Medusa - The Medusan Inheritance: A cold, barely life-sustaining planet several times the size of Terra located in the outer darkness of the Segmentum Obscurus, Medusa is the fourth world orbiting a supergiant star known in the ancient Terran astrocartographic charts as Sthenelus.In the lost days of Human might during the High Age of Technology, the ancient lore of the Mechanicum holds that Medusa was a world deemed of great importance, its depths mined for rare core-strata deposits by vast, tireless robotic engines and its riches guarded jealously from rival species by sleepless guardians. So it was that when the shadow of the Age of Strife fell and all was given over to bloodshed and anarchy, Medusa, unlike so many other lost domains of Mankind, was not forgotten by Mars nor on Old Earth but remained a legend of glory and wealth.The exact origins of the Human presence on Medusa is uncertain, and genetic evidence reveals that it is most likely to have been the result of several different survivor groups, some perhaps dating back to the colonists of the Age of Technology, others almost certainly the stranded remnants of star-wrecks and pre-Navigator sub-light sleeper ships launched by the Mechanicum during the Age of Strife to find this fabled world.These antagonistic survivor-waves of the population, confronted by the near-unlivable surface conditions created by the planet's harsh climate, violently unstable geology and lack of native flora and fauna, devolved into techno-barbaric savages. Further forced into a nomadic existence by a constantly shifting landscape where mountain ranges and seas could be forged or unmade in a season, the Medusans retained by rote a degenerate superstition-ridden faith based around the dim memories of the Cult Mechanicus, a vastly uneven trove of weapon-crafting, cybernetic and mechanical lore, but lost all semblance of civilisation beyond that of the basest hunter-gatherer.They formed into mobile, semi-tribal clans, the largest of which were centred on massive fortified land-crawlers (based in part on ancient STC designs for mining and harvesting engines), from which raiding and foraging parties set out to claim meagre resources and make ceaseless war on the other clans. They were a savage and unforgiving people; slavers and killers to whom the battle to survive was an unrelenting, bloody struggle in which only the strongest prospered.As the Imperial expeditionary fleets of the Great Crusade broke out of the Segmentum Solar in the late 30th Millennium, following the Warp-tides to the edges of the uttermost unknown, famed Medusa was high upon the Crusade's list of targeted goals, although its exact position was now uncertain. When a Mechanicum Warp-runner, more than a standard year out and alone in the darkness ahead of the main fleets first broke from the Empyrean into the Sthenelus star system and rediscovered Medusa, the sight that greeted them was both unexpected and bleak.The whole range of the system's inner sphere was littered with the debris of shattered voidships, fogs of silicate dust, dead hulks and fractured planetoids, all as cold and silent as the grave. Around Medusa itself, the legendary Telstarax -- the colossal planet-circling orbital ring-station which had girthed Medusa in the Dark Age of Technology to plunder its riches and carry them aloft into space on immense tether-conveyors -- was a tortured ruin, much of it having fallen back to the planet with no doubt catastrophic force. As the Warp-runner closed with the planet, it found itself beset by many dangers, from sudden ionic squalls to erratically functioning mines and autonomous weapons systems -- ancient, but still deadly -- hiding in the debris fields. Wounded, it still went on, lured by the myth of Medusa.Reaching close orbit, the Warp-runner scanned through the thick and shrouding atmosphere, casting the hard electromagnetic glare of its auspex on the planet below. It found a world almost lifeless and shuddering with dangerous and near-constant tectonic instability. From the Warp-runner's high vantage point, it could see the worm-coring of played-out mine workings deep beneath the sheet ice and tundra, Medusa's cold ground further riven with immense scars and impact craters, although whether from sky-fallen debris from the Telstarax ring or some ancient orbital bombardment, it could not ascertain.It also heard signals; the ghosts of vox-traffic in half-familiar tongues and distorted tech-cant codes, and alongside this its auguries registered the scattered heat-bloom heartbeats of crude but massive thermic reactors at the heart of huge machines crawling across Medusa's broken lands, and within these the sparse Ӕtheric signature of Human life.The glory of Medusa in the Age of Technology had fallen into a wreckage of devolved ruins and barren rock, its wealth spent and ripped from it during the Age of Strife. But amidst the emptiness and despoil, the Warp-runner's deep searching of the radiation and signals found something else, something unique that all its kind had been tasked to quest for -- a treasure beyond price.It found a primarch.