Gu Jingyu is reborn back to the moment just before her marriage, following a mix-up at birth. She uncovers the schemes of her relatives and her rival, Gu Yunshang, and takes the initiative to reclaim the betrothal to the Crown Prince of Chu that rightfully belongs to her. In her previous life, she met a tragic end after being betrayed. In this life, she moves with calculated precision: she warns Crown Prince Ying Chengyuan of a trap on the battlefield, exposes the conspiracy between her own father and a treacherous eunuch, and takes down the scoundrels and schemers to eliminate all her enemies. Ultimately, she joins forces with Ying Chengyuan to stabilize the court, helps him ascend to the throne, and is herself crowned Crown Princess, thus achieving a perfect revenge.