Sunwoo is no ordinary hotel manager. Quick-thinking and efficient, he’s also the right hand man of underworld boss Kang. But tough guy Kang has a weakness: his young girlfriend Heesoo. Suspecting she’s unfaithful, jealous Kang orders obedient Sunwoo to take care of the problem. But when Sunwoo finds Heesoo with another man, he is unable to kill them without knowing why. Kang is furious and swiftly sends his gang members after Sunwoo, plunging him into a living hell. With nerves of steel, Sunwoo battles the gang alone. With each kill, he takes one step closer to Kang.