Kim Sun-woo (
Lee Byung-hun) is a high-ranking enforcer and loyal subordinate of crime boss Kang (
Kim Yeong-cheol). The two share concerns over business tensions with Baek Dae-sik (
Hwang Jung-min), a son from a rival family. Recently, Sun-woo had beaten up Baek's men for overstaying their welcome at their nightclub. Kang, preparing to leave on a business trip, assigns Sun-woo to shadow his young mistress Hee-soo (
Shin Min-a), whom he fears is having an "affair" with another man. As Sun-woo performs his duty — following Hee-soo, and escorting her to a music recital — he becomes quietly enthralled by the girl's beauty as glimpses into his lonely, empty personal life become prevalent. When he does come to discover Hee-soo and her lover at her home, he beats up the man and prepares to inform Kang. However, he changes his mind and spares the two on the condition that they no longer see each other again, earning him Hee-soo's enmity. Later, a man asks Sun-woo to apologize for beating up Baek's men, but he refuses. Agitated, he gets drunk in his apartment, and is kidnapped by Baek's henchmen. They prepare to kill him, but Kang saves him with a phone call. Kang, who has learned of his attempted cover-up of Hee-soo's affair, questions his motive, but he doesn't answer. Kang orders his men to torture Sun-woo, but gives him a chance to fix his mistake. Instead, Sun-woo escapes and vows revenge. Sun-woo delivers Hee-soo a farewell gift, then attempts to buy a handgun. The deal goes bad and he ends up killing the arms dealers. This incurs a vendetta with the brother of one of the dealers, who goes to the nightclub where he works. Sun-woo lures Baek to an ice rink and kills him, getting injured in the process. Undeterred, he arrives at the night club and kills his way in. Confronting Kang, Sun-woo vents over how badly he has been treated despite his years of loyalty. Receiving no justification, Sun-woo kills Kang. Baek's henchmen, who have been trailing Sun-woo, shoot at him and Kang's henchmen. Sun-woo emerges as the only survivor of the battle, just as the arms dealer's brother appears. Heavily wounded bleeding profusely, Sun-woo recalls watching Hee-soo's music recital. That was the only time he was seen smiling. The arms dealer's brother then executes him. (We also see Hee-soo at home, opening a gift-wrapped package, sent to her, containing a decorative lamp, she wanted to buy earlier in the film, but didn't, because it was too expensive for her.) The film ends with a continuation of an earlier scene, where Sun-woo looks out of a window at the city below him. After making sure he's alone, he begins to
shadowbox his reflection in the glass, looking very happy. ==Cast==