On a stormy night, Princess Shen Qingci and Wei Linyuan, heir to the Marquis of Zhen Guo, unexpectedly exchange souls. Shen Qingci enters Wei Linyuan's body, castrates herself, and enters the palace, becoming the Ninth-Thousand-Year Lord. For ten years, she endures humiliation while secretly investigating the wrongful case against the Wei family. Meanwhile, Wei Linyuan, trapped in the body of the princess, carefully maneuvers his way onto the imperial throne. Reborn, the two return carrying the estrangement and suspicion born from ten years of living each other's lives. They test one another and engage in a battle of wits. Beneath the turbulent court, conspiracies surrounding the old case run deep, and tangled feelings of love and hatred from the past continue to resurface. As they unravel court intrigues and resolve ten years of misunderstandings, they join forces to overturn the wrongful conviction that brought a bloody massacre upon the Wei family. In the end, they learn to look beyond power and remain true to their hearts.