The spaceship Cosmocrator with a multiracial and multicultural crew of seven men and a woman undertakes an expedition to Venus in 1970. It had only just been discovered that a cosmic stone that had fallen in the Gobi desert sends signals. During their flight, the crew manages to decode the complete contents of the stone-like piece. It says that the inhabitants of Venus had planned an attack on Earth. Although it did not happen, the crew does not expect anything good when they land on Venus. They discover no living creatures, only technical systems that work on their own. A gigantic machinery of destruction that must have gotten out of control, has obviously turned against its builders and is still releasing huge amounts of nuclear radiation. The spaceship is in danger and the crew has to try to get back to Earth.

The first science-fiction film brought out in East Germany, The Silent Star is based on Stanislaw Lem's mysterious novel, The Astronauts (1951). The release is the original and unedited version of the film.