Jeong Mi-nam

Kyung-chul is a dangerous psychopath who kills for pleasure. Soo-hyeon, a top-secret agent, decides to track down the murderer himself. He promises himself that he will do everything in his power to take vengeance against the killer, even if it means that he must become a monster himself.

In 1375, China was in chaos between Yuan Dynasty and Ming Dynasty. Coryo (an ancient kingdom of Korea then) sent a delegation of many diplomats, soldiers and a silent slave to make peace with the new Chinese government. However, this delegation got charged as spies and sent in exile to a remote desert.