During the birthday banquet of Empress Wu Zetian, a mystery of a "red-eyed monster" suddenly broke out, and Wu Zetian ordered Di Renjie to supervise the case. Di Renjie and his apprentice Chen Jiangqiao came to Fangzhou to investigate the case, and met Shen Qingqing, a bad guy who also came to investigate the case. Through the investigation of the case, the three gradually approached the truth behind the "red-eyed monster", which triggered a series of serial events. In the process of handling this series of events, Di Renjie was upright and put the people first, expressing a sense of responsibility and mission that "every man is responsible for the rise and fall of the country", and finally successfully solved the mystery.