In 1970, debris from the 1908 Tunguska "meteor" are found which turn out to be recordings from a spaceship crashed there. The ship's origin is determined to be Venus, and an international team sets out with their spaceship "Kosmokrator" to visit the "Silent Planet", which is shrouded in clouds, and doesn't respond to contact attempts. While the "Kosmokrator" is in flight, the record is decoded and it turns out that the Venusians seemingly planned to invade Earth in 1908. Should the "Kosmokrator" still attempt to get in touch with the Aliens? And why are they silent now?