看似平凡的五金制造公司其实是一所铜金属一样冰冷无情的杀人公司。池炯道(苏志燮 饰)虽然整日西服革履，却是该公司业绩卓人的职业杀手。他为公司供职十年，没有一次失手，早已磨练出冷血气质和杀人不眨眼的狠心。但遇到来公司“打工”的新人罗勋(金东俊 饰)时，他突然看到了自己当年的影子。在和罗勋一起执行任务时，炯道有了片刻的恍惚。通过和罗勋的家人交流，他越来越感到亲情的温暖，更在遇到心爱的女人刘美妍(李美妍 饰)时，他的职业敏感发生了变化。在执行一次任务时，因犹豫而导致任务失败，这也让炯道第一次萌生退意，但事情远没有他想象的那样简单。一天之内，他从公司最有前途的职员变为公司的敌人，遭到原同事们追杀的“目标”……Ji Hyeong-do is an assassin for a company that masquerades as a metal trading firm. One day, he takes on a job partnering with a young man (Ra Hun) whom he is to kill afterwards. Ra Hun asks a favor of Hyeong-do, which is to give money to his family. Hyeong-do visits Ra Hun's home where he meets Ra Hun's mother, Yu Mi-Yeon, a former singer whom Hyeong-do admired in the past. Guilt, an unknown feeling up to this point for Hyeong-do, begins to take him over. When Hyeong-do's company realizes that he hasn't taken out Ra Hun as planned, Hyeong-do quickly becomes targeted.