Um Tiewu (played by Jung Woo-sung), a former agent of North Korea's General Reconnaissance Bureau, was recruited to assassinate high-ranking North Korean officials who were planning a coup in the Kaesong Industrial Park on the border between North and South Korea. Unexpectedly, he was attacked in Kaesong, forcing him to escape with the seriously injured and unconscious top North Korean leader. Going to South Korea, the situation suddenly changed, and the Korean Peninsula stood on the brink of nuclear war...