Hot summer, physically and mentally exhausted young Interpol Murakami (Mifune Toshiro) finished shooting practice, boarded the crowded and smelly bus home, on the way suddenly found that the gun was stolen. He struggled to catch up, but finally lost his target. Murakami was dejected to find Chief Sato (Qiao Shimura) and asked to relieve him of his duties, while the kind-hearted chief instructed him to ask for help from the senior criminal police officer Shichuan (Riji Kawamura) of the pickpocket class. Reminded by Ishikawa, the village remembered a woman standing beside the bus, it was the female habitual offender A Yin (acted the role of an Huizi). Unable to bear Murakami's pestering and beating, A Yin revealed the information of the pistol dealer. After that, Murakami went deep into the darkest corners of the city, looking for clues about handguns. At the same time, someone committed a crime with his pistol, and the situation became increasingly urgent. The general appearance of Japanese cities after World War II is presented alternately through the sharp eyes of a Murakami dingo.