The true legitimate daughter Cui Lingyi, raised in the countryside, returns through rebirth, carrying fragmented memories and supreme medical skills back to the turbulent Duke of Zhenguo's Mansion. Facing the fake legitimate daughter Cui Wu—who stole her identity for eighteen years and was also reborn—step-by-step traps, as well as the behind-the-scenes avenger Wei Huan stirring up the court's struggle for the crown prince position, the Prince of Jing's heir Yuwen Ji steps forward, using a marriage contract as a shield to protect her safety. Cui Lingyi brushes aside heavy mazes of hairpin-breaking frame-ups, musk deer plots, forged marriage certificates, and blood drops for paternity tests, while investigating the truth of the baby swap at the royal temple eighteen years ago, and fighting against forces that collude with the Third Prince to attempt treason and revenge using the Cui family's old grievances.