Such were the myths of Isstvan as preached by the Warsingers, cautionary tales that warned their people to follow the true path, lest the Lost Children return and finally take their long awaited vengeance.

Whether these myths were allegorical parables or were in fact history was irrelevant, for, in the shape of the Warmaster's Legions, the Lost Children had indeed returned.

The skies of Isstvan V were grey and ashen, dark clouds gathering in rumbling thunderheads to the south of where the first battle for the Imperium would be fought. As places of legend went, it was not particularly impressive, thought fulius Kae-soron. The air tasted of long vanished industry, and the ground underfoot was a dusty black powder, fine and granular like sand, but hard and crunching like glass.

When Julius had first set foot on the black deserts of Isstvan V, a howling wind had been whipping across the black dunes, echoing mournfully through the towers and weathered battlements of an ancient fortress, which stood atop a gently sloping ridge at the northern edge of a vast emptiness. Known as the Urgall Depression, it was the planet's largest desert, a featureless plain of bare rock and scattered scrub that rose gently to low hills upon which was built the fortress. Who had raised it was unknown, though the Mechanicum adepts postulated that it belonged to a civilisation that predated humanity by millions of years.

Its walls were formed of enormous blocks of a hard vitreous stone, each one the size of a Land Raider, and carved with such precision that there was no evidence of any bonding agent between them. Its builders were long dead, but their architectural legacy had endured the passage of aeons, though long stretches of the wall had collapsed over the millions of years. Such ruin rendered it untenable as a fortress, but ideal as a bulwark against which to mount a defence. The wall stretched for nearly twenty kilometres and rose to heights of thirty metres in places, with slopes of gritty sand banked against it and filling the hallways of its mighty, turreted keep.

Fulgrim had set up his command within the remains of the keep and begun the work of ensuring that it would be a bastion worthy of the Warmaster.

Together with Marius, Julius followed the Primarch of the Emperor's Children as he toured the mighty works of fortification being undertaken here. Vast teams of Mechanicum earthmovers were shifting the sand from before the walls of the fortress and using it to form a vast network of earthworks, trenches, bunkers and redoubts that stretched along the ridge before the fortress. Laagers of anti-aircraft batteries were set up in the shadow of the walls, and mighty orbital torpedoes on mobile launch vehicles hid in the warrens of the fortress. If the Emperor's Legions wanted to destroy them, they were going to have to come down to the surface to do so.

The Primarch of the Emperor's Children was arrayed in his plate armour, the gleaming ceramite burnished to a brilliant purple, though Julius's newly enhanced vision detected hundreds of subtle variations of hue within each plate. Legion artificers had added many layers to the armour, its sweeping curves accentuated in new and wondrous ways, the Imperial Eagle removed from his breastplate and replaced with gracefully carved bands of lacquered ceramite.

Silver and gold edged every plate and scenes representing the Legion's new loyalties were carved onto every surface, lending the armour the appearance of something purely ceremonial, though such an impression could not be further from the truth.

'A fine sight is it not, my friends?' asked Fulgrim as he watched a gigantic bulldozer the size of a Titan lander scooping hundreds of tonnes of sand and rubble into a similarly gigantic hopper.

'Majestic,' said Julius without enthusiasm. 'The Warmaster will be pleased, I'm sure.'

'He will indeed,' replied Fulgrim, oblivious to the irony in his tone.

'Do we know yet when Horus will grace us with his presence?' he asked.

Fulgrim turned, finally hearing Julius's ennui. He smiled, sweeping a hand through his unbound white hair, and Julius felt his spirits aroused by the sight of the beautiful primarch. In deference to the Warmaster, Fulgrim had dispensed with the powder and paints on his face and more resembled his old self, a glorious warrior of utmost perfection.

'The Warmaster will join us soon, Julius,' said Fulgrim, 'and so too will the Legions of the Emperor! I know this work seems tedious to you, but it is necessary if we are to achieve the great victory Horus requires.'

Julius shrugged, his senses crying out for stimulation. 'It is humiliating. The Warmaster could have thought of no greater punishment than denying us a place in the battle for Isstvan III and consigning us to become ditch diggers and grubby labourers on this desolate rock.'

'We all have our part to play,' said Marius, ever the sycophant, but Julius could see that he too did not relish this work and smarted at missing the glory of expunging the imperfect from their Legion. The battles on Isstvan III had been glorious, and Eidolon had sent word of the perfection of the Legion's conduct as well as the fact of Solomon Demeter's death.

Unlike when Lycaon had died fighting the Diasporex, Julius hadn't known what to feel upon hearing of his former battle-brother's end. His senses were heightened to the point that only the most shocking things could evoke more than a glimmer of passing interest. He felt no sadness, only a mild regret that a warrior as fine as Solomon had proved to be imperfect, and thus deserving of his fate.

'That we do, Marius,' agreed Fulgrim. 'The work we do is vital, Julius, that is why Horus has entrusted it to us. Only the Emperor's Children bring the perfection required to ensure that this phase of the Warmaster's plan plays out as ordained.'

'This work is fit only for the workers of the Mechanicum and perhaps the dour Iron Warriors of Perturabo's Legion. For it to be foisted upon the Emperor's Children is demeaning,' said Julius, unrepentant in his defiance. 'We are being punished for our failure.'

Though Fulgrim had been devastated at his exclusion from the battles raging on Isstvan III following the disastrous mission to bring over Ferrus Manus, he had nevertheless thrown himself into the preparations for Horus's triumphant arrival like a man possessed.

The Legions of the Emperor were massing to destroy them and soon the battle that might very well determine the fate of the Imperium would be fought on this desolate plain.

'Maybe so,' growled Fulgrim, 'but it will be done.'

With the destruction of the last surviving warriors on Isstvan III, the Legions of Horus made their way to Isstvan V, a flotilla of powerful warships and carriers bearing the martial pride of four Legions, their ranks fully comprised of those whose loyalty was to Horus and Horus alone.

Mass conveyers of Lord Commander Fayle's Army units brought millions of armed men and their tanks and artillery pieces. Bloated Mechanicum transports bore the Legio Mortis to Isstvan V, dark priests of the Machine ministering to the Dies Irae and its sister Titans as they prepared to unleash the unimaginable power of these land battleships once more.

Final victory on Isstvan III had been bought with many lives, but in its wake the Legions were tempered in the crucible of combat to do what must be done to save the Imperium. The process had been long and bloody, but the Warmaster's army was ready and eager to fight its brothers, where the lackeys of the Emperor would find their readiness to strike down their kith and kin untested.

Such mercy would be their undoing, promised Horus.

The atmosphere in La Venice was tense and ripe with potential. Thousands packed its stalls and boxes, the vividness of the art, sculpture and colours overwhelming the senses with their extravagance. Nearly three thousand Astartes warriors had returned to the Pride of the Emperor from the surface of Isstvan V, and some six thousand remembrancers and ship's crew jammed themselves between the warriors wherever a space could be found. The excited hubbub of conversation filled the theatre.