地狱空荡荡，恶魔在人间。十五年前，一群身份各异的罪恶权贵将都马市染黑成一座“地狱岛”，高中生晓笛惨遭权贵凌辱致死；十五年后，这些背后操盘者接连惨死，死状惨烈。曾目睹十五年前命案的方天阳与警官方正楠深入调查，惊觉这桩匿名杀人案不只是单纯的复仇，更是一场迟到的控诉。桩桩命案，层层黑幕，那张权力、金钱、欲望织就的黑色秘网背后究竟藏着多少不为人知的罪孽？

　　Kyohei Aizawa, an assassin for a covert non-governmental espionage group in Japan called "SEEK", is grieving over the loss of his girlfriend from a tragic plane accident. The leader of "SEEK",Ryo Mikumo, contacts him for an emergency mission; save a fellow agent, recover a new highly explosive liquid called "RDX@", stop a ruthless Yakuza leader, Sojiro Kotsuki, and his gang before they take over Japan. Although the Ninjas were thought to have disappeared... the new breed of assassins live on helping to protect Japan and all that is right; the Ninjas are coming soon.

　　Korea’s most intimidating actor, Heo Sung-tae (Squid Game), stars as Detective Oh Nam-hyuk—a well-meaning but spectacularly inept cop clinging to his badge by a thread. When a botched sting operation lands him in over his head, he’s forced into an unlikely partnership with Tae-bong (Jo Bok-rae), a razor-sharp informant whose cover (and savings) are blown by Nam-hyuk’s bumbling. With a smuggling ring to bust, a fortune to recover, and zero trust between them, the mismatched duo must navigate double-crosses, blown covers, spectacularly stupid raids, and bruised egos.

　　警官哈金卧底潜入红虎帮，并成功赢得该帮派的信任。他不仅成功揭露了他们的罪行，还必须直面这些残暴的罪犯。然而，他遭遇背叛，陷入道德困境，在不为人知的情况下为维护正义而战，他的忠诚度也受到了考验。