Another officer, a second lieutenant, spoke up. His jacket front was unbuttoned and an ugly dark sweat stain created a dagger-shaped patch down his shirt.

‘Even if we did, what hope is there while those things haunt the darkness?’

A patched-up corporal, his left eye bandaged, blotched crimson under the medical gauze, stepped forward.

‘I am not leading my platoon out there to be butchered again. The secessionists consort with daemons. We have no defence against it.’

Fear, Tsu’gan sneered. Yes, humans were too weak for some truths.

The second lieutenant turned, scowling, to regard the Salamanders who dwelt in the shadows at the back of the room.

‘And what of the Emperor’s Angels? Were you not sent to deliver us and help end the siege? Are these foes, the spectres in the darkness, not allied to our faceless enemies at Aphium? We cannot break the city, if you cannot rid us of the daemons in our midst.’

Hot anger flared in Tsu’gan’s eyes, and the officer balked. The Salamander snarled with it, clenching a fist at the human’s impudence.

Pyriel’s warning glance made his brother stand down.

‘They are not daemons,’ Pyriel asserted, ‘but warp echoes. A resonance of the past that clings to our present.’

‘Daemons, echoes, what difference does it make?’ asked Mannheim. ‘We are being slaughtered all the same, and with no way to retaliate. Even if we could banish these… echoes,’ he corrected, ‘we cannot take on them and the void shield. It’s simple numbers, my lord. We are fighting a war of attrition which our depleted force cannot win.’

Tsu’gan stepped forward, unable to abstain from comment any longer.

‘You are servants of the Emperor!’ he reminded Mannheim fiercely. ‘And you will do your part, hopeless or not, for the glory of Him on Earth.’

A few of the officers made the sign of the aquila, but Mannheim was not to be cowed.

‘I’ll step onto the sacrificial altar of war if that is what it takes, but I won’t do it blindly. Would you lead your men to certain death, knowing it would achieve nothing?’

Tsu’gan scowled. Grunting an unintelligible diatribe, he turned on his heel and stalked from the strategium.

Pyriel raised his eyebrows.

‘Forgive my brother,’ he said to the council. ‘Tsu’gan burns with a Nocturnean’s fire. He becomes agitated if he cannot slay anything.’

‘And that is the problem, isn’t it?’ returned Captain Mannheim. ‘The reason why your brother-sergeant was so frustrated. Save for you, Librarian, your Astartes have no weapons against these echoes. For all their strength of arms, their skill and courage, they are powerless against them.’

The statement lingered, like a blade dangling precariously over the thread of all their hopes.

‘Yes,’ Pyriel admitted in little more than a whisper.

Silent disbelief filled the room for a time as the officers fought to comprehend the direness of their plight on Vaporis.

‘There are no sanctioned psykers in the Phalanx,’ said the second lieutenant at last. ‘Can one individual, even an Astartes, turn the tide of this war?’