Lin Tangtang, the legitimate daughter of General Beiwei, endures a tragic fate in her first life. While heavily pregnant and shivering in the snow at the Jingbei Hou Mansion, she discovers that her fiancé, Yang Chen, has returned from the northern border to marry her cousin, Lin Jiaojiao. Lin Jiaojiao reveals that she forged a treason letter using the handwriting taught by General Lin, causing the Emperor to order the suppression of the Beiwei Army rather than sending reinforcements. Yang Chen accepts the title of Grand Marshal for suppressing the rebellion, reducing Lin Tangtang to a concubine. Heartbroken and betrayed, Lin Tangtang collapses in the snow during premature labor and dies, watching her betrayers celebrate behind closed doors.
Lin Tangtang awakens to find she has been reborn eight months into the past, to the moment she first arrived in the capital with Lin Jiaojiao after escaping the northern battlefield. Remembering her previous life, she realizes that her blind trust in Yang Chen and her failure to seek help from Crown Prince Qin Mo'an led to the destruction of her family. Determined to change her fate, she refuses to let Lin Jiaojiao accompany her to the capital and instead seeks out the Crown Prince, who had previously rescued her from a valley. She presents him with urgent military intelligence regarding the Beiwei Army's critical situation and pledges her family's allegiance in exchange for his aid.
Qin Mo'an, known as the Yan-faced Crown Prince, is initially skeptical but agrees to help after Lin Tangtang offers the Lin Family Head Jade Pendant as a token of loyalty. He recognizes her potential and strategic value, viewing her as a key piece in his political chessboard against rival factions, particularly the Second Prince, who is allied with Yang Chen and the corrupt Minister of War, Wu Xiong. Lin Tangtang also confronts her past abuser, Wang Momo, when the servant attempts to forcibly bring her back to the Marquis Estate, publicly humiliating her and severing tendons to assert her dominance.
Upon entering the Jingbei Hou Mansion, Lin Tangtang faces hostility from Yang Chen's mother, Madam Yu, who assigns her to the dilapidated West Garden and sends three mamas to enforce strict etiquette and monitor her movements. Lin Tangtang quickly turns the tables by blackmailing the mamas with their secrets, forcing them to report to her instead of Madam Yu. She also outmaneuvers Lin Jiaojiao, who attempts to sabotage Lin Tangtang's arm to prevent her from winning the Crown Prince's favor, only to find that Lin Tangtang had anticipated the move and protected her wounds with waterproof armor.
Lin Tangtang executes a plan to sow discord between Yang Chen and his ally, General Luo Chi, by planting a jade pendant at the residence of Luo Chi's mistress. This causes Luo Chi to accuse Yang Chen of betrayal, creating a rift between the two men. When summoned before Madam Yu and the estate's elders, Lin Tangtang refuses to kneel, citing that she is not yet married, and counters their demands for subservience by pointing out the hypocrisy of enforcing rules on her while sparing their own daughters. The story concludes with Lin Tangtang firmly establishing her authority within the Marquis Estate while secretly coordinating with the Crown Prince to expose the treason against her father and reclaim justice for the eighty thousand soldiers of the Beiwei Army.
