Mu Zihan, the legitimate daughter of the Mu family, depends on her elder brother Mu Yan, who was poisoned while saving the Emperor and has been gravely ill ever since, with little hope of recovery. Her half-sister, Mu Ruyue, has lost her chastity through an illicit affair. Just as the Crown Prince is severely injured and falls into a coma, the Emperor issues an imperial decree ordering a daughter of the Mu family to enter the palace and bring him good fortune through marriage. To avoid the crime of deceiving the Emperor, Mu Zheng and his second wife, Lu Yan, attempt to force Mu Zihan to take her half-sister's place as the bride. Seeing through their scheme, Mu Zihan pretends to agree in order to protect her brother. Little does she know that the cold-hearted and ruthless Crown Prince staged his own grave injury and coma.