After agent Kim Hyun-jun was killed by a sniper shot from IRIS agent Ray, IRIS went into remission to recover and reconnoiter. Three years have since passed and NSS is no longer a secret black-ops division as it once was, it is now a public entity to the world. Soo-Yeon, who has loved Yoo-Gun since they were young, begins to work as an NSS agent as well. Choi Min is newly appointed as the NSS deputy director. Her only purpose is take down IRIS.