Undercover 2021 Yoon Ji woos father dies suddenly She wants to desperately take revenge on whoever is responsible for her fathers death Yoon Ji woo works for drug crime group Dongcheonpa Choi Moo jin is the boss of the drug gang With the help of Choi Moo jin and to uncover the reason for her fathers death, Yoon Ji woo joins the police department and becomes a mole for the drug group Yoon Ji woo is assigned to work in the drug investigation unit in the police department Her partner there is Detective Jeon Pil do