When Gu Yun Zheng, an associate professor of neurosurgery, goes on a medical aid mission in the (fictional) North African nation of Lakaya, he meets former student Su Wei An, a "dropout" 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 her odd behavior and resistance to his advances are because she carries the gene for Huntington's disease - an incurable disease which leaves her hopeless. He decides to give up his promising career and devote his life to researching a cure for Huntington's, fighting alongside his beloved to carve light out of the darkness.