Alien: Engineers, also known at various points during its development as Alien: LV-426, Alien: Genesis and Alien: Origins, was a 2011 script draft for a prequel to Alien, written by Jon Spaihts. The story eventually evolved into the spin-off film Prometheus. While the characters and overall plot of Alien: Engineers were retained in Prometheus, the script is otherwise quite different from the film that was eventually made. Most obviously, Alien: Engineers (as its various development titles suggests) acts as a direct prequel to Alien, taking place on LV-426 and setting up the events that occur in the original movie. It was followed by the first draft of what would become the final Prometheus shooting script, written by Damon Lindelof.
Three Engineers land on a lush planet. One of the individuals eats a piece of ceremonial cake, which boils into a swarm of small scarab-like insects that dissolve him. On a nearby mountain, a primitive human woman watches the remaining Engineers depart aboard their ship, as one of the scarabs bites her on the back of the neck, infusing her with the DNA of the dead Engineer.
An indeterminate amount of time later, Doctor Jocelyn Watts and Professor Martin Holloway are excavating underwater using a pair of submersibles. They uncover a large obelisk covered in alien text. Upon returning to their parent vessel on the surface, they study scans of the obelisk and discover a set of stellar coordinates among the text covering it. They take this information to a large Weyland Industries space station in Earth orbit, where they meet with Peter Weyland. Weyland agrees to fund a scientific expedition to follow the star map, on one condition — while Watts and Holloway will get the scientific credit for any discoveries they make, any alien technology they find will go straight to Weyland Industries. Having been turned down by every other backer, Watts and Holloway agree. Weyland's director of operations, Lydia Vickers, and a highly advanced prototype android named David, also accompany the trip.
The team travels to the system indicated by the obelisk aboard the Magellan, commanded by Captain Janek. Janek, along with most of his crew, are skeptical and anxious about the mission, but have agreed to take part on the promise of triple pay. The Magellan reaches its destination, Zeta II Reticuli, and soon finds evidence of potentially non-natural structures on a moon designated LV-426. The team discovers several pyramids on the surface, including a large complex inside a series of regular craters linked by deep trenches, suggesting artificial construction. Janek sets down and the science team move out in vehicles to investigate further. They enter the largest, central pyramid and begin mapping the structure with remote drones. When they are startled by a holographic recording, two of the team, Fifield and Millburn, elect to return to the ship. The rest of the team discovers terraforming equipment at the center of the pyramid, as well as a pile of ancient, eviscerated Engineer corpses.
A satellite the Magellan left in orbit detects a large storm front moving with the moon's sunset, and Janek orders everyone back to the ship. They barely make it; Watts is almost blown away by the savage winds but David rescues her. Once on board, they realise Fifield and Millburn never returned. They contact the men by radio, and find they have become lost inside the pyramid. They have plenty of supplies, and Janek tells them to hold out until they can return after the storm has passed in the morning. The team on the Magellan celebrate their discovery. Afterwards, Watts and Holloway autopsy an Engineer's decaying head that they recovered from the pyramid.
That night, Millburn is attacked by a centipede-like creature and killed, whilst Fifield is subdued by a swarm of the scarab-like insects. The following morning, Vickers awakens a team of mercenaries secretly stowed away aboard the Magellan and places them in charge of the expedition. The team returns to the pyramid to try and locate the missing men and continue their exploration. Under Vickers' orders, several of the scientists begin disassembling the terraforming equipment so it can be returned to Earth for study. Watts and Holloway discover more dead Engineers, each with their chest burst outwards, but Holloway falls down a shaft and gets separated from the rest of the team.
Janek discovers Millburn's corpse and orders his crew back to the ship, although Vickers' mercenaries and several scientists remain to deconstruct the terraforming machine. Watts and David also stay behind to find Holloway. They eventually find him wandering aimlessly with no real memory of what happened to him; they take him back to the ship. Once there, Watts and Holloway make love, but a creature suddenly bursts from Holloway's chest, killing him. The white, boneless alien creature quickly escapes into the Magellan's ventilation system. The crew begin searching the ship, while Watts returns to the pyramid, following the location data recorded by Holloway's spacesuit, hoping to find out what happened to him. She finds that he was attacked by an octopoid creature that latched onto his face. As she moves on, she encounters David aboard a large Engineer spacecraft hidden underground. David reveals that the ship was headed to Earth with plans to wipe out humanity using genetically-modified, weaponized versions of the creature that attacked Holloway. However, the creatures got loose and wiped out the crew before they could carry out their mission. In a large chamber filled with leathery eggs, David attacks Watts and allows one of the weaponized creatures — a Facehugger — to subdue her.
When she regains consciousness, Watts just barely makes it back to the Magellan and climbs into a Med Pod. The Chestburster within her bursts from her chest in the middle of surgery to remove it, and Watts dies. However, the Med Pod's systems manage to save her life and repair the damage. When she wakes, she sees the now fully grown Xenomorph attack and kill one of the crewmembers as he enters the room, but she manges to shoot the creature before it can turn on her.
Watts discovers that several of the crew have been gruesomely killed by the creature that came from Holloway in her absence, which is now fully grown and hiding on the lower decks. She informs the survivors of the Engineer ship and its mission to wipe out humanity, a mission that David is now attempting to resume. With no alternative, the survivors elect to try and stop him while Janek stays behind to try and fix the Magellan, which David has sabotaged. Aboard the Engineer vessel, the remaining crew and mercenaries confront David as he revives a final Engineer from hypersleep. The Engineer decapitates David and slaughters most of the team, but Watts survives while Vickers escapes with the leader of the mercenaries, Shepherd; Vickers and Shepherd encounter the now mutated Fifield as they flee through the pyramid and are killed.
Watts returns to the Magellan and kills the creature that emerged from Holloway just as it prepares to attack Janek. They see the Engineer ship leave and set off in pursuit, but are unable to catch up with the much faster Engineer vessel. However, when the Engineer pilot is killed by a Chestburster that erupts from his chest, his ship falters, allowing Janek to crash the Magellan into it, destroying the Magellan, killing Janek and fatally crippling the Engineer vessel. Watts jettisons from the Magellan's wreckage in an escape pod. Back on the surface, she is attacked by the huge Ultramorph that emerged from the Pilot, but she eventually kills it with a circular saw.
In the aftermath, Watts is contacted by David, who tells her that it is likely the Engineers will come to investigate. As she considers this, the pyramids on the moon transmit a distress signal into space.
While Alien: Engineers bears many similarities to Prometheus, the script was heavily revised before filming began. The most major alteration made was the removal of the screenplay's prequel element, shifting the story to the planet LV-223 and turning the film into a stand-alone movie that takes place in the same universe as Alien, but is not directly connected to the earlier film. This disassociation also entailed the complete removal of the Xenomorphs from the story. Instead, the biological weapon being used by the Engineers in the film became the black liquid (which itself evolved from the swarm of black, scarab-like insects that appear in Spaihts' script). Despite these changes, the key plot thread of Spaihts' screenplay — the Engineers shaping ancient human evolution before later electing to destroy us, only to succumb to their own destructive creations before they could carry out their plan — carried over into the finished film.
Interestingly, Peter Weyland's company is known as Weyland Industries in Spaihts' script, as it was in Alien vs. Predator. In Prometheus, the company was instead called Weyland Corp. There are numerous other name differences as well — the USCSS Prometheus is called the Magellan, Elizabeth Shaw is called Jocelyn Watts, Holloway's first name is Martin, and Vickers' first name is Lydia. The scenes set aboard the Weyland space station at the start of the screenplay make it clear technology has not yet reached the level witnessed in Alien — the station itself consists of a giant ring that can only generate gravity through its rotation (although strangely a lack of gravity is never said to be a problem aboard the Magellan), while David mentions that Weyland Industries' first terraforming project, on Mars, is running into teething troubles. Technology in the final film seems far more advanced in comparison.
While it features the traditional Xenomorph from Alien, Spaihts' script also introduces new variations of the species with new attributes or abilities. During the story, David makes it clear that the Xenomorphs seen in the Alien films are not naturally-occurring organisms, but rather biologically engineered weapons of war, created and/or modified for purpose by the Engineers. David goes on to imply there are other variations of Xenomorph designed for specific purposes, variations which have yet to be seen. The Alien has long been theorized to be an unnatural creation, a concept endorsed by Alien director Ridley Scott, but the idea has never been officially confirmed in the films.
Perhaps the most notable of the new Xenomorphs described in the script is the creature born from Holloway on board the Magellan. The script later implies this so-called "Beluga-Xenomorph" may be the progenitor of the Xenomorph species, or at least an earlier iteration of it, stating that the Eggs and Facehuggers discovered by the crew of the Nostromo in Alien are "an evolution" of the molluscoid eggs and Octo-Facehugger that impregnates Holloway. The Beluga-Xenomorph is said to be white in color, as opposed to the predominantly black Xenomorphs, and is able to reshape its malleable body to squeeze through small openings.
The screenplay also features a Jockey-Xenomorph or Ultramorph, the existence of which was implied in Alien when Dallas, Kane and Lambert discover the Pilot's corpse aboard the derelict, its chest burst open. Spaihts describes the Ultramorph as "dark gray, armored, lethal... more hideous than any [Xenomorph] we've seen". The creature grows even more rapidly than typical Xenomorphs, at one point visibly increasing in size as Watts watches it feed on the rotting Engineer head recovered from inside the Engineer facility.
- The large black obelisk Watts and Holloway unearth in the opening scenes and the ring-like space station where Watts and Holloway meet with Peter Weyland both bear remarkable similarities to comparable devices in Stanley Kubrick's seminal 1968 film 2001: A Space Odyssey.
- At one point, Holloway mentions "Prometheus bringing fire from heaven" to the crew of the Magellan, unintentionally foreshadowing the title and theme of the film that was ultimately made.
- The script states that the Magellan lands on LV-426 on December 31st, 2172. However, the Nostromo supposedly lands on the moon in 2122, which is 50 years earlier.