Though my eyes were gummed with blood, my helmet gone, I swore I saw Curze smiling as he looked down on me as at one of his slaves. The bastard. Even now, I believe he found it amusing. All the horror, the dirty shame of treachery and how it stuck to all of our skins. We primarchs, we who were supposed to be the best of all men, turned out to be the very worst.

Konrad had always enjoyed irony like that. It brought us all down to his level.

‘You are full of surprises.’

At first I thought it was Curze again – my sense of time and space was colliding but not connecting, making it hard to focus properly – but he never said that to me at Isstvan; he never said anything else after that moment.

No, it was Horus speaking. That cultured tonality, that deep basso which had made this treachery possible. Only he could have done it. I just didn’t know why. Not yet.

I opened my eyes at last and saw before me the patrician countenance of a once noble man. Some would call him a demigod, I suppose. Perhaps we all were in our different ways, but then gods were supposed to be superstition honoured by lesser, credulous men.

And yet here we all were. Giants, warrior-kings, superhuman in every aspect. One of us even had wings; beautiful, white, angelic wings. Looking back now, I cannot fathom why no one looked at Sanguinius and wondered if he were really a god.

‘Lupercal,’ I began, but Horus cut me off with a mirthless laugh.

‘Oh, Vulkan, you really were badly beaten.’

He was armoured in black, a suit I had only seen him wearing once before and which bore no resemblance to either the Luna Wolves of his origin, or the Sons of Horus that he led afterwards. As much as he wore it, the black also bled off him in waves like it wasn’t armour at all but some dark anima enclosing him. I had felt it before, caught some inkling of the man he was becoming, but to my shame did nothing to prevent it. An eye glowered in the midriff, blazing and orange like Nocturne’s sun but without the honest heat of natural fire.

He gripped my chin with a taloned power fist, and I felt the claws pinch.

‘What do you want with me? To kill me, like you killed my sons? Where is this place you have me imprisoned?’

As my eyes adjusted, healing through the gifts my exceptional father gave me, I saw only darkness. It reminded me of the shadow Curze cast over me when I was at his mercy on the plains of Isstvan.

‘You are right about one thing,’ Horus said, his voice changing as I grew more lucid, becoming gradually sharper and more rigid, ‘you area prisoner. A very dangerous one, I think. As to my purpose,’ he laughed again, ‘I honestly don’t know yet.’

I blinked, once, twice, and the face before me transformed into another, one I could scarcely believe.

‘Roboute?’

My brother, the primarch of the XIII Legion Ultramarines, had drawn a gladius. It looked ceremonial, never blooded.

‘Is that who you see?’ Guilliman asked, eyes narrowing before he slid the blade into my bare flesh.

Only then did I realise that I was unarmoured, and sense the fetters around my wrists, ankles and neck. The gladius bit deep, burning at first but then growing colder around the wound. It was sunk into my chest, all the way to the hilt.

My eyes widened. ‘What… what… is this?’

Breath knifed through my lungs, bubbling up through the blood rising in my throat, making me gurgle.

He laughed. ‘It’s a sword, Vulkan.’

I gritted my teeth, anger clamping my mouth shut.

His voice changed again as Guilliman leaned in close and I could no longer see his face, but felt his charnel breath upon my cheek.

‘Oh, I think I am going to like this, brother. You definitely won’t, but I will.’

He hissed as if savouring the thought of whatever tortures he was already concocting, and it put me in mind of soft, chiropteran wings. My jaw hardened as I discovered the true identity of my tormentor, his name escaping through my clenched teeth like a curse.

‘Curze.’

Persona non grata…

A figure armoured in crimson stumbled into the chamber as if through a cut in a veil, a literal knife-thrust that parted realities and allowed him to escape into blessed darkness.

Valdrekk Elias had been waiting in the sanctum, waiting for days for his master’s return. It was foreseen, his humbling at the Warmaster’s hands. It was known that Horus would challenge the Pantheon and it was known that his own father would forsake him. A martyr’s cause was not for him, however. He was destined for greater and everlasting glory.

So it had been told to Elias, and so he had waited.

Now he cradled a wretched figure in his arms, torn and broken, savaged by the very warriors who were meant to be his allies.

‘Blessed master, you are injured…’ Elias’s voice trembled, in fear, in shame, in anger. There was blood all over the floor. Rivulets of dark red ran into sigils marked upon the iron tiles, casting off an eldritch glow as each engraving was filled with blood.

Elias muttered to keep the lambent glow from growing into something he could not control. He doubted his master would be of any use at that moment. The chamber was a holy sanctum; blood should not be spilled there idly.

Head bowed, facing the floor, his master was shaking and mewling in pain. No… it wasn’t pain.

It was laughter.

Elias turned him over and saw the ruin of Erebus’s face, white eyes staring from a skull wrapped in blood-soaked meat. His red-rimed teeth chattered in a lipless mouth, clacking together in a rictus grin before parting as he breathed.

Elias looked at him aghast. ‘What has been done to you?’

Erebus tried and failed to answer, spitting up a gobbet of crimson.

Disciple lifted master, carried him in both arms despite the weight of his war-plate, holding his partly insensate form across his body.

Parting with a blast of escaping pressure and the whirr of concealed servos, the sanctum doors opened into a corridor. The apothecarion was close.

‘A lesson…’ Erebus croaked finally, gurgling his words through blood.

Elias paused. Blood was dripping with a steady plinkingrhythm as it struck the deck plates underfoot. He leaned in, the stink of copper growing more intense as he closed. ‘Yes?’

‘A lesson… for you.’

Erebus was delirious, and barely conscious. Whatever had been done to him had almost killed him. Whoeverhad done it had almost killed him.

‘Speak it, master,’ Elias whispered with all the fervour and devotion of a fanatic.

Erebus might have lost favour in some quarters, with his father certainly, but he still had supporters. They were few, but they were also ardent. The Dark Apostle’s voice shrank to a whisper. Even for one with Elias’s enhanced hearing, words were difficult to discern.

‘ Sharpen ours, blunt theirs…’

‘Master? I don’t know what you are saying. Tell me, what must I do?’

With a strength belied by his frail condition, Erebus seized Elias by the throat. His eyes, those ever-staring lidless orbs of pure hate, glared. It was like he was peering into Elias’s tainted soul, searching it for any vestige of falsehood.

‘The weapons…’ he gasped, louder, angry. He laughed again, as if this were a truth he had only just realised, before spitting up more blood.

Elias’s gaze went to the athame clutched in his master’s claw-like hand. It was only because the fingers were bionic that he still held the ritual knife at all.

‘Weapons?’ Elias asked.

‘We can win the war. They are all… that matters.’ He sagged, the Dark Apostle’s passionate fire finally usurped by his injuries. ‘Must have them or deny them to our…’ Erebus trailed off, falling into unconsciousness.

Elias was without compass. He didn’t know what to do, but trusted in the divine will of the Pantheon to guide him. Quickly, he took Erebus to the apothecarion and as soon as the Dark Apostle was on the slab and in the tender care of his chirurgeons, Elias opened a vox-channel.