Saint's Halt - History: For the servants of the Emperor, each new contact with beleaguered regions in the Imperium Nihilus brought fresh news of falling or fallen worlds, continuing to far outweigh any tales of heroic resistance. In the blighted Chalnath Expanse of the northern Ultima Segmentum, scores of Imperial star systems were in the throes of uprisings and civil wars, scourged by fear-mongering prophets. Into these fractures, more than one xenos ideology seeped.Since the emergence of the Cicatrix Maledictum, the nearby watch fortress of Mortguard and its surrounding watch stations had weathered not only the ferocious Warp storms that had afflicted the surrounding sectors, but surges of xenos as well. Though many aliens had been wiped out by the birth of the Great Rift, many more were driven to invading new territories after losing their own, or were scattered into the path of weakened Human worlds by raging empyric tempests. Such threatening occurrences seemed to have afflicted the Chalnath Expanse.From its own network of astroduct splicing, comm shunts and informants, Mortguard identified a growing alien influence on the Imperial systems of the Chalnath Expanse. Its exact nature was revealed by Inquisitor Jazad D'ontor. The elderly Ordo Xenos investigator sent an encrypted missive to Mortguard's watch commander, Agathon. The Inquisitor's transcripts and vid-captures showed the hand of the T'au Empire at work. After worming their way onto poverty-stricken Frontier Worlds, the T'au had openly moved against several recalcitrant systems. On some worlds, D'ontor revealed, Astra Militarum regiments attempted to hold back T'au offensives, but other regiments were embroiled in vast civil uprisings of unknown origin. D'ontor had no answers as to how or why the T'au had appeared so far to the galactic north of their primary territory in the Eastern Fringe, but made clear that this was surely only a prelude to a full-scale invasion.The old investigator had intercepted T'au delegations making for the pivotal expanse worlds of Cestis and Saint's Halt. He had lost a sizable party of Inquisitorial Acolytes in the Arrajian System, too, and believed that all three locations faced being lost. Should they fall, the T'au would spread like a stain, corrupting the Chalnath Expanse from the inside out to threaten the vulnerable worlds at the southern rim of the region. From there, a major Warp route led directly to the Segmentum Fortress at Kar Duniash. The xenos could not be allowed to threaten so vital an Imperial stronghold.In response, Watch Master Agathon led three entire Watch Companies from Mortguard to the worlds of the Chalnath Expanse. D'ontor's evidence gave suggestions of possible T'au disposition, but the Deathwatch had deeper suspicions. The T'au, they believed, were not the only aliens in the expanse. Broken reports of mutants and religious sects, not to mention D'ontor's missing retinues, all reeked to Agathon of Genestealer Cult infections -- a foe the Deathwatch of Mortguard had fought before.The Deathwatch strike cruiser Void Sentinel, upon translation into the system, found the world already under siege by the forces of the T'au Empire. Native Planetary Defence Force infantry regiments of the Saint's Tidecasters fought alongside the battle-sisters of the Order of the Blue Robe, and Astra Militarum forces from the Riatov and Pennutsk Systems that had breached the T'au orbital blockade to reach the surface.From Void Sentinel's command throne, Watch Master Agathon conducted Mortguard's global campaign against both T'au cadres and Genestealer Cult uprisings. Hive Tor Saev burned, illuminating the southern pole. At Hive Delina, the Absolutis Arch was hung with bloody Loyalist corpses as their Genestealer Cultist murderers defended the city from T'au bombardment. Vast battle lines had opened up around every major hive city; Agathon concentrated his strikes against three.At Leonis Hive, the watch master directed kill-teams to sabotage a Shield Generator protecting the T'au flank from Riatov artillery companies. To Gedronis, he dispatched waves of Storm Speeders to cut off the xenos grav-tanks attacking the Gate of the Emperor's Vengeance, hoping to allow the Adepta Sororitas trapped there to break out. Mortguard's Watch Company Quintus in its entirety smashed into the T'au offensive outside the planetary capital city, Boran Prime. In a storm of special-issue bolter ammunition, cleaving blades and psychic scourges, the T'au buckled. The Deathwatch drove them back into the claws of xenophile cultists who declared themselves to be the Hivewyrm, forcing the two breeds of xenos to turn on each other.In orbit, Deathwatch reserves awaited the ambushes Agathon knew both faithless xenos species were capable of initiating. When the next one struck, he would be ready, as the war for the Chalnath Expanse ground on.