Sometime in the near future, the Korean peninsula attempts to reunify. The South Korean government, which needs enormous funds for the unification to succeed, develops a landmark new technology called the TWR. The TWR is a high speed nuclear reactor and other countries want the technology.
To prevent terror in the aftermath of the TWR breakthrough, the government establishes a new organization named NTS (National Anti-Terror Service). Jung-woo (Jung Woo-sung) is transferred to the NTS group from the NIS. He's excited about the transfer and hopes to live the life of a real agent, but then discovers his main responsibility is to watch North Korean defectors.
One day, Jung-woo is given the order to travel to Italy to track terrorists from North Korea. Jung-woo goes to Italy with Ki-soo (Kim Min-jong). Ki-soo is a former North Korean agent who has defected to South Korea. Ki-soo's specialty is information on the European region. Up until now, Ki-soo was one of the North Korean defectors that Jung-woo had to monitor.
While in Italy, Soo-young (Lee Bo-young), the daughter of the South Korean President Jo Myeong-ho (Lee Jeong-kil), is kidnapped by terrorists. To solve the case the Korean government sends additional NTS agents including Jae-hee (Lee Ji-ah) to Italy. The NTS agents are able to negotiate with the terrorists, but during their negotiations Hye-in (Soo-ae) suddenly appears. Jung-woo and the other agents are surprised. Hye-in works as a guide at the exhibition hall in the NIS building. Jung-woo has always held strong feelings towards Hye-in, but he has never expressed his feelings towards her. Following Hye-in, Son-hyuk (Cha Seung-won), the chief of the East Asia branch of Department of Homeland Security in the U.S., suddenly appears as well. The NTS agents are mystified by their appearance.
Jung-woo learns that there is a secret "solutions" group within the NTS whose sole responsibility is to solve problems that others agencies can not. More surprisingly, Hy