A tall church, its facade of stone scorched black and greasy, stood proud amid the ruins, as though whatever calamity had befallen the city had seen fit to spare the mighty edifice the worst of its attention. Tall spires cast long shadows over the city and the great eagle-winged pediment that had once sat proudly above the arched entrance now sagged in defeat, its wings dipped and streaked with green corrosion.

High windows that glorified the Emperor and His many saints were shattered and empty, fragments of coloured glass jutting like teeth in rotted frames. The heavy iron doors that had once protected the main vestibule of the church lay twisted and broken on the cracked flagstones of the esplanade. Shattered statues lay beside the doors, fallen from the roof and left to crumble where they lay.

The wind collected here, as though drawn by some unseen imperative to gambol in the open square before the church. Wisps of mist were dragged along with the wind and fluttering scraps of cloth, paper and leaves spun in miniature whirlwinds as the strength of the wind gathered force.

The gaping blackness of the church's entrance seemed to swallow what little light was left of the day, and though the wind pulled the leaves and debris of the city back and forth with ever-greater vigour, none dared violate the darkness within the abandoned building.

A hollow moaning issued from the church, though nothing lived within it - or indeed in the entire city - and a gust of air, colder than the depths of space, blew into the square.

Beginning as spots of brightness against the black, rippling streamers of light oozed from the arched entrance and flowed like ghostly lines of mercury along the ground in two parallel tracks. Before, the church had seemed relentlessly solid and immovable, now its fabric seemed to ripple and warp as though in the grip of a monstrous heat haze.

The moaning built, rising from a far distant sound to something much closer, a shrieking howl of a thing in agony that fought to hold itself together as though its very sinews were being unravelled with every passing second.

The darkness of the church's interior swelled, billowing outwards like an explosive ink stain. Then it retreated, spilling back over something that had violated time and space to enter this world, a churning, seething remnant of a thing first given form in another age.

It resembled a great juggernaut machine of pistons and iron, its brazen flanks heaving with unnatural energies as it thundered from the church. Steam leaked from every demented, skull-faced rivet as wheels of rusted, dissolving iron ground the mercurial tracks beneath it.

Deep within its fragmenting structure, it might have once resembled an ancient steam-driven locomotive, but unknown forces and warped energies had transformed it into something else entirely.

Whatever power had once fashioned the monstrous, terrifying amalgamation of machine and dark energy now appeared to be working to unmake it. Flaring whoops of light streamed from it, peeling back like the layers of an onion. The very air seemed toxic to its existence, hissing clouds of stinking vaporous light billowing from its every surface.

The terrible machine screamed like a wounded beast, but deep within the aching agonies of its dissolution, there was a keening note of welcome release, as though an eternity of torment had come to an end. Its passage slowed until it came to a halt, like a hunted beast that had reached the end of its endurance and could run no more.

Within the tortured end of the machine, there was the suggestion of voices, a hint of things within it that were not part of its decay. The sounds of the voices grew stronger with each passing second, as though their owners called out from some freshly unlocked, yet still impossibly distant chamber.

As a portion of the juggernaut dissolved, it revealed a dreadful glimpse of the machine's red-lit interior, a stinking meat locker that reeked of unnumbered slaughters and debaucheries, roaring fires and an eon's worth of bloodshed.

Shapes moved within the light, a handful of figures that stumbled like newborns or drunks as they spilled like entrails from the dying machine. Tall, broad and humanoid, they scrambled and crawled from the light as though in pain.

The figures emerged from the armoured leviathan that had brought them to this world, wreathed in coiling wisps of smoke. Their steps were feverish and unsteady, but even unsteady steps were welcome, so long as they carried them away from the dissolving machine.

As the figures put more distance between themselves and the heaving engine, their shapes resolved into clarity, though, had an observer been watching this incredible arrival, he might have wished that they had not.

They were monsters: the Unfleshed.

They were twisted freaks of nature, the bastard by-blows of hideous surgery, failed experiments and dreadful power of unnatural origin. No two were alike, their skinless bodies massive and grotesque, their heads swollen, encephalic nightmares of distended eyes, ripped faces and gnashing fangs.

To see such things would have driven many a man mad with fear, but had anyone had the courage to look beyond the physical deformities and hideous malformations of bone and flesh, they would have seen something else, something that would no doubt have horrified them even more: the glimmer of human understanding and awareness.

Two other figures followed the monstrous creatures, as stumbling and as dazed as the monsters, but without the horrifying aberrations of the flesh that afflicted them. Both had the bulky, gene-built physique of Astartes. One was broader and more powerfully built than the other, although his right arm ended abruptly at the elbow.

One was clad in blue armour; the other in fragments of armour the same colour. The first wore his dirty blond hair tight to his skull, his features wide and open, while the other, dark haired, grey-eyed and wolf-lean, had a face that was stern and patrician.

Both warriors, for it was clear from the wounds and weapons they bore that these were men to whom the crucible of combat was no strange and unknown place, staggered away from the disintegrating machine, collapsing to the ground and heaving great draughts of cold air into their lungs.

With the disembarkation of its passengers, the mighty engine that had carried them squealed with the sound of metal grinding on metal as the burning wheels of iron dragged the strange and terrible machine away from the place.

Confined so long to realms beyond the material universe, its substance was unused to the assault of the elements that made up this existence, and the abrasive banality of reality was undoing its unknowable, warp-spawned structure as surely as a flame devours ice.

Its former passengers watched it gather momentum, moving slowly at first and then with greater speed as its form became ever brighter, as if some infernal power source within was drawing close to critical mass. Its brightness soon became too much to bear, even for those whose eyes were genhanced to withstand such things. With a tortured scream, though whether one of death or release none could tell, the living engine vanished in an explosion of light.

No violence or blast spread from this explosion, but a glittering rain of light fell and saturated the air with the sense of an infinite power having been released into the world.

With the final dissolution or escape of the great, immaterial engine, the gloom and dread of the dead city smothered the world once more, the rain bathing the bedraggled travellers in cold, clammy wetness.

The two Astartes warriors found each other in the rain, embracing like brothers at the simple joy of having returned to a world where the air was not a toxic soup of pollutants, ashen bone matter and the hot, sad smell of burned iron and war.