Kim Hyun-jun and Jin Sa-woo were training under the South Korean army's 707th Special Mission Battalion until they were scouted by NSS. In Hungary, Hyeon-jun accomplishes his mission and while in escape mode becomes wounded. Shortly later, Hyeon-jun finds out that he was betrayed by fellow agent Sa-woo. Seung-Hee attempts to help Hyeon-Jun escape, but a car explosion separates the two and both are misled to believe that the other person are dead. Hyeon-Jun is then saved by an unknown voice and learns of the secret society 'IRIS'.