Leningrad pioneer Kolya Tsvetkov demonstrates a mobile radio set he has built. Sasha Zyurin from Vyatka launches a homemade plane. Pioneers demonstrate: a device for cleaning knives, a mechanical helmsman. Pioneers study insects and birds. The guys are having lunch in the dining room, blowing horns, studying the globe. Pioneers of Novosibirsk study military affairs, play war games.