This is a drama about 2 men and 1 women who have fallen out of life due to tragic events become police corruption investigation teams and discover the realities of power.
Do Chi Kwang (Han Suk Kyu) is an elite detective. He is thoughtful and smart. He is also proud of his record of catching criminals. After going through a series of cases, he realizes the importance of work done by the police on corruption. He then becomes the chief of the internal affairs investigation team.
Kim Young Koon (Seo Kang Joon) is a police officer and member of the mobile patrol team. He acts cold to other people, but he is actually tender with a warm personality. He does not associate with other people. By accident, he happens to meet Do Chi Kwang. Do Chi Kwang got involve in a the tragic affair, which Kim Young Koon tries to forget. To find the truth behind that case, he joins the internal affairs investigation team.
Han Tae Joo (Kim Hyun Joo) is a popular lawyer. In her past, she worked as a prosecutor. She became entangled in a case unexpectedly and survived even though her life was in grave danger. She then quit her job as a prosecutor and became a lawyer. She meets Do Chi Kwang and Kim Young Koon and joins their internal affairs team.