Vigilus - Neo-vellum: Vigilus' only moon, Neo-vellum, was an orb of white rock and swirling green gas storms. It was a stronghold of the Administratum -- that bureaucratic branch of the Imperium dealing with the coordination, analysis, assessment and deployment of information.Neo-vellum was a nerve centre of data for the Vigilus System, theoretically independent of the disparate Imperial factions on the planet, whose own agendas and bias might lead them to restrict or manipulate communications from the wider Imperium for their own purposes.Amongst the moon's acid swamps and emerald gas storms were built massive, hermetically sealed scriptorums that churned out logistical analyses at a slow but steady rate. Each was a messagecentre and an informational waystation, their legions of bent-backed auto quill scribes and lexicographers literally chained to their desks, allowed to slumber for a few scant solar hours per cycle beneath their wooden workstations before getting back to their tasks.Together, these stain-fingered troglodytes processed hundreds of thousands of data-slates, parchscrolls and data cylinders with every new day. Only a tiny proportion of these reached their intended recipients, but this wasof little consequence to the senior scribes -- provided the ink flowed, they cared not how or why.The normal protocol for despatching the message-scrolls produced by Neo-vellum's scriptorums was to encase them in ablative packets fitted with grav-chutes before firing them at the planet via hyper-pneumatic tubes. Each metal-cased scroll was launched on a route devised by the complex, cog-driven machine known as the Datasaint, a wonder of ancient technology that calculated the trajectory of the missive against the rotation and orbits of the moon and planet in order to target the recipient's exact position at the optimal time.Despite its fastidious computations, the Datasaint was so antiquated that its systems were corroded by millennia of entropy. As such, many of the messages sent out from Neo-vellum were wildly off-course and never reached their targets. Grav-chutes also frequently failed to deploy.More than one accident was caused by a stray message tube falling from the sky at great speed. In one famous case, the message was so on target and travelling at such a velocity that it killed the intended recipient instantly. The message tube itself was also destroyed on impact, and all record of its existence was swiftly eradicated by the Administratum -- but the tale lives on nonetheless.Neo-vellum was left alone entirely by the Ork invasion of Vigilus. Perhaps this was because the invaders sought richer pickings on the planet below, perhaps because the moon was simply on the other side of the planet at the time the Ork WAAAGH! hit home. Yet the satellite was not untouched by the scourge of the xenos.Hidden amongst the datastacks and grimoire nests of the Administratum's holdings, a secret cult thrived -- and in the attics of the monastic hab-blocks, strange creatures skittered from pools of darkness to slash apart those who dared to venture into their lair.The Cult of the Pauper Princes made it a priority to settle an infestation upon Neo-vellum shortly after establishing itself within the hivesprawl of Megaborealis. Ensrod Ghaul, the Primus of the brood sent to conquer the scriptorum moon, stowed away with a pair of dormant Purestrain Genestealers in the capacitor hold of the electro-freighter Zealous Blurt before the ship left for Neo-vellum on a routine resupply mission.Using a combination of forgery, charisma and murderous determination, he smuggled one container into the Scriptorum Primus district of Neo-vellum, and the other into the Stormwrack Citadel. As a result, two minor gene-sects propagated through the downtrodden ranks of Neo-vellum's workers.After the narrow escape of the quillslave Ghorrod from a xenos attack, and an anonymous message sent to the Inquisition, the Purestrain Genestealers themselves were hunted down and burned out by an Ordo Xenos purge, but their dark legacy remained on the moon.