Shen Wan transmigrates into the body of the fifth Crown Princess. Facing Crown Prince Xiao Jingheng, who has already exposed and dealt with four transmigrated women in succession, she disguises herself as a traditional, reserved young lady and conceals her modern knowledge to stay alive. When the Crown Prince tests her with a modern song, she pretends to be clueless and gets through the ordeal. Later, unable to bear the suffering of the common people, she secretly proposes plans to manufacture cement and save the emperor, gradually revealing her abilities. Eventually, she discovers that the Crown Prince is actually a reborn individual. Together, they avert a crisis that threatens to reset the world, come to trust and love each other sincerely, and protect their empire side by side.