Two young men, one is a new recruit in the Hong Kong Triads, the other a new recruit into the police Academy. Each takes the opposite route: the new Triad recruit enters the police academy in order to become a mole; the police cadet is “expelled” from the academy and goes undercover into the Triads. Both men have been undercover for ten years and both excel at their perceived careers.

Lau plays Inspector Lau, the undercover Triad member, who is a highly respected member of the HK police force. When it is discovered that there is a mole in the force, Lau is the one enlisted to root him out.

Leung Chiu-Wai is Yan, the undercover cop, who is sick and tired of being a mole. Only one person on the force, SP Wong, Yan's boss and friend (a stoic Wong), knows his true identity. Wong promises Yan this latest assignment will be his last – a promise which Yan has heard before.

Yan's assignment deals with Sam (Tsang), a Triad boss and Lau's boss as well. As the cops try to capture Sam, Lau tires to stay one step ahead of the cops by informing Sam of their movements. At the same time, Yan tries to alert the Wong to Sam's movements.

It is during this operation that both sides discover there is a mole among them. Both must discover and expose the other mole before they themselves are found out.

Infernal Affairs is a savvy, taunt police thriller and honestly one of the best movies I've seen in a long time. It's no wonder Brad Pitt wants to produce an American version (which we won't hopefully fuck up). Both Lau and Leung do a brilliant job portraying an over-confident, smooth gangster and a frazzled, sad cop respectively. Wong is solid as the unflappable police chief. The only misstep in casting is Tsang as Sam. Too soft and angelic looking to be believable as a harden Triad boss, Tsang is out of place in a drama of this caliber. Kelly Chen has a small, silly part as a Yan's shrink but thankfully that subplot is not given a whole lot of screen time.

Sammi Cheng and Elva Hsiao portray women from the past and present in the two moles lives. Without so many words, both women are melancholy reminders of what these men have lost due to career ambition and missteps. Two small and yet beautiful characters that help make this movie all the more intense.

The cinematography is beautiful, both slick and understated. One particular shot of an elevator gives the viewer a chill since we don't need to see what's going inside in order to know what is happening. And also brings the title into chilling perspective. Don't miss this movie!

Watson Scale: 6