In the early 1990s, "Public Order Defence Squads" in China — usually made up of discharged military personnel, unemployed young adults and local hooligans — were supposed to maintain public order in villages and towns. Most of the time, however, they ended up dealing with all sorts of mundane matters in their towns. The story begins with a mysterious case of serial dog killings. LI Lizhong, leader of the local defence squad, starts an investigation into the case, following a set of strange clues and studying them using piecemeal knowledge of primitive criminology and ichnology. After a string of hijinks, the squad catches the dog killer. However, the evidence also shows that the case is closely related to the accidental death of Lizhong’s father.