"Undercover", adapted from the BBC TV series of the same name, tells the story between Han Dingxian (Chi Jin Xi), who has been hiding his identity, and Choi Yun Soo (Kim Hyun Joo), a human rights lawyer who has become the first air transport director for justice. In the face of the huge power that shakes the country in the name of interests, the two men launched a fierce struggle to protect love and justice. It is expected that by uncovering the nature of power, the multifaceted nature, right and wrong of the people hidden in it will be carefully tracked down.