As illegal firearms flood into a gun-free South Korea, a resolute cop and a mysterious partner join forces to stop the chaos from sweeping the nation.

As a chief of staff in the National Assembly, Jang Tae-jun influences power behind the scenes while pursuing his own ambitions to rise to the top.

An education officer who was dispatched died after a gunshot went off in the dead of night. At the same time, deserters flee to the DMZ in the access control zone, and the 3rd platoon is urgently deployed to the DMZ search operation. There, the crew sees an unidentified soldier, not a deserter or a search crew.