Kill-team Cassius - History: Not for nothing is the name Ortan Cassius inscribed upon the umbrite Black Charter in the depths of Talasa Prime's archives. Centuries ago, he and a kill-team delved unauthorised into a deadly enigma; they would be the first to bring the sickening cycles of the Genestealer Cults to light for the Imperium.What became known as the Ghosar Quintus Anomaly began in 680.M41 with a determined Ordo Xenos investigator. Inquisitor Chaegryn vanished after srutinising a disquieting religious deviancy within the honeycombed Delverworld of Ghosar Quintus in the Segmentum Ultima. The Inquisitor's initial findings spoke of strange icons, scrawls of a "four-armed Emperor" and evidence of alien worship. His final contact, however, declared there to be nothing amiss and recommended no further investigation. Yet Chaegryn and his accompanying team of Tempestus Scions were never seen again.Suspecting alien mental influence on the investigator, the Ordo Xenos requested the aid of the Deathwatch Chapter. Whatever could overcome the iron fortitude of an Inquisitor threatened the sanctity of Mankind's very future.Chaplain Ortan Cassius, seconded from the Ultramarines Chapter, commanded the nearest Deathwatch forces. he divided his warriors. Half continued their extant mission with him. Five others formed Kill-team Excis, under the command of Thaniel Ectros of the White Consuls, whose mission it was to secure the missing Inquisitor, either returning him or his remains to the Inquisition. Yet Kill-team Excis, too, were swallowed by whatever mystery hid on Ghosar Quintus.Cassius vowed to discover what had befallen Kill-team Excis. Not only had he sent them to their fate, but there was something on Ghosar Quintus that defied the Imperium's greatest warriors. The Chaplain's desire to see such a challenge punished led him to assemble a kill-team without his watch commander's approval, to being the Emperor's vengeance to whatever lurked there.Cassius had fought Genestealers before with the Ultramarines, before his induction into the Deathwatch. From the sparse evidence the Inquisitor had originally submitted before his disappearance, Cassius already suspected that these xenos were involved somehow in whatever was affecting the Delver World.Following Cassius to Ghosar Quintus was Vael Donatus, a superb shot also hailing from the Ultramarines. Donatus was regularly given subcommand of the kill-team by Cassius over the more experienced Zameon Gydrael, a hooded close combat duellist. The erstwhile Dark Angel had little time for boasters. He did nothing to hide his dislike of his teammate Drenn Redblade of the Space Wolves, a feeling the reckless but gifted warrior joyfully shared. Alongside them was Rodicrus Grytt, an indiscriminate heavy weapon specialist of the Imperial Fists and the calculating analyst Ennox Sorrlock, an Iron Hand sworn to the Deathwatch for an extended mission. There was also Garran Branatar, a fiery Salamander burdened with the guilt of a battle-brother's sacrifice to save his own life.Extended the role of the hunter by the Chaplain were Jetek Suberei and Jensus Natorian. The biker Suberei was a White Scar and a force of unbridled destruction. The Blood Raven Codicier Natorian was a powerful psyker, recognised by Cassius as much for his finely tuned psychic senses as his lightning fast bladework.While both of these warriors struck from above with their Jump Packs, the sinister Edryc Setorax of the Raven Guard often attacked from the shadows, while humble Antor Delassio of the Blood Angels was a paragon of Imperial rectitude.Ghosar Quintus had been cored in ages past to plunder its predigious mineral wealth. Over the centuries, the planet's ruling Trysst Dynasty had improved the mining yield. The largest mine wirking, known as the Great Pit, had been extended and strung with so many structures over the generations as to form an entire hidden subterranean world.Descending into the Great Pit, the Chaplain and his kill-team were stalked by the Tryysts' mining clans. The Veterans saw that they were not sun-starved labourers, but xenos Genestealer hybrids in thrall to pure-blooded Genestealers. The deeper they fought, the more horrific the abhorrent genetic meldings of Humanity and Tyranid they discovered. In the deepest depths of the Great Pit, Cassius discovered and faced down the cult's founding Genestealer Patriarch, his Rosarius'  projected energy field saving him from its monstrous claws.Kill-team Cassius ultimately survived and discovered the Inquisitor's Servo-skull with evidence that proved Chaegryn's initial findings of a xenos infestation. What Cassius had revealed to the Imperium was no isolated nest of Genestealers, but the horrific reproducitive cycles through which they spread: from settlement to settlement, from planet to planet.Most shocking of all was the damning evidence in the mining cult's shipping holographs. Under the guise of industry, the xenos-tainted Trysst Dynasty had spread its curse across not only the Ghosar System, but throughout the sector and perhaps across half the galaxy. The implications were staggering; the scale of the xenos threat was unprecedented.Only when the First Tyrannic War began several solar decades later after the arrival of Hive Fleet Behemoth did it become clear that Genestealer infestations represented only the first step in the Great Devourer's plan to consume the galaxy.In breaking open the horror on Ghosar Quintus of the Cult of the Four-Armed Emperor, a wide-ranging, insidious genetic contamination of Humanity had been uncovered and a new war against the xenops threat begun. It was a war Cassius vowed to win.