At the beginning of the 20th century, Zhang Qi Shan and his father were subject to experimentation by the traitor Zuo Qian Zhi. Ten years later, Zhang Qi Shan seeks his revenge. He arrives in Changsha for the first time and meets Er Yue Hong. The two join forces to go against Zuo Qian Zhi and the monster that threatens the city.
Before joining the imperial court a young Di Renjie was a minor judge in Bianzhou. When his mentor Yan Liben was welcoming Empress Wu back to the imperial court from the Ganye Temple, he encountered a strange ghostly incident called "Qingji". Master Yan was wrongly accused of being the murderer who intended to kill Empress and was jailed. To unravel the mystery, Dee comes to Chang'an alone, and with the help of his lover Gongsun Yu and his friend Yang Lu, a small-time gangster in Chang'an, he solves the "Qing Ji" murder case
The tomb of Yan Dong, the former head of the Six Horsemen Division in Chang'an, is hit by tomb robbers and the Xuanmao pearl, which was used to suppress the demon king, is stolen, leading to the rise of demons in Chang'an City and the unrest of the people. The Chief Steward, Eunuch Fish (Luo Jiaying), orders Ma San (Wu Mengda), Wang Zhuge (Jia Bing) and Lei Yan (Xu Dongdong) of the Six Horsemen Division to suppress the demons and hunt for the pearl, and to hatch a terrifying plot.