The film tells about the holiday of Neptune in the pioneer camp "Youth". Moscow region, Istra district. Forest landscape. Cows at a watering hole. The gate of the pioneer camp "Youth". The pioneers are saluting. The territory and buildings of the camp buildings. Children swing on a swing. The pioneers of the 9th detachment of the camp are marching in formation. Feast of Neptune. Scenery depicting ships and steamers. Pioneers with the flag of the camp pass through the stadium. Solemn raising of the flag. The flag is waving. An impromptu children's performance. Conducting competitions between camp detachments. The line of pioneers is underway. Swimming pool. The opening ceremony of the traditional holiday of Neptune. Theatrical water show. Solemn exit of Neptune with his retinue, mermaids, water and devils. Mermaids are performing a dance. Sports. Pioneers tug-of-war, play ball, participate in competitions. The participants of the holiday swim in the pool.