Modern criminal policeman Yan Tian accidentally traveled to a virtual dynasty called "Daqi" during a pursuit and became the lowest county official. Relying on modern criminal investigation technology and meticulous logic, he repeatedly solved strange cases, from the county government to the state capital, then to the Ministry of Justice, and finally entered the Jinyiwei system. In the turbulent court struggle, Yan Tian adhered to his original intention as a criminal investigator, used evidence to break the conspiracy, used wisdom to fight for power, and finally became the commander in charge of the Jinyi Guards, creating a criminal investigation system based on evidence and logic in this ancient dynasty.