Han Jung-Hyun (Ji Jin-Hee) is an agent with the NIS (National Intelligence Service). He began working for the NIS while attending the police academy, when he was selected to work on a top-secret case where he met Choi Yeon-Soo (Kim Hyun-Joo). Using a false name, he fell in love with her, and they are now married with two children. Choi Yeon-Soo works as a civil rights attorney, seeking justice and truth. She is appointed head of the Public Officials Corruption Investigation Unit. Because of her appointment, her husband’s true identity becomes entangled in an uncontrollable situation.