When North Korean secret agent Ji-won (Kang Dong-won) crosses the 38th Parallel on a mission, the National Intelligence Service (NIS) led by Han-gyu (Song Kang-ho) intervenes, and a shooting rampage ensues in the heart of Seoul. For the incident, Han-gyu is fired and Ji-won is deserted by his agency. Six years later, the two meet by chance and start a business partnership in order to steal information from the other.