‘Come on!’ the one with the axe shouted down at me. ‘Come on!’

My armoured frame obliged, responding to the goad with chainblades spinning.

When I passed another corridor that crossed with the one I was in, I realised what the veterans had done. My puppeteer did not.

As I reached the crossroads, heading blindly at the three men who were shouting and jeering a few metres beyond the junction, a second group of prisoners sprung the trap. A spear thrust grazed my ribs and I grimaced. It went on into the metal vambrace encasing my left arm, severing some cabling. Oil and fluid began to vent furiously.

Just as I was turning to face my first attacker, a second axe weighed in and embedded itself in my right hip. It bit into my flank but the armour bore the brunt. My chain-blade tried to lash out but the cabling snapped and the armature fell limp.

A stern-faced legionary looked up at me, pulling his spear back for another thrust. He wore the black and white of the Raven Guard, through his armour and iconography had seen far better days. My still functional right arm whipped around and took off the warrior’s head before he could attack again.

As the black, beak-nosed helmet bounced off into the darkness, my search lamps flickered and all of the ambushers attacked me at once. I spun, opening up two of the veteran troopers and spilling them out onto the metal deck. The third stooped to pick up his comrade’s fallen club, but my leg snapped out before he could grab it. The impact hit him square in the chest. I heard ribs break and watched him half spiral down the corridor before crumpling in a lifeless heap.

My last opponent struck again, focusing on the damaged arm, which was spitting sparks and spraying oil. Another legionary loomed into my eye line. My heart sank when I saw the colour of his battle-plate.

Emerald-green.

He was broad-shouldered, the faded insignia of the 15th company emblazoned on his dented pauldron.

Nemetor…

I had believed he was dead. Curze had saved him. He’d done it so I was the one that butchered him.

Entombed in the machine, I was unrecognisable to my son. Ducking a hopeful swipe of my remaining chainblade, he hacked into my left arm and jolted some of the pins impaled in my nerves loose. Some feeling returned, and I found I could move the arm again. Watching Nemetor’s hope turn into horror as the weapon he thought he’d destroyed began to move as I lifted it, I then turned the buzzing chainblade on myself. Momentum from my frenzied machine’s attacks drove the saw into my body, first cutting metal, then flesh.

I let it gore me until darkness began to crouch at the edge of my vision, until death, however brief, reclaimed me.

‘Clever,’ I heard the voice of my brother say.

I blinked, opening my eyes and saw the death machine had been removed and that I was back in my cell.

‘I stand both impressed and disappointed,’ he said.

At first I saw armour of cobalt-blue, trimmed with gold; a firm and noble countenance, framed by close-cropped blond hair; a warrior, a statesman, my brother the empire builder.

‘Guilliman?’ I breathed, hoping, my sense of reality slipping for a moment.

Then I knew, and a scowl crept onto my face.

‘No… it’s you.’

I was sitting with my back against the wall, looking up murderously at my brother.

Curze laughed when he noticed my expression.

‘We’re getting close now, aren’t we?’

‘How long?’ I croaked, tasting ash in my mouth and feeling a fresh brand in my back.

‘A few hours. It’s getting faster.’

I tried to stand, but was still weak. I slumped back.

‘How many?’

Curze narrowed his eyes.

I clarified my question, ‘How many times have you tried to kill me?’

My brother crouched down opposite, within my reach but betraying no concern about retaliation for what he had done to me, what he continued to do to me. He nodded to the wall behind me.

I turned to see my reflection mirrored in obsidian. I saw Curze too, and Ferrus Manus, now little more than a walking cadaver in his primarch’s armour, standing just behind him.

‘You see them?’ He pointed to the numerous honour scars branded into my back. Some stood out from the others, a clutch of more recent brandings that I had no memory of and could attribute no oath to.

Curze leaned in and whispered into my ear, ‘A fresh scar every time, brother…’

There were dozens.

‘Every time, you returned to torment me,’ he said.

I faced him. ‘Torment you?’

Curze stood, his armoured form casting a shadow over me from the low light in the cell. He looked almost sad.

‘I am at a loss, Vulkan. I don’t know what to do with you.’

‘Then release me. What is the point of killing me over and over again if I cannot die?’

‘Because I enjoy it. Each attempt brings with it the hope you will stay dead, but also the dread that we shall be forever parted.’

‘Sentiments of a madman,’ I spat.

Curze’s eyes were oddly pitying. ‘I think, perhaps, not the only one. Is our dead brother with us still? Is Ferrus here?’

At the mention of his name, the cadaver’s mouth gaped as if amused. Without eyes or much flesh, it was hard to tell.

I nodded, seeing no point in hiding the fact I saw the undying effigy of Ferrus Manus.

‘I thought so,’ said Curze, unable to shake his melancholy. ‘Our father gave you eternal life. Do you know what he gave me? Nightmares.’ His mood darkened further, his face transformed into genuine anguish. For a moment I caught a glimpse of my brother’s true self and despite all that he had done or claimed to have done, I pitied him.

‘I am plagued by them, Vulkan.’ Curze was no longer looking at me. He regarded his reflection in the obsidian instead. It appeared to be something he had done before, and I imagined him then, screaming in the darkness with no one to hear his terror.

The Lord of Fear was afraid. It was an irony I thought Fulgrim would appreciate, twisted as he was.

‘How can I escape the dark if the dark is part of what I am?’

‘Konrad,’ I said. ‘Tell me what you see.’

‘I am Night Haunter. The death that haunts the darkness…’ he answered, though his voice and mind were far away. ‘Konrad Curze is dead.’

‘He stands before me,’ I pressed. ‘What do you see?’

‘Darkness. Unending and eternal. It’s all for nothing, brother. Everything we do, everything that has been done or will be done… It doesn’t matter. Nothing matters. I fear. I amfear. What kind of a knife-edge is that to balance on, I ask?’

‘You have a choice,’ I said, hoping that some fraternal bond, some vestige of reason still existed in my brother. It would be buried deep, but I could unearth it.

He turned his gaze upon me – so lost, so bereft of hope. Curze was a mangy hound that had been kicked too many times.

‘Don’t you see, Vulkan? There are no choices. It is determined for us, my fate and yours. So I make the only choice I can. Anarchy and terror.’

I saw it then, what had broken inside my brother. His tactics, his erratic moods, were all caused by this flaw. It had led him to destroy his home world.

Dorn had seen the madness lurking within him. I suppose I had known it was there too, back on Kharaatan.

‘Let me help you, Konrad…’ I began.

Pale like alabaster, eyes dark like chips of jet with about as much warmth, Curze’s face changed. As the thin, viper’s smile crawled over his lips, I knew that I had lost him and my chance of appealing to what little humanity still remained.

‘You would like that, I think. A chance to prove your nobility. Vulkan, champion of the common man, most grounded of us all. But you’re not on the ground, are you brother? You are far from your beloved earth. Is it colder, here with me in the dark?’ he asked, bitterly. ‘You are no better than me, Vulkan. You’re a killer just the same. Remember Kharaatan?’ he goaded.