What's Up With David and Walter?
David's relationship to his creators/creation isn't the only core facet of his arc, however. He also forms a strong bond with Walter, the Covenant's resident synthetic. Unlike David, who was made to be as human as possible (this was heavily focused on in Prometheus' viral marketing), Walter is a scaled back model. This android refinement is already threaded through the Alien series, with the homicidal Ash in the first film replaced with the honorable Asimov-influenced Bishop in Aliens, but here it's at the forefront.
Underpinning the pair's interaction are some strong homoerotic undertones, best seen in the flute scene as part of their one-take introduction. While those sexual elements bring the Alien series full circle (the first film is all about male rape, right down to the phallic monster) there's a more complex power play here; David has clear feelings for Walter, but it's never not as a master.
The contrasts between the pair are evident from even before they meet. Obviously they're played by Michael Fassbender and thus identical, but they act in revealing, parallel ways; Walter is shown doing his daily routine on the Covenant wearing a hoody, while David is introduced an hour later wearing an Engineer cloak - one is a replicant of humanity, one is above us. This runs through their interaction with the question of love or duty; David developed actual feelings for Shaw, whereas Walter's caring for Daniels - sacrificing his hand to save her from a neomorph - never extends beyond a sense of duty.
The dichotomy comes to a head when David attacks Daniels, pitting the robots against each other. Physically evenly matched, Walter is seemingly able to get the upper hand, to which David gives him an offer straight out of Milton: serve in Heaven or reign in Hell.
How Did David Get Off The Planet?
The film cuts away from that offer and the next time we see either of the Fass-bots is when one is boarding the Covenant's landing module as it's about to take off. As presented we're meant to think this is Walter but, as his overly attentive demeanor clues audiences in, that isn't the case; David has bested the newer model, removed his own hand to make himself identical, and has through further duplicitous means finally got off the planet. He only reveals this fact to Daniels as she's heading into cryosleep - thus unable to stop him - and once she tearfully and reluctantly goes off he deposits two facehugger embryos in the ships depository, plotting his next step.
So what happened to Walter? It's not shown, but presumably David's offer of choice to Walter was merely an illusion. He was never beaten and simply wanted to see if his look-alike was capable of free thought - quickly offing him when it became apparent that wasn't the case. It's again that debate of love and duty, and of what it is to truly live. Walter clearly was just a robot, whereas David is - in a furthered dark twist - more evolved psychologically than we ever realized.
The distinction between the pair is solidified in the final moments with the handling of embryos. In the opening, Walter removes a damaged human embryo from containment and carefully disposes of it, whereas at the end David deposits his own meticulously-bred creatures that will corrupt the humans worse than anything before. He is creating a hell to rule over.
- Alien: Covenant (2017) release date: May 19, 2017