Despite the myriad creatures of the Warp that swim through the Ether, the greatest threat to Mankind comes from within; from those who would consort with the Ruinous Powers or utilise the fell sorceries that can be wielded by tapping into power of the Warp. Even a slight lapse in the harsh regime of disclipine and vigilance imposed by the Adepts of the Imperium results in the spread of mutation, cultist and psyker activity and finally daemonic manifestation. Thus Imperial Law is imposed with an iron hand - not only to control wayward subjects; but to prevent predators from another dimension entering material realm. Faced with such threats, it is obivious why edicts of the Imperium are enforced with lethal, uncompromising force.
Those who escape the scrutiny of the Imperium, and there are many skulking in the shadows, often fall pray to their own selfish pride and lust for power. They seek bargain with the denizens of the Warp, to harness the might of the Empyrean in exchange for their obeisance. The sacrifice of human life, promises of serivce and arcane and superstitious ritual are employed by the heretic in his misguided attempts to gain the power of the creatures of Chaos. Ancient, unintelligible languages are chanted in barbaric ceremonies of desecration and treachery to bring forth the foul offerings of the Unnamed Gods. In most cases, such heathen efforts will go unanswered, as only the true student of malevolent arts can really understand the circumstances that allow such creatures access to the material realm. In this way the cultist brings malignant entities forht from the Warp, and it is rare indeed that this does not cost him his soul. Such is the power and lure Chaos, when its influence and servants are unearthed, the Inquisition must execute everyone even remotely in the vicinity lest its taint be spread further. Altought, no matter how many they will slain, Chaos cannot be denied!