When Ridley Scott's Alien first released in 1979, the franchise was a visceral horror film with a science fiction aesthetic. It was a gritty and relatively simple premise which was executed masterfully, earning instant critical acclaim. The franchise built upon this success by expanding its scope, ratcheting up the action spectacle and horror by militarising the core dynamic in James Cameron's Aliens. Prometheus broadened the scope even further, by daring to ask questions about the nature of creation. Alien: Covenant is looking to fuse the two halves of this franchise in more ways than one, by spattering the screen with gore while expanding on the complex mythology of its eponymous creature, and finally answering where they came from.
The events of Prometheus appeared to suggest that the xenomorph was at least in-part a creation of the mysterious Engineers. However, returning director Scott has debunked that theory, teasing fans prior to the release of the sixth film in the franchise.
In an interview with Collider (via IBT), Scott discussed the nature of Alien: Covenant, and why now is the right time to answer a question that has bothered fans since the original released over 30 years ago:
"It shouldn't have really ended, so we've come back with a very simple idea: Who made them? [Alien] was just about there it is; it exists. And this is what it is...
So we've reinvented the idea of Alien, I think, which is that Covenant gets us a step closer to who and why was this thing designed to make human beings. And if you think it's them [the Engineers], you're dead wrong."
Scott's frank comments tease a much larger plot than the original entailed, with the suggestion that this film will bring viewers a "step closer" to understanding the nature of the creatures, hinting that audiences will not receive all the answers this time around. The sequel to Covenant is already written, so it's likely that this core question will straddle the two movies. While that may frustrate fans who were hoping for some concrete answers, rumours have begun to circulate about the evolutionary chain linking humans, the Engineers, and the xenomorphs.
There's a suggestion (posted on Alien-Covenant.com) that some higher power has seeded humans, Engineers, and 3-4 other iterations of humanoids throughout many universes. These higher beings supposedly have God-like powers, including the power to elicit massive scale natural disasters in order to change and reset ecosystems. The horror of a xenomorph reaching earth has been teased throughout the franchise with the general consensus that such an eventuality would lead to an extinction event. If these higher beings exist, however, they could have created the xenomorph as a form of divine justice. At this point, though, fans will have to wait to find out.