Mu Xi, a modern woman who died resentful after her father favored an illegitimate son over her, transmigrates into the body of the Jin Fang Heir in an ancient world. This original host was a biological princess disguised as a boy since childhood to secure her father's ducal title, living in constant fear of exposure. Raised in seclusion on Xihua Mountain, she was summoned back to the Jin Fang Residence only to be forced to take a so-called fake death pill, a scheme orchestrated by her stepmother Madam Gao and her father, Lord Mu Zhen, to eliminate her in favor of the favored second son, Mu Xun. However, the pill was actually lethal, killing the original host and allowing Mu Xi to take over.
Awakening inside her own coffin, Mu Xi discovers a maid named Ling Mei sneaking into the burial chamber to physically inspect the corpse, suspecting the cross-dressing secret. As Mu Xi confronts the maid, a violent male personality within her mind takes control of her body, brutally killing Ling Mei to silence her. This entity claims to be Mu Xi, but she realizes it is a dissociative alter or a separate soul inhabiting the same mind. The incident is interrupted by the arrival of Mu Xun, who knows the secret of the heir's gender, and Madam Gao, who brings her brother, Grand Marshal Gao Quan. Gao Quan aggressively tests Mu Xi, attempting to expose her by checking her pulse and physical strength, but is interrupted by the family physician, Divine Doctor Luo.
Confronting her father in his study, Mu Xi discovers a drafted memorial appointing Mu Xun as the new heir. She tears it up, openly defying her father and stepmother for the first time. She realizes that her previous life's trauma of being undervalued as a daughter has merged with this new reality, driving her to reclaim her legitimate status. She confronts Madam Gao's son, Mu Chong, and threatens his grandmother, Madam Han, with her sword to establish dominance and warn the household against further espionage. Understanding that she cannot remain confined, Mu Xi decides to leave the residence to build a public reputation. She plans to reveal her true female identity and claim her birthright as a princess, rather than remaining a shadowy male heir. As she exits the mansion, she vows to make the city aware that the Jin Fang Heir has returned from the dead, setting the stage for her struggle to reclaim her life and status against a family that sought to erase her.
