He caught a sudden, startled furrowing of Erebus's brow and experienced a moment's panic as he wondered if the Word Bearer had heard the voice too.

Fulgrim pushed aside such concerns and nodded at Horus's words. 'I understand perfectly,' he said.

'I see,' said Horus, 'and the Council's concern is simply with Angron's bloodlust?'

'Not entirely,' he replied. 'As I said, the Wolf of Fenris has been despatched to Prospero in order to bring Magnus back to Terra, though for what purpose I do not know.'

'He has been practising sorcery,' said Erebus. Fulgrim felt a spike of anger enter his heart at the warrior's temerity in addressing a primarch without a direct question being asked of him.

'Who are you to speak without leave in the presence of your betters?' he demanded, turning to Horus and waving a dismissive hand at the Word Bearer. 'Who is this warrior anyway and tell me why he joins our private discussions?'

'Erebus is… an advisor to me,' said Horus. 'A valued counsellor and aide.'

'Your Mournival is not enough for you?' asked Fulgrim.

'Times have changed, my brother and I have set plans in motion for which the counsel of the Mournival is not appropriate, matters to which they cannot yet be made privy. Well, not all of them at any rate,' he added with a pained smile.

'What matters?' asked Fulgrim, but Horus shook his head.

'In time, my brother, in time,' promised Horus, rising from behind his desk and circling it to stand before the mural of the Emperor. 'Tell me more of Magnus and his transgressions.'

Fulgrim shrugged. 'You now know as much as I, Horus. All I was given to understand I have now told you.'

'Nothing of substance as to how Magnus is to travel to Terra? As a penitent or a supplicant?'

'I do not know,' admitted Fulgrim. 'Though to send one who dislikes Magnus as much as the Wolf to fetch him home suggests that he does not travel to Terra to be honoured.'

'It does not,' agreed Horus, and Fulgrim could see a glimmer of relief ghost across his brother's face. Had Magnus, like Eldrad Ulthran, seen a glimpse of the future and attempted to give warning of an imminent betrayal? If so, the Warmaster would need to deal with him before his return to Terra.

With the matter of the Lord of Prospero dispensed with to his apparent satisfaction, the Warmaster nodded in the direction of the mural and said, 'You said you remembered this being made.'

Fulgrim nodded, and the Warmaster continued. 'So do I, vividly. You and I, we had just felled the last of the Omakkad Princes aboard their observatory world, and the Emperor decided that such a victory should be remembered.'

'While the Emperor smote the last of their princes, you slew their king and took his head for the Museum of Conquest,' said Fulgrim.

'As you say,' nodded Horus, tapping a finger against the painting. 'I slew their king, and yet it is the Emperor who holds the constellations of the galaxy in his grip. Where are the murals that show the honours you and I won that day, my friend?'

'Jealousy?' chuckled Fulgrim. 'I knew you thought highly of yourself, but I never expected to see such vanity.'

Horus shook his head. 'No, my brother, it is not vanity to wish your deeds and achievements recognised. Who among us has a greater tally of victory than I? Who among us was chosen to act as Warmaster? Only I was judged worthy, and yet the only honours I possess are those I fashion for myself.'

'In time, when the Crusade is over, you will be lauded for your actions,' said Fulgrim.

'Time?' snapped Horus. 'Time is the one thing we do not have. In essence, we may be aware that the galaxy revolves in the heavens, but we do not perceive it, and the ground upon which we walk seems not to move. Mortal men can live out their lives undisturbed by such lofty concepts, but they will never achieve greatness by inaction and ignorance. So it is with time, my brother. Unless we stop and take its measure, the opportunity for perfect glory will slip away from us before we even realise that it was there.'

The words of the eldar seer echoed in his head as though shouted in his ear.

He will lead his armies against your Emperor.

Horus locked his gaze with him, and Fulgrim felt the fires of his brother's purpose surge like an electric current in the room, feeding the flames of his own obsessive need for perfection. As horrified as he was by the things he was hearing, he could not deny a powerful force of attraction swelling within him at the thought of joining his brother.

He saw the rampant ambition and yearning for power that drove Horus, and understood that his brother desired to hold the stars in his grip, as the Emperor did upon the mural.

Everything you have been told is true.

Fulgrim leaned back in his chair and drained the last of his wine.

'Tell me of this perfect glory,' he said.

Horus and Erebus spoke for three days, telling Fulgrim of what had befallen the 63rd Expedition on Davin, of the treachery of Eugan Temba, the assault on the crashed Glory of Terra, and the necrotic possession that had taken his flesh. Horus spoke of a weapon known as the anathame, which was brought to his staterooms by Fulgrim's Apothecary after he had handed Fabius his seal to have it removed from the Vengeful Spirit's medicae deck.

Fulgrim saw that the sword was a crude thing, its blade like stone-worked obsidian, a dull grey filled with a glittering sheen like diamond flint. Its hilt was made of gold and was of superior workmanship to the blade, though still primitive in comparison to Fireblade, or even the silver sword of the Laer.

Horus then told him the truth of his injury, how he had, indeed, almost died but for the diligence and devotion of his Legion's quiet order. Of his time in the Delphos, the massive temple structure on Davin, he said little, save that his eyes had been opened to great truths and the monstrous deception that had been perpetrated upon them.

All through this retelling, Fulgrim had felt a creeping horror steal across him, a formless dread of the words that were undermining the very bedrock of his beliefs. He had heard the warning of the eldar seer, but until this moment, he had not believed that such a thing could be true. He wanted to deny the Warmaster's words, but each time he tried to speak a powerful force within him urged him to keep his counsel, to listen to his brother's words.

'The Emperor has lied to us, Fulgrim,' said Horus, and Fulgrim felt a knot of hurt anger uncoil in his gut at such an utterance. 'He means to abandon us to the wilderness of the galaxy while he ascends to godhood.'

Fulgrim felt as though his muscles were locked in a steel vice, for surely he should have flown at Horus to strike him down for such a treacherous utterance. Instead, he sat stunned as he felt his limbs tremble, and his entire world collapsed. How could Horus, most worthy of primarchs be saying such things?

No matter that he had heard them before from different mouths, the substance of their reality had been meaningless until now. To see Horus's lips form words of rebellion kept him rooted to his chair in horrified disbelief. Horus was his most trusted friend, and long ago they had sworn in blood never to speak an untruth to one another. With such an oath between them, Fulgrim had to believe that either his father or his brother had lied to him.

You have no choice! Join with Horus or all you have striven for will have been in vain.

'No,' he managed to whisper, tears welling in his eyes. The anticipation of this moment had fired his senses, but the reality of it was proving to be very different indeed.

'Yes,' said Horus, his expression pained, but determined. 'We believed the Emperor to be the ultimate embodiment of perfection, Fulgrim, but we were wrong. He is not perfect, he is just a man, and we strove to emulate his lie.'