Pei Mingshu, the legitimate daughter of the Marquis's manor who has been separated for sixteen years, returns to the manor acting foolish, only to discover that her three older brothers each bear a death calamity. To confirm whether her three older brothers are worthy of her help, she hides her identity. First, she uses a pair of muddy feet to test her brothers' true hearts, discovering that her three older brothers have always missed her over the years and now unconditionally love her as well, which deeply touches her. Afterwards, relying on her profound arts, medical skills, and identity as the Phoenix Master, she saves her brothers one by one, liquidating the fake younger sister and the conspiracy of the Xuanyin Gate, and finally reclaims her familial affection, identity, and the happiness that belongs to her.