The adulation soared to new heights as the Eye of Horus seared itself into the sands of Isstvan V, the Warmaster's forces roaring themselves hoarse in his praise. Super-heavy tanks fired in salute of Horus, and the towering immensity of the Dies Irae inclined its massive head in a gesture of respect.
The ashes of the dead fell like confetti over the Warmaster's mighty army. Lucius felt a huge surge of purpose fill his heart and made a vow to never once rest in the service of the power Horus represented. Not even death would contain his might. He gripped the hilt of his sword tightly as loudspeakers placed around the desert erupted with sound, the booming, stentorian voice of the Warmaster sweeping over the Astartes.
'My brave warriors!' began Horus. 'We have achieved much, but there is still more for us to do. With courage, vision and power we have defeated those who sought to prevent us from realising my great dream, but our victory here will count for little if we do not press onwards.'
Horus punched his clawed gauntlet into the air and shouted, 'The road to Terra is open. The time has come for us to take the war to the Emperor in his most impregnable fastness! We will make immediate preparation for the invasion of Terra and an assault on the Imperial Palace. Make no mistake, and it will be ours, my brothers! This will be no easy task, for the Emperor and his deluded followers will fight hard to prevent us from interfering with his plans for godhood. Doubtless much blood has yet to be spilled, theirs and our own, but the prize is the galaxy itself Horus paused as he let the weight of the stakes sink in before bellowing across the fields of Isstvan V, 'Are you with me?'
Lucius joined the cheering as it reached into the fire-lit skies, and cries of ''Hail Horus! Hail Horus!'' resounded long into the darkness.
Within the ruined keep of Isstvan V, shadows cast by the funeral pyres were thrown out on the smooth, basalt flagstones. Dust motes shaken from the ceiling and walls by the rumble of thrusters hung heavily in the air as the Warmaster's army took its leave of the fifth planet. Horus watched as yet another squadron of Stormbirds lifted off in clouds of dust lit by blue fire, satisfied that all was proceeding as he desired.
His brother primarchs were mustering their forces for the invasion of Imperial space, and he was certain that each and every one understood the need for unquestioning obedience to his orders. As Warmaster, the armies of the Imperium had been his to control, from the mightiest fleet of battleships to the lowliest Army soldier, but to see such martial power gathered in one place was truly inspiring.
Not since Ullanor had he witnessed such a gathering of heroes, and his mood soured as he thought once again of the devastated greenskin world and the last time he had seen his father. Time had moved on and revealed much that had been hidden, but still the unease that events were moving too fast for him to control gnawed at the furthest corners of his mind.
He turned from the window and poured himself a cup of wine from a brass pitcher he lifted from a nearby table. He drained the wine in a single swallow and poured another as a rapid knocking sounded at the chamber's entrance.
Horus looked up, his mood souring further as he saw Fulgrim standing in the doorway, a gilt inlaid box held before him.
Once they had shared a brotherhood as close as any, but in the years since they had fought together, something had changed within Fulgrim. His brother had been a warrior of perfection, but now he simply revelled in the sensations of battle and the adrenaline high of ferocious combat instead of the precise application of force.
His brother wore his battle armour, the plates gleaming and new once again, as though he had never set foot upon a battlefield. He wore a long cape of fiery golden scales at his shoulders, and a mail shirt of glittering silver hung beneath his breastplate. What had once been a magnificent, all-enclosing suit of armour now resembled a theatrical costume. 'Warmaster,' said Fulgrim.
Horus detected a subtle difference in his brother's tone, something so slight that it would have escaped anyone else's notice but his. He lifted his cup and drank a mouthful of wine, beckoning Fulgrim into his chambers.
'You requested a private audience with me, Fulgrim,' he said. 'What is so important that you could not tell me in front of our brothers?'
His brother smiled and bowed before opening the box he carried. 'My esteemed lord and master of Isstvan, I have brought you a trophy.'
Fulgrim reached into the box and withdrew a grisly prize lifted from the field of battle. Horus felt a momentary shiver of horror as he saw the severed head of Ferrus Manus.
The flesh was grey and dead, his erstwhile brother's silver eyes plucked from his head, and the sockets raw and bloody. His jaw hung open and a splintered nub of bone projected from where his skull had been caved in on one side.
Ferrus had become an enemy, but to see his flesh violated so brutally was repugnant to Horus, though he was careful to keep his feelings veiled.
With a casual flick of the wrist, Fulgrim tossed the bloodied object at Horus's feet. Ferrus Manus's head rolled across the black floor and came to rest with the ravaged eye sockets staring up at Horus in blind accusation.
Horus looked up from the head and turned his gaze on Fulgrim, seeing again the insouciance that had infuriated him so when his brother had returned in failure from his attempt to win over the Primarch of the Iron Hands.
As distasteful as it was, he knew he would have to offer congratulations. 'Well done, Fulgrim. You have slain one of our greatest foes as you said you would, but I fail to see why you make this presentation in so private an audience. Surely you would wish our brothers to revel in your triumph?'
Fulgrim laughed, but there was a timbre to his brother's amusement that sent a chill down Horus's spine as he recalled where he had heard such ancient malice before… in the voice of Sarr'Kell, the entity Erebus had summoned in the heart of the Vengeful Spirit.
'Fulgrim?' asked the Warmaster. 'Explain yourself.'
The Primarch of the Emperor's Children shook his head and wagged his finger at Horus. 'With the greatest respect, mighty Horus, you do not address Fulgrim any more.'
Horus looked into his brother's dark eyes, seeing beyond the arrogance and superiority to what lay within. Darkness filled his brother's core, an ancient darkness that had torn itself from the womb of a dying race with a bloody birth scream.
Its existence was as old as the heavens and as fresh as the dawn. Its life was immortal and its capacity for malice infinite.
'You are not Fulgrim,' he breathed, suddenly wary of this intruder in his midst.
'No,' agreed the thing with his brother's face.
'Then who are you?' demanded Horus. 'A spy? An assassin? If you are here to kill me then I warn you I am no weakling like Fulgrim. I will break you before you can lay a hand upon me!'
Fulgrim shrugged and tossed the box he carried onto the floor with a clatter. It landed next to Ferrus's severed head. Horus let the energised claws of his gauntlets slide out in warning.
'Perhaps you can defeat me,' said Fulgrim, crossing the room to pour himself a cup of wine, 'but I have no wish to test either of us in such a fruitless and wasteful trial of combat. On the contrary, I am here to pledge myself to your cause.'
Horus glanced towards Fulgrim's waist, and relaxed as he saw that this thing masquerading as his brother had come before him unarmed. Whatever its purpose in unveiling itself, it had not come with violence on its mind.
'You still have not answered my question,' said Horus. 'Who or what are you?'
Fulgrim smiled and licked his lips with a long sweep of his tongue. 'Who am I? I should have thought that would be obvious to one who has had dealings with other creatures of my ilk.'