Jiang Yueyao transmigrates into a tragic romance novel titled 'The Miracle Doctor's Legitimate Daughter: The Tyrant Prince's Palm Treasure,' assuming the identity of the cannon fodder younger sister of the female lead, Jiang Yuehua. The original story depicts the tyrannical Seventh Prince Chu Tianming abusing Jiang Yuehua as a substitute for his first love, ultimately ruining her family before realizing his true feelings and achieving a happy ending. Upon transmigrating, Jiang Yueyao faces immediate peril as the original character dies after running into a snowy wilderness. A System appears, assigning her the mission to save her sister and ensure world peace, promising a return to her original world and a cash reward upon completion. Armed with a System Shop, she survives by purchasing heat packs and food, inadvertently saving an unconscious Chu Wujin, who is revealed to be a prince in hiding. He gains the ability to hear her inner thoughts, establishing a unique connection between them.
Jiang Yueyao returns to the Jiang residence, where she is initially treated as an outsider by her parents, General Jiang Zhen and Lady Zhou Qiongying, who have just returned from border duty. Her cousin, Jiang Yuening, and grandmother, Old Mrs. Jiang, have exploited her vulnerability for years, stealing her inheritance and subjecting her to abuse. Jiang Yueyao confronts this oppression by publicly exposing the theft of goods sent by her parents, using evidence she had secretly preserved. With the support of her parents and sister, she forces the family to divide their estate, separating from the corrupt elder branch and securing her own safety and assets.
As she integrates into her new life, Jiang Yueyao discovers she can share her inner thoughts with Jiang Yuehua, who becomes her ally. Through these mental communications, Jiang Yueyao reveals future tragedies, including the false treason accusations against the Loyal Marquis Manor and the death of Young Marquis Xie Yanqing, a character who originally loved Jiang Yuehua. Determined to alter these fates, Jiang Yueyao actively works to protect her sister from the original male lead, Chu Tianming, and prevent the downfall of their allies. She also begins planning entrepreneurial ventures using knowledge from her previous life, aiming to generate independent wealth. The narrative follows her strategic efforts to navigate court politics, shield her family from impending doom, and redefine her role within the story's dangerous landscape.
