On the eve of her wedding, Yun Weiyue, the legitimate daughter of the Prime Minister's household, is publicly rejected by her fiancé and becomes the laughingstock of the city. Just as she falls into despair, an imperial decree arrives, appointing her as the official Crown Princess of Crown Prince Mo Jingchen. Everyone mocks her as a sickly woman who will not live long. But an assassination attempt on her wedding night tears away years of disguise. The seemingly frail woman possesses extraordinary martial arts skills and saves the Crown Prince's life in a moment of danger. Carrying the deep-seated vendetta of her mother's tragic death, Yun Weiyue forms an alliance with the wary Crown Prince. With careful schemes and brilliant strategy, she navigates the imperial harem and royal court, exposes her vicious half-sister, and crushes the treasonous plots of rival princes and powerful maternal relatives.