Kong Hongjun has lived his whole life in the mystical Taihang Mountains, a haven for yao, spirits with powerful magical abilities. A half-yao himself, he knows little of the human world until the day the ruler of the mountain instructs him to conceal his identity and descend to the mortal realm. There, he is to join the Great Tang Exorcism Department in the ancient capital of Chang’an.

Upon arrival, Hongjun finds himself under the command of Li Jinglong, a down-on-his-luck general with no magic of his own. Along with his fellow exorcists, a group of enigmatic young men with uncanny abilities, Hongjun and Li Jinglong must work together to protect Chang’an from the evil yao that lurk in its darkest corners. But greater machinations are afoot in the capital - and in order to confront them, Hongjun will have to reveal all of himself to Li Jinglong.