Adapted from the long documentary literature - Republic Criminal Police Choi Do-sik -, it takes the background of how the public security criminal police cracked many serious cases with bad social impact from 1990 to 2010 under difficult conditions. It tells the story of the public security criminal police's criminal investigation and criminal investigation techniques.Breakthroughs and innovations in other fields have shaped the images of many public security policemen across multiple police types, different police ranks, and different eras. They praise their youthful passion and continuous thinking about the meaning of the police profession in the process of severely cracking down on criminal crimes.Explore the aspirational feelings of pursuing justice and truth.