In an era where demons are in power, they are the masters of the disregarded cultivators and mortals. The elders of the cultivators deem it necessary to send someone back in time to determine the origin of the demon lord and to prevent his awakening. Li Susu accepts the mission, becoming the mortal Ye Xiwu, the third daughter of General Ye, who is married to Tantai Jin, the hostage prince and future demon lord. She is determined to destroy Tantai Jin, who will massacre many in the future. However, as a witness to Tantai Jin's past life and his rise to power, an unexpected story emerges, complicating her quest.