A terrible thing happened - Alyoshka’s classmate, a young hooligan, was kidnapped by “unidentified persons for an unknown purpose.” And yet, this event was not tragic. The school breathed a sigh of relief, and the grandmother of the abducted Rostik, having learned about the incident, said: “Serves them right!”, meaning the kidnappers. However, Dima and Alyosha had a different opinion and could not leave their friend in trouble. The search for Rostik turned into a real investigation, which, of course, was not without adventures and misunderstandings! But the insidious plans of the kidnappers were not destined to come true, because the brave and quick-witted “children of Sherlock Holmes” stood in their way of crime...