The Ephesian Schism
The Ordo Xenos, together with the Ordo Malleus and the Ordo Hereticus, is one of the primary sub-divisions of the powerful and secretive organisation known as the Imperial Inquisition. The Ordo Xenos is served by its Chamber Militant, the Deathwatch Space Marines, who draw on Veteran Astartes from Chapters all across the Imperium of Man to form the Deathwatch’s Kill-teams and destroy the many foul xenos threats to the survival of Mankind.
Armed with the best human and alien technology available, extremely knowledgeable about their foe, and filled with the xenophobic hatred for non-human species that drives so much of Imperial culture since the Horus Heresy, the Ordo Xenos can respond to any alien threat.
Their tactics vary depending on the situation and the level of alien taint revealed. Where the threat is subtle, they will use guile and stealth, wielding their power as if it was a scalpel used to cut out a growing malignant cancer. When the alien menace is great, the Inquisitor can commandeer the aid of entire regiments of the Imperial Guard and the Deathwatch.