Shen Jinghan, the top scholar of the imperial examinations, is framed by powerful ministers and demoted to head constable of Qingxi County. In reality, he has been secretly ordered by the emperor to investigate a major illicit salt case. After taking possession of the evidence left by a murdered veteran constable, he brings down the local salt tyrant and the deputy county magistrate, earning enough merit to return to the capital. Framed and imprisoned, he escapes twice and joins forces with his allies to dig deeper into the corruption, successively bringing down a host of corrupt officials and exposing the Marquis of Zhen Guo as the mastermind. When rebel forces threaten the border, he is entrusted with defending the city and suppressing the rebellion. After purging treacherous officials from the imperial court, he rises to the position of chief chancellor. Having achieved his ambitions, he ultimately retires from public life and returns to Qingxi to live in seclusion with his confidant.