After his pregnant fiancée is brutally murdered by a remorseless serial killer, elite NIS agent Kim Soo-hyeon embarks on a mission of pure vengeance. Unlike typical thrillers, Soo-hyeon does not simply seek to kill his target; he aims to inflict maximum suffering. He repeatedly captures, tortures, and then releases the killer, beginning a demented game of "catch and release" that spirals into a total descent into darkness for both men.

Si Kim Soo-hyeon (Lee Byung-hun), isang elite secret agent, ay nababalot ng matinding galit at dalamhati nang paslangin ng isang brutal na serial killer na si Jang Kyung-chul (Choi Min-sik) ang kanyang nobyang buntis. Hindi kontento sa simpleng hustisya, magsisimula si Soo-hyeon ng sarili niyang uri ng paghihiganti—hindi para patayin ang pumatay, kundi para sirain siya ng paunti-unti, paulit-ulit, at hagupitin ang kanyang pagkatao hanggang sa ganap na pagkalugmok.