Plot synopsis from Wikipedia

The title of the film is an allusion to Prometheus, a Titan of Greek mythology who stole fire from Zeus and gave it to humankind — an act which brought eternal punishment upon him. While actually the name of the humans’ spaceship in the story, the name “Prometheus” is used in a greater metaphorical sense. The film will focus on the mythology within the Alien universe. Set in the late-21st century, Prometheus will explore the advanced civilization of an extraterrestrial race responsible for the origins of modern humans on Earth,as well as the origins of the alien creature which made its first appearance in the 1979 film.