Director Ridley Scott’s moody Alien is one of the greatest sci-fi and horror films. And since he didn’t stick with the franchise, having handed off the heart-pounding Aliens sequel to James Cameron, it is with much anticipation that he returns to direct a prequel. Scott unveiled the official trailer Saturday at the WonderCon 2012 in Anaheim, Calif. Michael Fassbender plays an androidlike character, and Charlize Theron also stars. Scott and the cast have been secretive about the plot, noting nothing beyond the basics: a group of explorers find mysterious hieroglyphs that send them off to discover the origins of mankind. Prometheus is not only the name of the spaceship they use but also, of course, the brainy Titan who helped Zeus come to power but later stole fire for mankind—his name means “forethought” in Greek.