Vulkan bore a wondrously crafted weapon with a top-loading magazine and perforated barrel formed in the shape of a snarling dragon. Balhaan had heard of the gun, its brass and silver body having been crafted by Ferrus Manus many years ago for his brother primarch. Balhaan had watched as his primarch had presented it once again to Vulkan, and felt great pride swell within him as the dark-skinned warrior had graciously accepted the legendary weapon and sworn to bear it in the coming battle.

To stand in close proximity to such mighty warriors was an honour Balhaan knew would never be equalled. He resolved to remember every detail of this moment and record it as best he could, so that future captains of the Ferrum would know the honour accorded their vessel in times past.

Balhaan had pushed the crew of his ship to its very limit to reach the Isstvan system with such speed, and now that they had arrived, it was to find that they had come alongside the fleets of the Raven Guard and Salamanders. Discreet reconnaissance had identified enemy positions, and the primarchs had mapped out landing zones as well as optimal attack patterns, but without the other Legions tasked with destroying Horus's rebellion, nothing could be done.

To have reached their destination and be unable to enact the Emperor's will was a supreme frustration, but even Ferrus Manus's rage had recognised that they could not overwhelm the Warmaster's forces without support.

Ten companies of the Morlocks were berthed throughout the Ferrum, the deadliest and most experienced warriors of the Legion, and Balhaan knew that whatever force was arrayed against the Terminators, it could not survive their wrath. The Iron Hands would undertake the initial assaults with the veterans of their Legion, and Balhaan felt that it was appropriate that the Legion's best warriors should be first into battle. Led by Gabriel Santar, the Morlocks hungered to confront the Emperor's Children and make them pay for the dishonourable murders done to their number in the Anvilarium of the Fist of Iron.

The rest of the 52nd Expedition was following behind the Ferrum, but when they might arrive in-system was unknown, and every second their assault was delayed gave the Uaitors more time to fortify their positions.

The Legions of Corax and Vulkan were in position to commence their attack runs on Issrvan V, but Astropath Cistor had received no word from Ferrus Manus's brother primarchs of the Word Bearers, Night Lords, Iron Warriors or Alpha Legion.

'Are all units ready and in position?' asked Ferrus Manus without turning from the viewing screen.

Balhaan nodded and said, 'They are, my lord.'

'Still no word from the rest of the Legions?'

'None, my lord,' said Balhaan, checking the link to the choral chambers of the Legion's few surviving astropaths. The same ritual had been repeated every few minutes as Ferrus Manus chafed at the delay in ordering the attack, the waiting interminable for warriors who lusted to strike back at those who tarnished the honour of their brothers with their treachery.

The hatch to the bridge slid open and a pair of the Terminator armoured Morlocks entered, followed by the gaunt figure of Astropath Cistor.

Barely had he stepped within the bridge than Ferrus Manus was at his side, his gleaming hands taking the astropath by the shoulders in a crushing grip—

'What news of the other Legions?' demanded Ferrus, his craggy features and blazing silver eyes centimetres from Cistor's.

'My lord, I have personally received word from your brother primarchs,' said Cistor, squirming in the primarch's grip.

'And? Tell me, are they en route? Can we commence the attack?'

'Ferrus,' said Corax, his voice soft, yet laden with quiet authority, 'you will crush him to death before he tells you. Release him.'

Ferrus let out a shuddering breath and stepped back from the quivering astropath as Vulkan stepped forward and said, 'Tell us what you have heard.'

'The Legions of the Word Bearers, Alpha Legion, Iron Warriors and Night Lords are mere hours behind us, my lord Vulkan,' said Cistor calmly. 'They will break warp close to the fifth planet.'

'Yes!' shouted Ferrus, punching the air and turning to his brother primarchs. 'The honour of drawing first blood in this battle falls to us, my brothers. We go for full planetary assault.'

Ferrus's enthusiasm was infections, and Balhaan felt his blood fire with the knowledge that they were soon to take the wrath of the Emperor's judgement to the traitors. His primarch resumed his pacing of the bridge as he threw out orders to his brothers.

'The Morlocks and I will take the vanguard,' said Ferrus. 'Corax, your Legion is to secure the right flank of the Urgall Depression and then push into the centre. Vulkan, you have the left wing.'

The primarchs nodded at Ferrus's words, and Balhaan could see that even the normally stoic Corax relished the prospect of destroying the enemy below.

'The other Legions will make planetfall as soon as they break warp. They will secure the dropsite and reinforce our assault,' cried Ferrus, his eyes ablaze with magnesium fire.

He shook his brothers' hands and turned to address the crew of the Ferrum. 'The traitors are not expecting us to assault so soon, and we have the advantage of surprise. The Emperor damn us if we waste it!'

The delays enforced upon Ferrus Manus had not been wasted by the Warmaster's forces. Since their arrival at Isstvan V, eight days ago, the warriors of the World Eaters, Death Guard, Sons of Horus and Emperor's Children had deployed throughout the defences constructed along the ridge of the Urgall Depression, making ready for the howling storm of battle that was soon to descend upon them. Behind them, long range, support squads manned the walls of the fortress, and Army artillery pieces waited to shower any attacker with high explosive death.

The Dies Irae stood before the wall, its colossal guns primed and ready to visit destruction on the enemies of the Warmaster, Princeps Turnet personally swearing to atone for the treachery that had engulfed his command during the Battle of Isstvan III.

Nearly thirty thousand Astartes hunkered down on the northern edge of the Urgall, their guns ready and their hearts steeled to the necessity of what must be done.

The skies remained an unbroken canopy of slate grey clouds, and the only sound to break the ghostly howl of the wind was the scrape of metal on metal. A sense of historic solemnity hung over the black desert, as though all gathered knew that these were the last moments of quiet in what was soon to be a bloody battlefield.

The first warning came when a dull, red orange glow built behind the clouds, bathing the Urgall in a fiery light. Then came the sound: a low roar that built from a deep, thrumming bass to a shrieking whine.

Alarms sounded and the clouds split apart as individual streaks of light burned through and fell in a cascading torrent of fire. Thunderous explosions ripped along the edge of the Urgall, and the entire length of the Warmaster's forces was engulfed in a searing, roaring bombardment.

For long minutes, the forces of the Emperor pounded the Urgall from orbit, a firestorm of unimaginable ferocity hammering the surface of Isstvan V with the power of the world's end. Eventually, the horrific bombardment ceased and the drifting echoes of its power faded, along with the acrid smoke of explosions, but the Emperor's Children had performed perfectly in creating a network of defences from which to face their former brothers, and the forces of the Warmaster had been well protected.

From his vantage point in the alien keep, the Warmaster smiled, and he watched the sky darken once again as thousands upon thousands of drop-pods streaked through the atmosphere towards the planet's surface.