The heroine, Su Qingyan, was originally the legitimate daughter of a famous family. Because her father was unjustly imprisoned and all the family members were convicted, she remained anonymous and relied on her family's prison-breaking secrets and extraordinary talents to become the official of the first women's prison department in Dajing. She partnered with the loyal dog guard Shen Yan, the clever widower A Zhi, and the sinister master Jiang Xu to solve a series of unsolved cases, clearing the family's grievances while protecting the peace of the whole country.
