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Vulcallus was once a flourishing world, prized by the Imperium. It held vast mineral wealth, and boasted of numerous munitions factories that fueled the Emperor’s Great Crusade to bring all of humanity into his fold. Despite their loyalty and value to the Emperor, the Lords of Vulcallus were forgotten when Horus turned his back on his father and chose the path of chaos.
Hanging in what was now an inaccessible corner of the Segmentum Obscura, Vulcallus was all but erased from memory during the long years of The Great Scouring, when the the Imperium of Man waged that endless war on the traitor legions.
Soon, rot set in. Without guidance and supply from the Imperium, Vulcallus had no recourse against a plague of fungus that began to spread across its continents. It came from nowhere, growing its tendrils into everything it crossed and filling the sky with spore clouds that traveled on the wind. Crops wasted away, famine raged, and chaos reigned. It was a dark time for the people, seemingly outcasts—brushed away like chaff before the Emperor’s threshing rod—and those dispossessed peoples steadily turned to the Dark Powers, as if compelled by fate.
Since those distant days Vulcallus has festered, both biologically and spiritually. Seeing what ruin the plague world might wreak on nearby star systems in future centuries, multiple Astartes chapters have grown concerned with its presence and have sent vanguard forces to analyse its threat. Additionally, lured slowly towards Vulcallus by the spore clouds sowed in the wake of its orbit for the last thousand years, xeno races have been drawn to the planet’s mysteries. Lastly, rogue Traitor Marines have sent in their own reconnaissance teams to assay the wonders of a world so blessed by Chaos.
Now which of these intruders, if any, will survive the encounter with Vulcallus?