Han Jung Hyun is an agent of National Intelligence Service formerly Agency for National Security Planning, who has been hiding his identity for quite sometime. Choi Yeon Soo, a human rights lawyer, becomes the first head of the agency for justice. These main leading characters of the series uncover the truth, pitted against a huge force holding top position. The series tests their relationship as husband and wife when the secret life of Jung Hyun comes to fore.
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.