The drama is a psychological suspense drama about the middle-aged investigator, an outsider inside the police, who was once a bad lawyer for the prosecutor, and witnessed the tragic events that happened 15 years ago when the father of a policeman killed the young detective who was his mother. The three people involved in the murder case, and the three men and women whose lives collapsed because of this incident, in the special environment of personal apologization, reveal the true face of the secret police organization and find the reason for their desperate survival. Kim Hyun Joo plays Han Tae Joo, a legendary secular lawyer. He was originally a prosecutor who was in a stable position, but he resigned because he was seriously injured by a robber in the family. He temporarily went abroad to recuperate. After returning to China, he set up a law firm to serve wealthy criminals. Deliberately defending criminals, causing troubles, causing related people to commit evil and kill each other. Xu Kangjun plays the suspicious policeman Kim Young-kun. Possessing the outstanding observation ability of insight into prisoners, full of courage, agility, and clever mind, and because of his \”suspiciousness\” that he believes in nothing, he met the supervisor and secular lawyer to form an illegal investigation team.