On the eve of being forced to celebrate the wedding for her sister-in-law, Shen Yunning, a concubine, accidentally discovered a scroll of green bamboo slips handed down from her ancestors. This bamboo slip can reveal the "real past" related to dynastic laws, case files, and official documents, but the picture only appears for a quarter of an hour before disappearing. She used this bamboo slip to expose the lie that Prince Wu'an was "terminally ill" in public on the way to the wedding - he had simply been given a chronic poison. This move not only prevented her from becoming a widow on her wedding night, but instead became the "savior" of the Marquis of Wu'an Mansion. She then used the excuse of "finding out the truth about the prince's poisoning" to use the power of the bamboo slips to investigate more old cases step by step. Eventually, she discovered that the death of her biological mother was closely related to the corruption case of the minister of household affairs, and a chess game in which a concubine stirred up the shady story of the entire officialdom began.
