Su Tan, a modern document inspection expert, traveled through time and became a small government clerk in Chang'an County of the Tang Dynasty. With a piece of handwriting and ink marks on a piece of paper, he uncovered layers of secrets under the prosperous appearance of Chang'an in its heyday. When the invisible ink revealed the secret words "Mingdemen, Haishi, Riding Alone", she realized that she had not arrived by chance - the handwriting on the fragment of the letter was the clue she had identified in her previous life. Faced with undercurrents in the court, clan rebellion and infiltration from the Western Regions, she used physical evidence as a blade and logic as a shield to join forces with Xue Chongjian, the demoted young minister of Dali Temple, to solve the case. He is good at reading people's hearts, while she only believes in paper and ink; one relies on connections to navigate officialdom, and the other uses technology to penetrate lies. Four volumes of serial cases and a secret letter lead to the foreshadowing of the Anshi Rebellion nineteen years later. The truth is not in the confession, but in the back of the paper.
Purpose: In an era where power and lies are intertwined, the real evidence never relies on oral confessions, but is hidden in the fibers of paper and the aging of ink. Trusting physical evidence is the bottom line for a sober person; learning to trust others is the beginning of a wise person's journey to wholeness.