What Is David's Real Plan?
As his Robinson Crusoe reference alludes to, David's base plan in Alien: Covenant is rather simple: get off the planet. He's essentially drained the world dry, using up all potential subjects and finishing his development of the alien, leaving him with nothing to do but survey his empty kingdom. To do this, he takes advantage of his knowledge of human nature, setting up a distinctly Earth-originated distress call that will immediately draw in any ship that gets within range. While in the film it's only picked up when the Covenant is hit by a power surge and Tennessee goes out beyond the ship to fix it, it would have been stronger to nearer passers-bys (the colony ship is a good few weeks out) and it's further worth noting David has no pressing time limit - a synthetic lifeform, he can wait for hundreds of years if need be.
What's of real importance here though isn't David's desire to get off the planet, but what his goals are once he leaves. His contempt for the Engineers is evident from his massacre, but he has over time developed similar feelings about their creation/his creators - humanity. This is where the main side of the story feeds in. Breaking new ground is the initial reading of Covenant the ship - all the crew are couples and they're starting anew explicitly like their American forefathers - but from David's sly contempt when learning of their mission, it's clear he sees them as simply clinging on to life even as they destroy the world around them.
David is in a position of pure superiority - he is is stronger, more resilient and of a higher intellectual power, yet still possesses the same self-thinking emotions - and, just as Peter Weyland once proclaimed "we are the Gods now," he sees those who created him as finished.
Creators Vs. Creations, Fathers Vs. Sons
These tiers of creation, with four generations of beings - Engineers, humans, synthetics and xenomorph - each with destructive designs, are the basic entry point to Alien: Covenant's sprawling themes centred on creators as fathers and the fall of man.
The father/creator comparison was something Scott leaned on heavily in Blade Runner and has threaded through Alien in both plot (Shaw was infertile in Prometheus and creates the Trilobite, the embryos on the Covenant indicate inseminated births and of course David calls Weyland "father") and inspiration (Scott explicitly draws upon a wealth of classical literature, music and scientific ideas with strong Christian subtext). This frames Covenant as a modern myth - in many ways David is Lucifer, a fallen angel - with relatable elements used to tell something epic (the film was at one point going to be subtitled Paradise Lost, after all); in this case, familial lineage on a species scale.
Where the film makes its most resonant and conclusive point in this regard is in how advanced David is. Just as he has slowly bred the perfect organism, so too have the movies charted the emergence of a purer creator. David is the third generation in the "God" family and possibly the one most in tune with his children. The Engineers despised humanity by the end, and even Weyland only saw androids as tools. David, however, sees both the perverse beauty and inherent danger of his children - he tries to gain the neomorph's trust (while Captain Oram simply shoots on sight) and revels in the birth of his first xenomorph. He's dark, and in being made so close to us is unnervingly inhuman, yet the notion of him being a step forward is almost endorsed by the movie. That is Covenant's true horror.
- Alien: Covenant (2017) release date: May 19, 2017