Li Tingyuan returns to the capital after a three-year absence, driven by her father's serious illness and the collapse of her family's status. She arrives at the Zhenguo Duke's Mansion, the residence of the Cui family, seeking refuge. Her best friend, Cui Yueyao, warmly greets her, but Li Tingyuan is haunted by memories of a single, chaotic night three years prior. During the Hundred Flowers Banquet, she had accidentally shared a bed with Cui Zhuo, the cold and untouchable young master of the house. Cui Zhuo is the eldest son of the Cui family, a man of high status and icy demeanor who has never shown interest in women. Li Tingyuan fears that her presence will bring shame to his illustrious lineage, especially since she is now an orphan with no powerful family to back her.
Upon entering the mansion, Li Tingyuan is received by Cui Zhuo's mother, who expresses a desire to formally adopt her as a daughter to protect her. However, Cui Zhuo interrupts the proceedings and coldly rejects the idea of formal adoption. He argues that the Li family's scholarly status is not equivalent to the Cui family's centuries-old noble lineage, and such a union would invite scandal. Instead, he offers her a place in the mansion as an adopted daughter in name only, a decision that strips her of dignity but provides her with shelter. Li Tingyuan, desperate to secure a future for her younger brother who wishes to study under Great Scholar Xue, accepts the humiliation silently.
Life in the Cui mansion is fraught with tension. Li Tingyuan is assigned to manage the accounts of a rural estate, a task Cui Zhuo uses as a test, promising to grant her one condition if she completes it without error. During this time, she discovers that Cui Zhuo possesses a handkerchief embroidered with the character "Yuan," which she believes belonged to her from that fateful night three years ago. This revelation suggests that he may remember her, contradicting his outward indifference. Meanwhile, Cui Zhuo suffers from a mysterious illness caused by a Gu poison contracted during that same night, which can only be cured by finding the woman involved and completing the ritual. His mother has attempted to find another woman to cure him, but he refuses, waiting for the original woman to appear.
Li Tingyuan's past catches up with her when Guo Fan, a man who had previously harassed her, ambushes her at White Horse Temple. She manages to escape with the help of Xue Fangyu, a relative of Great Scholar Xue, but Cui Zhuo, who is also at the temple, initially appears indifferent. However, it is revealed that Cui Zhuo had secretly sent Xue Fangyu to assist her. Their interaction becomes increasingly charged as Cui Zhuo begins to show signs of recognizing her, though he maintains a cold exterior. He warns her about her appearance and behavior, hinting at a deeper awareness of their shared history. As Li Tingyuan works through the accounts, the political intrigue within the Cui family intensifies, involving corruption in the canal transport system and internal power struggles. Cui Zhuo handles these matters with ruthless efficiency, further establishing his authority while keeping Li Tingyuan at a careful distance. The story unfolds as a complex interplay of past secrets, social hierarchy, and the slow, painful reconnection between two people bound by a night neither can forget.
