The evil cultivator Ji Zuodao possesses the art of human-skin manipulation and the supernatural power of blood mosquitoes. He passes the entrance examination for Bureau 749, an organization responsible for handling supernatural incidents. Partnering with the mind-reading black dog Lord Dog and the zombie Qiqi, he works alongside Liu Ming and others to solve a series of cases involving kidnappers, a mysterious restaurant, and the Hehuan Gu cult, while fighting against the evil forces of the Ascension Sect. Later, he accidentally enters a domain sealed by inner demons, reconciles with his own inner demons, and uses the domain's rules to strengthen his powers. He helps his colleagues at the bureau quell an ancient source of supernatural disturbances. While accumulating cultivation resources through his investigations, he never abandons his principles and remains determined to protect Jinghai.