A film about the eruption of the Tolbachik volcanic massif in Kamchatka and the work of scientists from the Institute of Volcanology of the USSR Academy of Sciences. Geographical map of the USSR. Kamchatka. Smoking craters of the massif, streams of steam and water escaping from the crater, eruption of smoke, ash, fiery lava. Lava is sliding down the slope, trees are burning. Gopher on the mountainside. Walruses lying on a stone ledge in the sea, hearing the rumble of a volcano, jump into the water. Dead birds and animals among the stones, on the slopes. Camp of volcanologists. Volcanologists at work. Volcanologists sing the bird from their hands. A MI-4 helicopter flies over a mountain depression, flooded with water.