infernal Affairs was the 2002 movie Martin Scorsese re-made as The Departed in 2006. The original Hong Kong film was co-directed by prolific filmmaker/cinematographer Andrew Lau and screenwriter Alan Mak. It smashed box office records and won dozens of awards in Hong Kong, before going on to successfully reach a global audience. The film was such a huge hit it spawned two follow ups, a prequel and a sequel.
Infernal Affairs is a taut, gripping thriller starring the cream of Hong Kong cinema. It follows the intertwining lives of Chan Wing Yan (played by Tony Leung, currently starring in Lust Caution) and Lau Kin Ming (played by Andy Lau, from House of Flying Daggers). Yan is an undercover cop who has infiltrated a triad gang. Ming is a hidden member of the triads who is rising quickly up the ranks of the police force. The parallel lives of these two rival characters, helplessly pitted against each other, ratchets up the suspense, and provides acute, emotive human drama.
The film opens with triad boss Sam (Eric Tsang) selecting young gang members to send into the police force, where they will act as his anonymous eyes and ears. In the training academy montage that follows, Yan's character is introduced. He is quickly identified as unsuitable for the force, and very publicly expelled in front of all the other cadets; but this is just a cover story. Superintendent Wong Chi Shing (Anthony Wong) has already picked him out as the ideal candidate for his undercover operation. From this point on, Yan is planted in the criminal underworld. Superintendent Shing is his contact, and the only person in the police force who knows Yan's true identity.
Infernal Affairs continues tracking the difficulties experienced by both Yan and Ming as they attempt to seamlessly blend in to their respective worlds. The pressure is piled on as the triad gang and the police department both realize they have moles, and attempt to flush them out. Conversely, although they work for opposite sides, Yan and Ming have a shared understanding of each other's gravely precarious situations. The underlying subtleties suggest that they are more similar than they are different, and indeed their situations are almost interchangeable.
In Scorsese's adaptation, the similarities are further highlighted by using actors who resemble each other, and having them both (somewhat unbelievably) get involved with the same woman. This doesn't happen in Infernal Affairs, but it is easy to see why Scorsese did it. Infernal Affairs includes a somewhat un-necessary sub-story about Yan's ex, which is totally extraneous to the main plot, and also an un-developed love story between Yan and a therapist. Scorsese simply took the therapist character and Ming's girlfriend Mary and made them into one person.
Infernal Affairs does have its problems. The film is very confusing to begin with, throwing an awful lot of information at the audience, which is hard to digest, especially via subtitles. It also doesn't help that the main characters are played by different actors in their youth. However, it is well worth persevering with Infernal Affairs. As the story progresses it gets much easier to follow, and draws the viewer into an intricately realized world. Anyone who has already seen The Departed will have a good idea what is going on anyway; Scorsese made a fine film from the bones of Infernal Affairs; but there are some major differences between the two films. Prior knowledge is not necessary to enjoy Infernal Affairs, but fans of The Departed are certain to find their viewing experience is enhanced by watching the original.
For further info on Tony Leung and Andy Lau try these useful English language websites.