Lin Wei, a modern medical student, travels through Chang'an in the prosperous Tang Dynasty in a laboratory accident and becomes a terminally ill orphan girl A Wei in the "Huichun Hall" of Buzhengfang. Before the high fever subsided, he faced the huge debt of "compound interest" and the desperate situation of bullies kicking in his door. He only held in his hand a mysterious silver hairpin engraved with the word "Yong'an" - this was not only a relic of the former imperial physician Su Mingyuan, but also the key to solving a ten-year-old case.
