A feared gangster named Jang Dong-soo finds himself the unexpected target of a brutal serial killer, narrowly escaping an attack that leaves him heavily scarred. Seeking retribution, he forges an unlikely alliance with a relentless detective named Jung Tae-seok, who has been on the trail of the elusive murderer. The gangster and the cop have starkly different methods and motivations, but they unite through a shared goal to bring the killer to justice before more lives are claimed. Both characters navigate the moral gray areas of their worlds, as their collaboration blurs the lines between legality and criminality.

The tension between Jang and Jung creates a volatile but effective partnership. As they close in on the killer, their investigation uncovers deeper layers of corruption and deception within both the police force and the criminal underworld. With limited time and high stakes, they must confront their own personal demons while staying focused on capturing the devil who threatens to plunge the city into further chaos. Twists and escalating dangers keep both the audience and the characters on edge, as they race against time to solve a case that could cost them everything.