Her elder brother suddenly falls gravely ill. A clever and brave young girl, to share her family's burdens, disguises herself as a man and enters the county yamen to temporarily take the post of the master secretary. Faced with long-piled old cases and continuous appeals from the common people, she relies on careful observation, flexible reasoning, and sharp judgment to assist the newly appointed county magistrate in sorting out clues and examining evidence. From the mystery of the rice shop theft to the absurdly funny dispute over stolen chickens, she is not misled by appearances, nor does she favor anyone based on wealth or status. Step by step, she uncovers the truth, ensuring that those who have been wronged receive justice.