The story narrates a magnificent legend where "demons capture demons." During the Zhenyuan era, due to the accidental death of the Bai Ze goddess, who governed the realms of humans and demons, the Bai Ze Order goes missing, leading to rampant demon beasts causing chaos and numerous bloody murders in the human world. At this time, the leader of all demons, "Zhu Yan," disguised as Zhao Yuanzhou, volunteers to "surrender" and proposes to help the imperial court form a demon-hunting bureau to quell the chaos. Wen Xiao, wary and suspicious of Zhao Yuanzhou, joins the demon-hunting bureau along with her childhood friend and consul of the bureau, Zhuo Yichen, who is adept in both detective work and swordsmanship; the cool and detached archer Pei Sijing, formerly of the martial camp; and the young, talented, but timid doctor Bai Jiu. Together, they form a demon-hunting team, confronting the demon beasts recorded in "The Classic of Mountains and Seas." As they solve cases, they gradually uncover the brutal truth behind the malicious acts of the demon beasts. Faced with a great responsibility and the loss of loved ones to dust, can the indestructible friendship of the demon-hunting team and the love between the top demon beast and the goddess break through this dilemma?