The film action takes place in 1977, in the industrial city of Dzerzhinsk. The main characters are Mishka and his friend Dimka. The guys are preparing to watch pioneer detachments, in parallel extracurricular adventures of friends - fishing, rescuing a homeless dog grow into a real detective story with the participation of the school's director, local bandits, the activist of the squad's Council and, of course, a classmate a beautiful lady of the heart. Events put the children before the choice that life will not only bring to them - friendship or duty, private or public.