Trama

The lives of Do Chi Gwang, Kim Young Koon and Han Tae Joo were destroyed by a tragic affair. They became members of an internal affairs investigation team for the police and they try to dig up the truth on who is behind the tragic affair.

Do Chi Kwang 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. Do Chi Kwang then becomes the chief of the internal affairs investigation team. Kim Young Goon 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 Goon tries to forget. To find the truth behind that case, he joins the internal affairs investigation team. Han Tae 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 Goon and joins their internal affairs team.—AsianWiki

A brutal murder committed 15 years ago turned three lives upside down. A decade and a half later, the trio - brought together by fate - goes on the hunt for answers. Kim Young Goon (Seo Kang Joon), a police officer who may be considered aloof and uncaring, joins an investigation unit headed by hardened long-time cop Do Chi Gwang (Han Suk Kyu). The nightmarish events 15 years ago still haunt Kim Young Koon - but his memories also provide no shortage of motivation. Do Chi Gwang, meanwhile, has led a quest to uncover widespread corruption as part of his unswerving pursuit of justice - a quest that has won him few friends in the police force. They are eventually joined by Han Tae Joo (Kim Hyun Joo), a former prosecutor who has become a lawyer. Will the trio unearth the truth about the fateful event that has shaped their destiny? And what dark secrets will they uncover along their way?