Through the stories of Lin Yan and other police officers from the Eighth Brigade, the film shows the audience the dangers and difficulties faced by police officers fighting at the grassroots level. In order to combat crime and protect people's lives and property, the police officers, with Lin Yan as the core, often encounter various difficulties in the process of handling cases, and even face the possibility of injury or even sacrifice every day, but no one has ever backed down. This is exactly the performance of the public security organs across the country in recent years, establishing the Party for the public, establishing the police for the public, and practicing selflessness, fearlessness and willingness to sacrifice.