Saros howled in annoyance and raised his other hand, summoning a fistful of empyric power. Other members of the Rehati broke ranks and crossed the dais, the song devolving into a discordant jumble.

‘Wait.’ Magnus’ voice echoed through the spheres, causing everyone to halt and fall silent. He lowered his blade and stared at Zadkiel.

Zadkiel realised his mistake. The cyclops had not shrunk to human size. The ever-changing lights of the throne room had confused him. Magnus was a colossus. As he leant forwards to study Zadkiel, he felt like an insect being examined under a lens.

‘The Vulture.’ Magnus’ voice reverberated in the skulls of everyone present. Some of the lesser sorcerers stumbled and clutched the faceplates of their helmets.

‘Your majesty,’ said Zadkiel, freeing himself from Saros and ­bowing low, before scurrying across the dais towards the throne, earning bitter glances from the Rehati. As he approached the daemon primarch, the scale of the being grew more bewildering. ‘I bring news,’ he said, willing the serpents beneath his robes back into a human shape, ‘from the far side of the Great Rift.’

Magnus looked down at him, flames rippling across his enormous, blood-drop eye.

‘You came to tell me of the warp?’ Magnus’ tone was neutral, but Zadkiel knew he was as likely to extinguish him as listen to his reply.

‘Not of the warp, your majesty,’ he said, being deliberately elliptical, hoping to pique his regent’s interest.

The throne room was still, the ranks of Rubricae and Rehati watching in silence. Magnus nodded for Zadkiel to continue.

‘I speak of the Dark Imperium, your majesty. The regions called Imperium Nihilus by the cults of the False Emperor. I speak of the Baal System.’

‘Baal? That arid rock? Is that where you have been hiding yourself while my Great Work nears its completion?’ Magnus waved his blade and the walls of the throne room fell away, revealing the tormented landscape miles below them. Much of Prospero was still charred, a vitrified wasteland, as it had been for ten thousand years, but it was alive with industry. Every withered peak and scarred gulf was crowded with construction sites – barracks and weapons batteries, armouries and manufactoria, as well as huge temples to house the cyclops’ libraries. Magnus was rebuilding the Thousand Sons’ home, long ages after it was destroyed by the Wolves of Russ. But he was not rebuilding it as it was before the fall. There were no gilded spires or crystal pyramids. Prospero would be an anvil, designed to hammer out the tools of war.

As Magnus admired his work, Zadkiel sensed that he was no longer addressing his audience but himself. ‘Ascension is upon us. The Terran corpse has forgotten his great vision but I have not. I will bring the light of knowledge to his children. I will raise them from shameful ignorance. I will elevate them.’ He looked down to the nadir of one of the spheres. ‘I will enlighten them.’