Pyrathas - History: In a galaxy plagued with oddities and anomalies, Pyrathas nevertheless deserves mention. Although ignored by the Humans of the ancient Jericho Sector, this world has become a lynchpin of the Iron Collar and a vital resource for the crusade's Acheros Salient.Pyrathas was discovered almost by accident, in the second year of the Achilus Crusade. As the crusade fleets advanced into what would become the Iron Collar, Explorator ships ranged ahead, cataloguing new worlds for conquest.When the frigate Omnissiah's Dispatch dropped out of the Warp on the edges of System Designate 018-9J0-5B, they found a star system dominated by a fierce, blue-white supergiant star.The fury of the star's heat had long ago blasted every planet to half-molten cinders -- save one. An immense jovian-type gas giant, Pyrathas Majorus (itself a smouldering brown dwarf star) whipped around the supergiant in a tidally locked orbit.Tucked safely in its penumbra, a single moon was likewise tidally locked, heated by the embers of its planet, and possessed of a breathable atmosphere. The captain decided to investigate.The moon that would become known as Pyrathas was a harsh, inhospitable place. Low gravity had created a world of towering cliffs, high mountains, and deep fjords. The constant gravitational stresses generated massive volcanoes, leaving the atmosphere a grey haze, and life had not evolved past hardy lichens and mosses.At first glance, Pyrathas had nothing useful to offer the crusade. However, Lord Militant Tiber Achilus and his staff saw an opportunity in Pyrathas -- a shielded anchorage, protected by the fury of its sun, and ideally placed between the Fortress Worlds of Karlack and Hethgard.On Achilus' command, Pyrathas became the latest link in the rapidly forming Iron Collar. The rough terrain proved ideally suited for fortifications. Legions of Adeptus Munitorum convict-labourers capped the mountains with adamantium bastions and dug extensive launch bays for Lightning and Thunderbolt fighters into the cliffs.In areas of active volcanism, they sank deep geothermal shunts to power concealed Defence Laser batteries. Meanwhile, the Adeptus Mechanicus constructed large orbital docks around the moon to service the needs of the myriad warships that would soon come.Within a single Terran decade, Pyrathas had been transformed into the Iron Collar's second largest anchorage for the Imperial Navy, surpassed only by Karlack itself.Unlike the majority of the other Fortress Worlds, the Navy took some pains to conceal Pyrathas' exact location from its adversaries.Pyrathas' coordinates are considered a Magenta-level secret, and the signs and counter-signs allowing a vessel to enter weapons range are only possessed by the pilots of system defence monitors who wait on the edges of the star system to escort arriving vessels.Of course, the Navy realised that it could not maintain Pyrathas' location as a secret forever, and also installed scores of orbital laser and torpedo batteries.In the years since, Pyrathas has become a valuable fortress in the Iron Collar. When the fleet of the Orpheus Salient succeeded well beyond the crusade's plans, Pyrathas served as a transit centre for Astra Militarum regiments and military supplies retasked to the nearby Acheros Salient.When the tendrils of Hive Fleet Dagon began to curl around the crusade forces in the Orpheus Salient, Pyrathas saw its role reappraised. It remained a transit centre, but the flow of troops and materiel reversed to staunch the dangers of Dagon.Certain crusade commanders -- Pyrathas' Captain Skor among them -- have privately voiced the opinion that should the Tyranid hive fleet defeat the crusade and consume the Jericho Reach, Pyrathas may prove a final Imperial refuge against the swarm.The furious glare of the blue supergiant makes approaching the anchorage without the protection of Void Shields suicidal, and thus far the Tyranid Hive Ships encountered do not have a suitable alternative.These commanders argue (amongst themselves, where their thoughts will not be labelled seditious by the Commissariat) that should the crusade falter and fail, what Astra Militarum and fleet elements that could not be evacuated through the Warp Gate should be pulled back to Pyrathas, where they can wait for an Imperial counter-offensive.Some even more pessimistic voices argue that the more likely outcome is that the Imperium would attempt to destroy the Warp Gate. Although this would strand the forces remaining within the Jericho Reach, they postulate that the Tyranids would wipe out the Chaos and T'au-held worlds, leaving Imperial forces free to "pick up the scraps" after they passed.What none of these individuals speak of, but all fear, is that the supreme adaptability of the Tyranids may lead to some new way for them to endure the glare of Pyrathas' sun, and consume the world anyway.