The Heart of Blade Runner is the story of the Replicants' return to Earth in order to meet their maker and obtain more time, since they were constructed with only a 4-year life-span.
So what is the Heart of Prometheus?
While Prometheus mostly follows Elizabeth Shaw and boyfriend Charlie Holloway, that's not the Heart. Why? Because their story is the byproduct of and subjugated by another story (as Deckard's was). That of Peter Weyland.
Peter Weyland is the reason this trip to LV-223 is taking place. It's his money. And he brings Shaw and Holloway and the rest of the scientists along to make sure he gets to meet the Engineers.
Because Weyland is dying and doesn't want to be. He's hoping if the Engineers made humans they will be able to give him more time.
Sounds familiar, right?
There are certain twists on Blade Runner. Weyland isn't an android. In Blade Runner, humans are the Creators, the Almighty, but in Prometheus we're in the position of the Replicants. We're something that was created. Thus, in Blade Runner we're Dr. Frankenstein dealing with the "monster" we've created. In Prometheus, we're the monster.
Which is interesting. We can sympathize with the Replicant plight, but we can't...know what it's like to be an android with a 4-year life-span. We're not androids with 4-year life-spans. So like with the novel Frankenstein, we're sympathizing and trying to understand what it's like to be the monster, but...we're not science experiments.
The premise of Prometheus is that WE ARE science experiments.
This is very interesting to me. Especially when Weyland and Shaw try to talk with the Space Jockey. Imagine everything we know about human existence. How far we've come from cave people to building fucking space ships traveling through the cosmos. We live rich intellectual and emotional lives. Love, anger, joy, grief. Smiling. Laughter. We create art. We do benevolent things for one another. We have culture and history and holidays. And here we are, encountering the beings who made us. And the Space Jockey looks at us, can't understand us, then decides we're horrible and needs to kill us. IT HAS NO IDEA HOW MUCH WE FEEL AND LOVE. And yet it decides we're entirely expendable.
This is the same plot that's going on in Blade Runner. The Replicants love and experience and yearn, more so than we could imagine. Which is why they feel so cheated. 4 years. That's it?
Deckard goes from retiring/murdering Replicants as his job to running away with one (we're ignoring the fact Deckard is probably a Replicant himself). When Roy Batty sits on the roof, when he holds the dove, when he spares Deckard, and gives his speech about his experiences being lost in time, we see how human Roy is. He's still a murderer. But...are the androids really as expendable as we thought they were? Don't we owe them more? What kind of creator are we? How can we expect our creator (if we have one) to love and take care of us if we look down on what we've created? Does our creator even know we exist? Does our creator understand the depth of our soul?
Prometheus answers these questions Blade Runner generates with a resounding "no" (one conveyed in the body language of decapitation and physical assault). The Space Jockey sees us, understands what we are, and tries to kill us.
This gets at a subtle arc in the movie. The humans look down on David, the android. They use his skills (I like to think they admire him at least for his skills), but they talk to him as a lesser being. Basically, they treat him like shit. Even Shaw says something like "it's a good thing you don't feel" or "it's good you don't have a soul". What's obvious to the viewer, and not to the characters, is how much David does feel (and how it hurts him she would say such a thing). He's more human than the humans are giving him credit for. When the Space Jockey denies humans, we (humans) are put into the same position as David: a thing misunderstood by its creator.
Which brings us to the conclusion of both films.
Blade Runner: Deckard and Rachael run off together, with Deckard having a fresh appreciation of the depth of emotion that exists in a Replicant. The Replicants are, in a sense, redeemed. Or at least elevated. They've earned Deckard's respect. A sort of de-segregation has taken place. He and Rachael are now one-and-the-same. And this is true whether Deckard is a Replicant or not, because whether or not Deckard is or isn't a Replicant isn't what's important. The eradication of Deckard's prejudice against Replicants is.
Prometheus: Shaw and David fly off together, with Shaw determined to figure out why the Engineers are trying to kill humans, why they think humans are so...disposable. Which means Shaw and David are now one-and-the-same. Both are thought of by their creators as being less than what they really are. Humans are kicked firmly in the confidence--are, like David, misunderstood. We are not elevated or redeemed.
And the Maker in each movie is killed. Roy crushes Tyrell's face. And Shaw passive-aggressively kills the Space Jockey by allowing the alien out of the room.
And that xenomorph thing brings up an interesting question.
If Shaw gave birth to the alien, than are humans the creators of the xenomorphs/Aliens? If so, then Alien takes on the same theme of "meeting and killing your maker".
If we consider the Space Jockey the creator of the xenomorph, than Alien is a sibling rivalry.
I'm not totally happy with Prometheus, especially since it is, to me, a less-great version of Blade Runner, but I do think this "Humans and Xenomorphs are basically siblings"/"Humans are basically the parents of Xenomorphs" thing adds some interesting depth to Alien.
On a side note, if you think about it, Gladiator is basically the same "meet and kill your maker" plot. General Maximus Decimus Meridius is "made" into a gladiator thanks to the actions of Commodus. Maybe that's a stretch? Maybe not.
Also, of note: in both Blade Runner and Prometheus the Heart of the Matter ends, and our protagonists survive the drama of others. So Deckard and Shaw are each free to do as they will. Where Deckard learns to make the most of his time, Shaw learns...nothing?
Prometheus is a bleak fucking flick.