A modern girl unexpectedly transmigrates into a historical romance novel, becoming Ji Chang'an, whose fate is tragic. At a critical moment, she awakens the divine lord Hei Yuhe and forms a life-sharing pact with him. Facing her treacherous fiancé Wen Yesong and a host of villains with ulterior motives, Ji Chang'an refuses to endure mistreatment any longer. Joining forces with Hei Yuhe, she gradually exposes conspiracies, roots out spies within the residence, and dismantles opposing factions. As they fight evil side by side, their feelings for each other slowly grow. After weathering countless crises and schemes, they finally unmask the mastermind and bring him to justice, protecting their family and family estate while finding a fulfilling love that lasts a lifetime.