Myung-soo was sadistic and cruel man who killed many people with poisoned pen or gun and become rouge agent to North Korea along with his father who is higher ranked officer and know Pyo Joon-sang since their training days in North Korea. Myung-soo seems bullied Joon-sang as junior He seems lust on Jung-hee despite for begin Joon-sang's wife driven by Jung-hee's death angry Joon-sang put poison on Myung-soo's neck and caused him dead