Perhaps he had been wrong to think a daemon army guarded this path. At least the conduits were as numerous as the first tunnel. Sooner or later, there would be another junction.

The terrible song hesitated again, and then again. Two other companies of Blood Angels had destroyed their first targets. Both times, Sanguinius heard and felt the deep tremor shake the manufactorum. ‘We are damaging this terrible place,’ he voxed the Legion. ‘It knows us. Soon it will fear us, because it will know we have come to kill it.’ But how many spears will it take? he wondered. For all that the Blood Angels had advanced quickly, they had barely broken the skin of the huge forge. There could be hundreds of miles between Sanguinius’ current position and the core. If there was a core.

The slope became steeper. The floor writhed. Sanguinius listened to the song more carefully, hoping to find that it was waning, a hint that the damage was starting to matter.

He found something else instead. The whisper was emerging again, more distinctly than before, as if the wounded animal were desperate to cry out. The words would not be stopped. There were syllables now. They were so slow, long seconds passing between each consonant and vowel, that their refrain was hard to distinguish.

At the next intersection, Sanguinius paused. He listened for the whisper now. It seemed more localised than the rest of the song. The full symphony did not change in volume depending on the route taken. It was the voice of the entire manufactorum, and its voice was everywhere. The whisper was getting louder. And it was getting faster. It slipped out between the pause in the manufactorum’s intakes of breath with such sudden clarity that Sanguinius wondered how he could not have known it for what it was from the start.

It was his name.

‘Lord primarch?’ Azkaellon asked as, with a wounded snarl, Sanguinius plunged down the left tunnel in pursuit of the voice.

‘Can you hear it?’ asked Sanguinius.

‘The song, my lord?’

‘No, the whisper.’

Azkaellon said nothing for a moment, listening. ‘I hear no whisper.’

‘Raldoron?’ Sanguinius called. ‘Can you still hear the voices?’

‘No, my lord.’

‘Then it is for my ears alone. The enemy is preparing a more insidious attack.’ The thought came that the daemonic power that held the manufactorum might not be on the defensive at all. Sanguinius dismissed the pessimism. The wounds were real. The music had fractured.

Sanguinius followed the hissing syllables of his name. It summoned him, and he answered. I do not die here, he thought. My end will come, but today, I am the one who brings the end.

Daemons roared in the distance, always in the distance, always around the next bend, but never arriving.