Popular science film about the preparation of the October Revolution of 1917, about the period of emigration of V.I. Lenin in 1907-1917. Photos of V. I. Lenin, N. K. Krupskaya, I. G. Tsereteli, D. S. Merezhkovsky, P. B. Struve, A. A. Bogdanov, A. V. Lunacharsky. V. I. Lenin's letters to A. Lunacharsky, A. I. Elizarova-Ulyanova. Books and articles by V.I. Lenin. Articles from magazines and newspapers of the early 20th century. Views of the cities of Geneva (Switzerland), London (Great Britain), Library of the British Museum in Paris (France). The film is illustrated with landscapes of the sea, volcanic eruptions, rain, thunderstorms, lightning, storms.