Set 3 years after the very first season, members of the National Security Solution (NSS) group, consisting of Jung Yoo Gun, Ji Soo Yeon as well as other representatives attempt to draw the curtain on strange team IRIS. Representative Yoo Gun is the leader of the NSS TF-A team. While he takes on Baek San, Yoo Gun comes to be associated with a case which alters his destiny forever.