Having lived his entire life on Mount Taiheng, half-yao Kong Hongjun is at last presented with the chance to explore the human world. He is assigned three tasks: uncover his father's murderer, eliminate the Black Jiao and its yao tribes that have infiltrated Chang'an, and return the Heart Lamp to a descendent of the Chen family. However, on his first night in the city, the Heart Lamp is mistakenly absorbed by military general Li Jinglong. After receiving a mysterious invitation to join Chang'an's Court of Exorcism, Kong Hongjun is reunited with a disgraced Li Jinglong as his captain. Alongside a fellow yao, a noble from a foreign land, and a cowardly scholar, Kong Hongjun and Li Jinglong must work together to purge Chang'an of the yao lurking in its streets. In the meantime, Kong Hongjun also needs to hide his true identity from Li Jinglong who loathes yao—all while attempting to retrieve the Heart Lamp from his body.