When Gu Yunzheng, an associate professor of neurosurgery, goes on a medical aid mission in Lacaya, he meets Su Wei'an, a "deserter" who has abandoned her medical career to become a businessperson. From bickering all the time to falling in love with each other, he gradually discovers that all her abnormal behavior is caused by a genetic disease called Huntington's disease. The love for his beloved one makes him empathize with the sadness and despair of this incurable disease faced by 30,000 patients and their families across the country. Finally, Gu Yunzheng decides to give up his promising career and devote his life to the research of curing this rare disease, fighting alongside his lover to carve light out of the darkness.

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