Song Kang-ho
The story follows Song Kang-ho as Agent Lee Han-gyoo of the National Intelligence Service (NIS) who falls from grace after failing to stop the assassination of a North Korean dissident. The sleeper cell responsible includes relative newcomer Ji-won played by Kang Dong-won, who gets marked as a traitor when the mission goes south. Six years later both men are working different jobs when they bump into each other and quickly form a bond.