‘The sound,’ Prayto said. ‘They’re making it.’ He pushed himself back from the railing, wiping blood from his face. He worked through the pain with grim determination. His psychic hood ­crackled as if he were fending off an attack. ‘There are lines,’ he said. He was speaking with difficulty. ‘Psychic lines. Between the constructs. And between them and the worlds.’ He winced. More blood appeared on his brow. ‘I can see it. It’s a web…’ His voice trailed off. There was a flare from his hood, and then he was steadier again. ‘It’s holding us here.’

From below, one of the ship’s tech-priests, Byzanus, looked up. ‘With respect, Librarian Prayto,’ he said, his bionic larynx hitching and popping with static, ‘this seems unlikely. We cannot detect any source of energy from the constructs. They are inert.’

‘Their being is enough,’ said Prayto. ‘Their shapes, their positions… The web is created by their conjunctions.’

‘So we have no enemy to combat,’ said Guilliman. ‘What is our status?’ he asked Turetia Altuzer.

‘Almost immobilised,’ said the shipmaster. ‘The warp drive is inert. We have some power in the engines, but not much. We can manoeuvre to a limited degree, but if we get much closer to any of those objects, I’m not sure we’ll be able to resist their gravitation.’

The back of Guilliman’s skull throbbed with pain. If the mass, shape and position of the constructs was creating the sound, then he had to disrupt those conditions. But the constructs were too large to destroy.

‘My lord,’ said Terrens, ‘vox activity coming from Episimos Three.’

‘Human?’

‘Yes.’ Terrens stabbed at the screen before her. ‘It’s broken up badly. They appear to be hailing the fleets.’

‘Take us closer,’ Guilliman ordered. He looked at the fleet positions. The Dark Angels were nearest to Episimos III. ‘Contact the First Legion,’ he told Terrens. ‘I will speak to my brother.’

The vox traffic between the ships was rough. The Lion’s voice scratched in Guilliman’s ear, but he could understand the other primarch well enough. The Dark Angels had picked up the same transmission. At their location, closer to the source, it was clearer.

‘The Imperial forces planetside are under siege,’ the Lion said.

‘I’m impressed they’ve held out this long,’ said Guilliman.

‘I believe their time is growing short. They’re asking for liberation.’

Episimos III was a blackened skull. Its two great hives still burned, embers glowing in eye sockets. Further from the sun, Episimos IV had been the cooler, more temperate heart of the system. Now its surface was a writhing mass of grey flesh. Thin lips pulled back over a continent-wide smile. Teeth showed, then vanished, and another parted, running across the fading scar of the first maw. The world had become hunger. Episimos III, though, still fought. It still screamed.