Finally & thankfully Jon Spaihts original Alien prequel screenplay has been released. The writer's direct prequel to Ridley Scott's Alien before Lost's Damon Lindelof came in & created a more autonomous work devoid of well-known franchise icons as xenomorphs & face-huggers. Prometheus simply frustrated, it delivered really beautiful imagery but ultimately fell flat on its face in what it attempted to project & explore. Saying that the deleted scenes contained within the DVD & Blu-ray releases do offer up a lot of answers & are worth checking out. So if your curious to what might have been pre 'Lost dude' check out Spaihts script Alien: Engineers here. The writer himself has verified its authenticity as you can see from the Tweet.