Some 30 years before the events of "Alien", scientists Elizabeth Shaw and Charlie Holloway discover a star map among the remnants of several ancient Earth cultures. Accompanied by David 8 and hoping to discover the origins of humanity, they journey aboard the spaceship USCSS "Prometheus" and arrive on the distant planet LV-223 in the Zeta2 Reticuli system, the same region of space in which the planetoid LV-426 from "Alien" is found. There they discover the ancient remains of an advanced civilization, called the Engineers (the same race as the dead pilot from the derelict ship in "Alien"), who were developing biological weapons in the form of a pathogenic mutagen which could have driven the human race extinct. The horrors they encounter result in the loss of the crew except for David and Shaw.