Yang Ling, a modern migrant worker, unexpectedly enters the fantasy-filled Dafeng Dynasty, and changes his face to become a watchdog named Tongluo - Xu Qian, who oversees hundreds of officials and solves crimes for the people of Dafeng.Relying on what he has learned in modern times and using scientific knowledge and reasoning expertise, he successfully solved a series of bizarre cases and was known as the master of solving cases in Dafeng.And in this world of Dafeng, where there are demons, magic, treacherous people's hearts, and surging undercurrents, he and his like-minded partners chose to face the difficulties and dared to sacrifice themselves to jointly fight against the dark forces of the court and speak out for the people and justice., work together to protect the stability of Dafeng.