Lin Wanyue, the legitimate daughter of the Duke of Zhenguo, married Prince Li Huanyu because of her family's power, but was ignored by him. She was framed by her sweetheart Su Yao and sent to the cold palace. She learned tactics and gathered evidence in a desperate situation, and finally waited for the prince to repent. When Su Yao colludes with traitors to rebel, the two work together to put down the turmoil. Li Huanyu deposes Su Yao and helps Wanyue regain the position of crown princess. They reunite and face the future together.
