"Undercover" is adapted from the BBC TV series of the same name. It tells the story of Han Jung-hyun (Ji Jin-hee), who has been hiding his identity, and Choi Yeon-soo (Kim Hyun-joo), a human rights lawyer who became the first director of the Air Transport Department for justice. Faced with a huge force that shakes the country in the name of interests, the two fought fiercely to protect love and justice. It is expected that by revealing the nature of power, the multifaceted nature of the people hidden in it and the right and wrong will be carefully investigated.