Realm of Chaos: Slaves to Darkness (1988), p10 — The Spread of Chaos

In the incalculably distant past, the World was visited by the starfaring race known as the Old Slann. Their degree of scientific advancement caused some of the species they met to worship them as gods, while others reviled them as demons. The Old Slann performed many scientific experiments on the World, and although the knowledge of their presence is lost in the present day, many of the races which inhabit the World found their origin in these experiments.

The Old Slann travelled by means of interdimensional gateways, spanning the distances between the stars by travelling through 'warpspace', a parallel dimension which connects all points in the material universe. One of their first tasks upon arriving on the World was to set up a pair of gateways, one at each pole of the planet, to allow them to come and go as they pleased.

Warpspace, however, was not an empty void, but was composed of a form of power wholly alien to the material universe. It was inhabited by entities who were equally alien. As their great ships travelled through warpspace the Old Slann protected themselves with powerful enchantments, but eventually something went dreadfully wrong.

Precisely what happened can now only be guessed. Perhaps the protective enchantments broke down, or the beings that lives in warpspace found some way to overcome them. Or perhaps the gateways broke down under the strain of the magical forces that cycled continually through them. Whatever the cause, the gateways collapsed. Both poles were destroyed, and permanent dimensional tunnels were created between the World and the void of warpspace.

Among the matter sucked through into the World is warpstone, a substance formed of the condensed and solidified essence of Chaos. Warpstone dust rained down upon the World at the time of the catastrophe, twisting many races into strange and horrible shapes and leading to the creation of many new species. The fallout of warpstone dust was also the catalyst that stimulated the development of the Human race, giving it the versatility and lust for change that led to the present Human dominance over many parts of the World. Although few Humans are aware of this, and fewer still would ever admit it, Chaos has left a lasting mark on the Human race, and it it among Humans that Chaos finds its richest source of willing servants.

Many beings from the void chose to send a part of their substance to the World. Some were comparatively small and weak, while others were possessed of almost incalculable power. Thus were born the gods of Law and the gods of Chaos and their daemonic minions. The natural laws of the material universe affected their alien substance in many strange ways, giving them forms and powers which they had not possessed in their home dimension, and they found that they were able to hold sway over the inhabitants of the World, and to use them for the furtherance of their own unfathomable ambitions. There was a constant struggle between the followers of Law and those of Chaos. The gods of Law were few and comparatively weak, but their unity made up for their lack of numbers.

Seven thousand years later, the battle between Law and Chaos still rages across the face of the World, with most of its mortal inhabitants caught helplessly in the middle. The dimensional openings at the poles change constantly, shrinking with the ascension of Law, and growing as Chaos gains the upper hand. All the while, a constant stream of raw Chaos floods through from the void.

For millennia, the tide of Chaos has ebbed and flowed across the face of the World. The worst incident in recent history was the great Incursion of Chaos 200 years ago, when Norsca was completely overrun and the Chaos hordes ravaged the northern parts of the Old World.

This tide is, however, only a single aspect of Chaos. It also acts in subtler ways. Human agents worm their way into positions of authority in many places, and work to further the ends of their unspeakable masters... Chaos is a quick and easy road to power for those with the daring to take it; a daring that is always foolhardy, rash and short-sighted. Chaos has many perils, and a terrible price: it ensnares and seduces, flatters and enriches, mutates and corrupts and, ultimately, destroys. Those who follow Chaos willingly do so at the cost of their sanity, their humanity and their souls.

And in warpspace, the primal void of Chaos, the beings of Chaos will wait and spread their taint across the Imperium and the universe. Warp creatures hover around the vulnerable psykers of humanity, seeking a path into existence through an unprotected mind. Every psychic is a potential gateway from the void of the Warp, and unwitting agent of Chaos to be filled with a terrible power. Only the vigilance of the Emperor's Inquisition protects Humanity from the threat within itself.

And even within the Imperium there are the foolish and weak-minded who turn to the darkness. By embracing the power and horror of warpspace, all that they desire will come to pass...