Vejovium III is a Civilised World in the Pahr Sector of the eastern Segmentum Obscurus that has been a major exporter of bio-alchemical and pharmaceutial products for the Officio Medicae of the Administratum for many centuries. The planet was long characterised by an industrial nobility that engaged in medical experiments on its own people to enhance their own control.
The unexpected arrival of Purestrain Genestealers on the world opened vast new areas of experimentation for the nobility who ruled the world's medifactoria complexes. Seeking biological perfection and perhaps even immortality, these researchers willingly hybridised the human genome with that of the Genestealers, ultimately creating an "artificial" Genestealer Cult known as the Twisted Helix which now is the de facto ruler of the planet.
The shadowy researcher who led these initial experiments was known only as the "Prime Specimen," though whether this is a reference to a Genestealer Patriarch remains unknown.
The Twisted Helix now spreads their unique version of the Genestealer's Curse to other worlds through the propagation of its biomedical products, all of which promise their users extended life and enhanced health while actually infecting them with Genestealer DNA.
The Cult of the Twisted Helix's original site of infestation is Vejovium III, deep in the east of the Segmentum Obscurus; the planet is technically a Civilised World, but it was long ago overtaken by the industry of the macro-alchemical distilleries that manufacture its exported medicines.
So influential have these complexes become -- and the dynastic corporations that rule over them -- that everywhere the Vejovian skyline is ridged with enormous medifactoria. These appear, when viewed from the hive aristocracy's spires, like the laboratory of some godly sage -- spiral glass pipelines and chimneys belch strangely coloured smoke alongside vast alembic structures and cooling towers. Given the influence they have over the lives and even anatomies of the populace, the divine comparison is an apt one.
The war leaders and Biophaguses of the Twisted Helix think of themselves as a new breed of god-like being, their clay the flesh and blood of those around them, and their creations a blend of human, alien and voidstuff. These they see as nothing more than experimental subjects, and every skirmish, hostile takeover and even large-scale uprising purely another test bed from which to draw firmer conclusions about their experiments thus far.
They have created works of mad genius in their quest for the perfect life form, yet seek daily to surpass them, for nothing short of galactic domination will satisfy the power-mad maniacs who rule the cult's medifactoria behind a façade of intellectual curiosity.
Vejovium's rulers long ago cracked the secrets of dulling the human mind. After the costly Doxencrafter Rebellions of the late 38th Millennium, the Planetary Governor commissioned an inhibitory chemical that could be mixed into the food paste and corpse-starch of his citizenry's diet. The spread of this potent chemical saw the populace rendered docile, even bovine in its apathy to anything but the strongest stimulus. Though those visitors who saw this for the horror it was did everything to bring some manner of justice against the rulers of the cult, they were always undermined, kidnapped or shouted down by those with controlling interests in the planet's industrial fortunes.
With Vejovium supplying so many of the medi-packs, Apothecarium supplies and void sickness pills to the Imperium's military bodies across the Pahr Sector, the investigations never plumbed the depths that would have unearthed the conspiracy spreading at the heart of the planet's fortunes.
Ironically, it was this deadening of the psyche that was to prove a temporary salvation for Vejovium's people. When a clutch of Purestrain Genestealers, intended as fodder for more extreme experimentation, reached the planet via the Imperial black market, the first of the stevedores to meet one of the Tyranid vanguard organisms face-to-face was no easy prey for his wouldbe corrupter.
His narcotically-dulled mind proved resistant to the strange hypnotic effect of the Genestealer's psychic aura -- and, on instinct, closed the airlock in which the beast and its kin lurked, slamming the reinforced door shut just as the creature's ovipositor darted out to graze the glasscrete.
The incident was reported to the on-duty overseer, of course, and from there the message reached the highest hive city spires. At a worryingly steep cost in the lives of their "volunteers," the leaders of the industrial cult laid low their Genestealer prisoners -- after assailing the airlock with radiation baths, poison gas, sonic destabilisers, and even acid mist they eventually resorted to a hail of bullets that not even the Purestrains could survive. They subsequently dissected the very xenoforms that had sought to infect them.
Over the course of hundreds of exhaustive experiments, the medical overseers of Vejovium III learned how to extract the pure germ-seed of the Purestrain from the cellular genomes of those who have been blessed by the Genestealer's Kiss. At the behest of the shadowy individual known only as the Prime Specimen, likely the cult's Genestealer Patriarch, the implications of this discovery were exhaustively researched.
It was eventually concluded that they stood on the threshold of a new evolution -- that the xenos gene-pattern was the path to true biological perfection, and perhaps even immortality. Under strict test conditions, the aristocracy of Vejovium injected the stuff of the alien into their veins, and began their transformation into something resembling Neophyte Hybrids.
In essence, though they had at first evaded the curse that sought to infect them, the lords of Vejovium instead voluntarily started their own transformation into alien monsters at a far later stage of the standard Genestealer brood cycle. Sure enough, after many hideous by-blows and aborted experiments, they birthed a new clutch of Genestealers with which to further their agenda -- albeit a brood given life in the sterile tubes of a secret medifactoria rather than the incubatory anatomies of infected hosts. These in turn infected new infestation sites, and the Vejovians slowly began to resemble a Genestealer Cult like any other.
So it was that the Genestealer Curse took hold upon Vejovium through a new and disturbing vector. Obsessed with their discovery, the Prime Specimen and his peers widened their research time and time again, venturing into the most bizarre territory in their search for new bioforms that would reinforce their delusions of godhood. They became convinced that to seed their concoctions throughout the people would be to secure their undying loyalty, even worship.
Subsequent experimentation led to methods of incorporating the pure Genestealer germ-seed into the curative syringe vials that form a major part of Vejovium's interstellar medical exports -- and from there, into the veins of millions of unsuspecting Imperial citizens. Every recipient is rendered susceptible to the brood curse that is sure to follow; those with constitutions stalwart enough to resist are often given compulsory vital supplements in pill form, and later given reinforcement via a midnight visit from one of the cult's "independent vectors" -- Purestrain Genestealers.
- Codex: Genestealer Cults (8th Edition), pp. 30-31
- Codex: Genestealer Cults (7th Edition), pp. 19