The story revolves around four fledgling trainee police officers, Li Dawei (played by Zhang Ruoyun), Xia Jie (played by Bai Lu), Yang Shu (played by Xu Kaicheng), and Zhao Jiwei (played by Cao Lu). It tells the story of how they went through various cases at the Balihe Police Station in Pingling City, where police incidents are frequent, and how they quickly grew up under the guidance of the veteran police officers and eventually became qualified people's policemen.