供职于国情局的青年警员金秀贤（李秉宪 饰）即将和心爱的女孩珠燕走入婚姻的殿堂，但是在一个飘雪之夜，独自驱车夜归的珠燕被人残忍杀害并分尸。秀贤痛不欲生，他找到四个主要嫌疑人的照片，开始独立追查凶手。经过一番调查，终于将目标锁定在为某学院包车的中年大叔张京哲（崔岷植 饰）的身上。张生活坎坷，性格极度扭曲，他经常袭击夜归的女子，并将她们无情杀害。秀贤找到张的据点，对其进行残酷的惩罚，却最终手下留情。侥幸活命的张反而由此激发所有的兽性，一场野兽对野兽的修罗之战渐次激烈…… 　　本片也部分镜头过于血腥而成为韩国首部被限制上映的商业影片。SPOILER: Jang Kyung-chul (Choi Min-sik) is a dangerous psychopath serial killer. He has committed infernal serial murders in diabolic ways that one cannot even imagine and his victims range from young women to even children. The police have chased him for a long time, but were unable to catch him. One day, Joo-yeon, daughter of a retired police chief becomes his prey and is found dead in a horrific state. Her fiancé Soo-hyun (Lee Byung-hun), a top secret agent, decides to track down the murderer himself. He promises himself that he will do everything in his power to take bloody vengeance against the killer, even if it means that he must become a monster himself to get this monstrous and inhumane killer.