The series tells the story of Yun Wei Shan, a spy longing for freedom, who infiltrates the palace to complete a mission. Within the eerie and mysterious palace, she encounters love and friendship, embarks on a journey of self-discovery.

Lu Wuyi, the youngest nine-tailed fox of the mysterious Formless Moon Sect, sets out on a mission with her friend Wu Wangyan to track down a fox demon on the run, Xiaowei. She infiltrates the Wei Mansion in Luo'an City, where she later crosses paths with Wu Shiguang, who holds a deep grudge, as well as Ji Ling and Li Jie, demon hunters from the Shilin Sect. In the process of uncovering the truth, they navigate between suspicion and cooperation, each driven by their own agendas. In their repeated struggles over the Dragon Deity's Power, their fates are changed time and again. To preserve peace in the world, they make painful sacrifices and ultimately subdue Jiu Ying, the lord of all demons, thus fulfilling an enduring quest of love and redemption.