Set 3 years after the first season, members of the National Security Service (NSS) team, including Jung Yoo Gun, Ji Soo Yeon and other agents attempt to pull the curtain on mysterious group IRIS. Agent Yoo Gun is the leader of the NSS TF-A team. While he goes up against Baek San, Yoo Gun becomes involved in a case which changes his fate forever.
| Actor | Role |
|---|---|
 Jang HyukJung Yoo-gun | Jung Yoo-gun |
 Lee Beom-sooYoo Joong-won | Yoo Joong-won |
 Im Soo-hyangKim Yeon-hwa | Kim Yeon-hwa |
 Lee Da-haeJi Soo-yeon | Ji Soo-yeon |
 Kim Yeong-cheolBaek San | Baek San |
| OOh Soo-yeonNot listed | Not listed |
 Oh Yeon-sooChoi Min | Choi Min |
 Kim So-yeonNot listed | Not listed |
 Cha Soon-hyeongIRIS Agent, Clerk | IRIS Agent, Clerk |