Cui Jingxian, the legitimate daughter of the Cui family, had been sickly since childhood and married into the English Duke's Mansion. To leverage the Cui family's influence, her husband Song Jinghui promised never to take concubines, yet secretly kept a mistress. On the night of her childbirth, she glimpsed her husband's scheme and resolved to protect her son. Skillfully drawing others into the plot, conflicts arose within the inner courtyard. Maneuvering calmly, she broke through heavy storms, relied on the situation to secure the foundation for mother and son, and ultimately helped her son inherit the peerage, carving out a safe and peaceful remainder of life for herself and her child deep within the marquisate's curtains.