In 2020, after the colonization of the moon, the spaceships Vega, Sirius and Capella are launched from Lunar Station 7. They are to explore Venus under the command of Professor Hartman, but an asteroid collides and explodes Capella. The leader ship Vega stays orbiting and sends the astronauts Kern and Sherman with the robot John to the surface of Venus, but they have problems with communication with Dr. Marsha Evans in Vega.

On the outskirts of town, the hard-nosed Vienna owns a saloon frequented by the undesirables of the region, including Dancin’ Kid and his gang. Another patron of Vienna’s establishment is Johnny Guitar, a former gunslinger and her lover. When a heist is pulled in town that results in a man’s death, Emma Small, Vienna’s rival, rallies the townsfolk to take revenge on Vienna’s saloon – even without proof of her wrongdoing.