‘Join with me,’ said Fulgrim seductively. ‘You must be tired of all this strife. We can bring an end to war, and revel together in sweet excess for all eternity. I can show you things, pleasures, you would never have dreamed existed. You think of the warp as a hell, but it can be a heaven also. Together, we can usher in an age of delight for all mankind that will never end.’

‘Never,’ said Guilliman. ‘You have been deceived. I will not follow you into darkness.’ He stepped backwards, his hand going to the hilt of the Gladius Incandor. The primarchs were mighty beings and great in stature, but swollen with the power of Chaos, Fulgrim overtopped Guilliman by almost a metre.

‘It is you who has been deceived, Roboute,’ said Fulgrim.

‘Look at what you have become, and you will see the wages of disloyalty.’

‘You speak to me of loyalty.’ Fulgrim tutted and shook his long warped head. ‘And where do your loyalties lie, lord commander? You were late to the Palace, were you not? Delayed. Always, your love for your own kingdom trumps your so-called loyalty to our father. Like a little Emperor, playing at being daddy in the sand, making tiny empires. You would have saved the Five Hundred Worlds and lost the million of our father. Pathetic.’ A long, forked tongue flitted over his painted lips. ‘How are your Five Hundred Worlds now, brother? How many are left? Four hundred? Three? I hear Angron and Lorgar had a rare time bringing down the bastions of your puny realm and slitting the throats of your people.’

Guilliman’s anger ran hot. ‘I will not bend my knee to your masters. These gods you and the others profess to worship are not gods. They are monsters, nothing more. There can be no rapprochement between us. No reconciliation. You have become the tool of the enemy, and so I must kill you.’

‘You have come to kill me? Really? How amusing, because I have come to kill you!’ said Fulgrim with mocking surprise. He clapped his upper pair of hands. ‘What a coincidence. You do realise, I need no starship to travel the void.’ He gestured at his body, his four hands moving with obscene, suggestive precision. ‘I am no longer a thing of this realm of ash and dust, but a radiant creature of the warp.’ He pulled a moue of sympathy. ‘Oh, I am so sorry, but this was a trap for you, Roboute – the whole thing, from my first raids to your supposed victory at Xolco, and you have fallen into it.’

Since the first indication of Fulgrim turning to fight here, Guilliman had known he had been outplayed, but he would not give his brother the satisfaction of knowing this. He steeled his heart and prepared to fight.

‘I will not be turned.’

‘I never thought you would,’ said Fulgrim sweetly.