Fulgrim stepped in, not letting his brother widen the gap, and smashed his fist repeatedly into Ferrus's face, hearing bone splinter beneath his assault. Ferrus reeled from the punches, blood drenching the lower half of his face. Fulgrim's senses shrieked with pleasure at the sight of his brother's pain, and his every sense was stimulated by what he was doing.

As Ferrus stumbled, blinded and incoherent, Fulgrim closed and swung his sword for Ferrus's neck. The sword arced towards Ferrus, but instead of raising his weapon to block the blow, Ferrus dropped the hammer and turned into the blow, catching the descending blade in his molten silver hands.

Fulgrim cried out as the pain of the impact jarred his arms. He tried to pull his weapon free, but Ferrus had it locked tight in his hands. The blade was utterly immobile, the chrome-steel of his brother's hands swirling as though changing from solid matter to liquid metal. Fulgrim blinked as the metal of his sword seemed to liquefy and the fire of its blade rippled up Ferrus's hands.

Ferrus opened his eyes, and the fire of the sword was alive in the silver coins of his eyes.

'I forged this blade,' hissed Ferrus, 'and I can break it too.'

No sooner had the words left his mouth than Fireblade exploded in a bright flare of molten metal. Both primarchs were hurled from their feet by the force of the blast, their armour and flesh burned by white hot gobbets of molten metal.

Fulgrim rolled and blinked stars from his eyes, stunned by the force of the explosion. He still held the ruined Fireblade, though all that was left of the sword above the hilt was a smoking nub of hissing metal. The sight of the rained blade penetrated the red mist of sensation that drove him and the symbolism of the weapon's destruction was not lost on him.

Ferrus was dead to him and would rather die than join the new galactic order of the Warmaster. He had hoped it would not come to this, but he knew that there was no other way this drama could end.

Ferrus lay insensible, his hands glowing with the wrath of the Fireblade's unmaking. His brother moaned in pain at the destruction he had wrought, and Fulgrim pushed himself to his feet as his brother groaned at the horror of what had transpired within his sanctum.

Fulgrim leaned down and took up his brother's warhammer, a weapon he had poured his heart and soul into, a weapon that had been forged for his own hand in a time that seemed as though it belonged to another age.

The weapon felt good, and he hefted it easily over one shoulder as he stood triumphantly over his brother's recumbent body. Ferrus propped himself up on his elbows and looked up through blood gummed eyes. 'You had best kill me, for I'll see you dead if you do not.'

Fulgrim nodded and raised Forgebreaker over his head, ready to deliver the deathblow.

The mighty warhammer trembled in his grip, though Fulgrim knew that it was not its weight that made it do so, but the realisation of what he was about to do. The darkness of his eyes met with the blazing silver of his brother's, and he felt his resolve waver in the face of the murder he was about to commit.

He lowered the hammer and said, 'You are my brother, Ferrus, I would have walked unto death with you. Why could you not have done the same for me?'

'You are not my brother,' spat Ferrus through the blood of his ruined face.

Fulgrim swallowed hard as he sought to summon the strength to do what he knew must be done. He heard a dim voice, a faraway whisper that screamed at him to crush the life from Ferrus Manus, but its entreaties were drowned by the memories of the great friendship he had once shared with his brother, for what could compete with such a bond?

'I will always be your brother,' said Fulgrim, and swung the hammer in an upward arc that connected thunderously with Ferrus's jaw. Ferrus's head snapped back and he collapsed to the floor of the Iron Forge, rendered unconscious by a blow that would have sent a mortal man's head spinning through the air for hundreds of metres.

The voice in his head screamed distantly for him to finish the killing, but Fulgrim ignored it and turned away from his brother. He kept hold of the hammer and made his way to the gates that led back into the Anvilarium.

Behind him, Ferrus Manus lay broken, but alive.

The great gates to the Iron Forge swung open and Julius saw Fulgrim emerge bearing the mighty warhammer, Forgebreaker. Gabriel Santar also saw the weapon Fulgrim bore, but was not quick enough to realise its import until Julius turned and shouted, 'Phoenician!'

Instantaneously, the warriors of the Phoenix Guard swung the crackling blades of their golden halberds and beheaded the Morlocks they stood next to with chillingly perfect symmetry. Ten heads clattered to the floor, and Julius smiled as Gabriel Santar and the astropath spun in horrified confusion. The Phoenix Guard closed the noose on the centre of the Anvilarium with measured strides, their bloodied blades extended before them like those of executioners.

'In the name of the Avernii, what are you doing?' cried Santar as the gates of the Iron Forge closed behind Fulgrim with a hollow boom. Julius could see that the First Captain of the Iron Hands was itching to draw his weapon, but did not do so in the certain knowledge that his death would follow as soon as he reached for it.

'Where is Ferrus Manus?' demanded Santar, but Fulgrim silenced him with a shake of his head and a sly smile of pity.

'He is alive, Gabriel,' said Fulgrim, and Julius hid his surprise at this news. 'He would not listen to reason and now you will all suffer. Julius…'

Julius smiled and turned to Gabriel Santar, lightning sheathed claws sliding from the gauntlets of his Terminator armour. Even as Santar saw what must inevitably happen next, it was too late as Julius hammered the crackling blades into his chest and tore them downwards. The energised claws tore through Santar's armour, ripping through his chest cavity and exiting in a gory spray of blood at his pelvis.

The First Captain of the Iron Hands collapsed, his lifeblood flooding from his ruined body, and Julius savoured the delicious aroma of electrically burnt flesh.

Fulgrim nodded appreciatively and opened a channel to the Pride of the Emperor.

'Marius,' he said, 'we will be making our way to the Firebird, and could use something to keep the 52nd Expedition's ships busy. You may open fire.'

Dark currents and swirling colours, unknowable beyond the gates of the empyrean, flowed around the Pride of the Emperor and her small complement of escorts as they forged a passage through the warp. Fulgrim's flagship bore fresh scars of war, but for all that her hull was imperfect, her magnificence was undimmed. The guns of the Iron Hands warships had left their marks upon her once pristine hull, but the shots had been fired in spite and futile defiance, for the broadsides fired by Fulgrim's warships had caught the Iron Hands completely by surprise.

The battle had been short and one-sided, and though the vessels accompanying the Pride of the Emperor were few in number they had inflicted crippling punishment on those of their former allies, and disrupted their ability to respond in any meaningful way.

Much to Marius Vairosean's disappointment, Fulgrim had called a halt to the attack before the destruction of the Fist of Iron was complete. Leaving the crippled X Legion's fleet becalmed, the ships of the Emperor's Children had disengaged and made the translation into the immaterium to rendezvous with the forces of the Warmaster once more.