Hyun-soo, a C.E.O of a private detective agency, visits a pension with a client asking for her dog. While waiting outside of pension, he is falsely accused of kidnapping the client. During the arrest Hyun-soo, a serious car accident occurs and people misunderstand Hyun-soo as a prosecutor instead of a suspect. To find the real criminal, Hyun-soo pretends to be a prosecutor. Hwa-jin is an elite prosecutor but demoted to the provinces while trying to catch a law firm conglomerate Do-hoon, who colluded with the prosecutor’s leadership, meets Hyun-soo. Hwa-jin finds out the case is related to Do-hoon, she begins cooperating with Hyun-soo. While cooperating is on-going, they realize that there is a dirty truth behind the crime.