By the standards of the typical Hong Kong police thriller, Infernal Affairs is unusually low-key and thoughtful. Beautifully shot, well acted, and tightly edited, the film is a flawed, but acceptably psychologically taut and genuinely suspenseful portrait of two violent men struggling with their own worth as they work to ingratiate themselves to those they are duty-bound to destroy. Fans of Hong Kong cinema will be happy to see a slick Andy Lau, a disheveled Tony Leung Chiu-Wai, an intrepid Anthony Wong, and a charmingly sinister Eric Tsang, all of whom are in top form. Some of the supporting players don't fare quite as well. The love interests of the two main characters are essentially window dressing, and one ex-girlfriend of Yan's (Leung) momentarily pops up at of nowhere for no discernible reason. The young actors who play Leung and Lau's characters in their early years don't look enough like them, causing a little confusion early on. In fact, the first ten minutes of the film are so elliptical that they resemble the opening of the second half of a TV mini-series, where we see scenes from the previous episode to remind us of how we got to the point where the film proper begins. From then on, things improve. There's a bit of melodrama (the music tends toward the sappy), but there's also plenty of suspense, and a few neat surprises. The film is a treat visually, and thanks in large part to the charisma of the two leads, we end up caring what happens to Yan and Ming (Lau). Infernal Affairs delivers a much needed shot in the arm for Hong Kong cinema.