Ye Wan, a modern female doctor, learned medicine from her grandfather from a young age. After his passing, she took over the Ye Family Clinic and unexpectedly discovered that, after nightfall, it could connect to the Great Xia Dynasty. Using modern medical techniques, she treats the people of Great Xia, earns ancient coins, and opens up trade between the two worlds. Restricted by the limitations of space, Ye Wan needs official identification in Great Xia to move around freely. She quits her hospital job, fights back against her oppressive superior, and cares for her comatose older sister. Meanwhile, she saves the frail and frequently ill Seventh Prince, Shen Shiqing, attracting his attention and investigation. Thus begins a turbulent story that shakes both worlds.