Hyeong-do (SO Ji-sub) is a professional killer working for a company specializing in contract murders. Fronted as an ordinary metal trading company, killing is nothing more than daily business dealings here. Hyeong-do is one of the firm's best killers and a loyal employee. One day, he is assigned on a job with a newbie, Hun (KIM Dong-jun), who is supposed to be killed afterwards. Before meeting his fate, Hun asks Hyeong-do to pass the money he saved up for his family. After much hesitation, Hyeong-do visits Hun s house and meets Hun's mother, Mi-yeon (LEE Mi-youn) who turns out to be a one-hit wonder singer Hyeong-do used to adore as a teenager. After meeting her, he starts dreaming about a normal life. In the meanwhile, the company discovers that Hyeong-do didn t kill Hun as ordered. Hyeong-do, who now hopes to start a new life with Mi-yeon, finds himself being hunted down by his colleagues.