A 17-year-old case, known as the scam of the century, reemerges as a serial murder case in the present year 2023. It's a nationwide crime case thriller revolving around three people.
“Undercover” depicts the story of Han Jung Hyun, who has been hiding his identity for a long time, and Choi Yeon Soo, a human rights lawyer who becomes the first head of the Senior Civil Servant Corruption Investigations Unit to fight for justice.