The modern girl Jin Qian accidentally returned to the Northern Song Dynasty, disguised herself as a man and joined Kaifeng Prefecture as a constable. Under the leadership of the iron-faced and selfless Bao Gong, she joined forces with the royal cat Zhan Zhao, the black-bellied lawyer Gongsun Ce, and colleagues Zhang Long, Zhao Hu, Wang Chao, Ma Han and others to solve mysterious cases such as "The Case of the Chopping of Beauty", "The Case of Chenzhou" and "The Substitute Prince". On the road of pleading for the people, punishing evil and upholding justice, she met the golden-haired mouse Bai Yuting, the mysterious courtesan Bing Ji, the phantom thief Yizhimei and others, and together they staged a series of detective stories that are both "silly" and nonsensical, and tortuous, bizarre and thrilling.