Song Shiyun, who studied medicine in the deep mountains, unexpectedly time-traveled into her background, originally the swapped legitimate daughter of the Song mansion. Abandoned in childhood and adopted by an old physician, she acquired exquisite medical skills and self-defense skills, and formed a nominal husband-and-wife relationship with the chaebol Gu Yunsheng through a piece of contract. After returning to Jinghai, she step by step investigated the truth of her background, exposed the baby-swapping conspiracy of Old Madam Song, Song Yaoting, and others, joined hands with her natal family, the Gu family, ferreted out the scarred murderer of that year, settled accounts with a crowd of villains, and moved from agreement to sincere devotion with Gu Yunsheng.