A mysterious radio message is beamed around the world, and among the engineers who receive it are Los, the hero, and his colleague Spiridonov. Though the main focus of the story are the daily lives of a small group of people during the post-war Soviet Union, the film's enduring importance comes from its early sci-fi elements. It primarily tells of an engineer Mstislav Sergeyevich Los traveling to Mars in a rocket ship, where he leads a popular uprising against the ruling group of Elders, with the support of Queen Aelita who has fallen in love with him after watching him through a telescope.