Dr. Kim Myung Guk has been missing for three years. Ever since a terrorist organization tried to capture him for his development on nuclear weapons. But now, the National Anti-Terror Service (NTS) has information that the organization has found him.
With the President's daughter kidnapped, the NTS must join forces with Son-Hyuk and his men in order to get her back without giving the terrorist what he wants.
Son-Hyuk and the DIS are requested to move their offices into NTS. Hye-In plans to use Jung-Woo's desire for her to gather classified information for the DIS.
Dr. Kim Myung Guk has been kidnapped and the NTS have no leads on his whereabouts. Meanwhile, Jung-Woo and Jae-Hee are sent to Japan to protect Korean pop star, BoA, from a terrorist threat.
The NTS finds out that Dr. Kim Myung Guk and the stolen SNC are both in Japan. Now they have to locate their exact location. Joon Ho sees this as his chance to rediscover his combat agent skills.
The SNC has been recovered. But now, Athena wants it back. They force Jung-Woo to get it back for them while holding Hye-In hostage. With Ki-Soo's help, Jung-Woo recovers the SNC and kills the terrorists. But his career with the NTS could be in jeopardy.
Lee Jung-Woo is on temporary leave from NTS. He heads to Japan to solve a missing clue that Dr. Kim Myung Guk left behind before his death. Son-Hyeok orders Hye-In to follow Jung-Woo and kill him. But will Hye-In's feelings get in the way?
Son-Hyeok has been brought to NTS for interrogation. Jung-Woo, Jae-Hee, and Joon Ho are in charge of it. Some of the evidence they find leads Jung-Woo to believe that Hye-In may be a member of Athena.
Jung-Woo confronts Hye-In about being part of Athena but, out of love for her, he lets her go on the run. Meanwhile, there is evidence of a spy in the Blue House. NTS finds out the it's Han Jung Pil, Jae-Hee's father.
Jung-Woo believes that Hye-In was the sniper that killed Han Jung Pil and he holds himself responsible for how his death has effected Jae-Hee. Meanwhile Athena prepares for an attack on the President before his meeting with Saudi Arabia.
Hye-In has been taken to NTS for interrogation. With her help, more Athena agents have been captured. But Andy breaks into NTS on Son-Hyeok's orders and threatens to blow the place up unless Hye-In goes free.
Athena has just made a new threat. But the target is unknown. Hye-In joins the NTS in order to track down Athena and locate their next target. Meanwhile, Ki-Soo is sent to New Zealand to find Seon Hwa and warn her that North Korea is after her.
The NTS has narrowed the Athena target threats down to the nuclear power plant and the Blue House as well as the other government buildings. But they still need more proof. Meanwhile, do to Son-Hyeok's recent failures, Athena is beginning to believe that they can't trust him.
Jung-Woo is certain that the terrorist attack will be at the nuclear plant. But without hard evidence the government can't send backup. NTS puts it's main focus on finding Son-Hyeok.
