Captain Evidandro returned to us a year and a day after vanishing in the tyranid-infested hell of the distant Corolis meatgrinder. He staggered naked from the Fractured Peaks wilderness to hammer on the rain-lashed adamantium doors of our fortress monastery.

At first we were astonished, all of us believing the captain was long-dead. But amazement rapidly gave way to suspicion. The captain was confined to our interrogation cells where the Librarians and Apothecaries of the Solar Tyrants questioned and probed for evidence of corruption. Many days passed, but nothing was found. Evidandro could give no account of where he had been for the past year but no taint was found. He was deemed pure and his return hailed as an Emperor-given miracle.

Evidandro was reinstated as captain of the third company, relieving me of command and returning me to my previous rank as sergeant of the first squad. Orfes, my second, gave up his sergeant rank and rejoined my squad without complaint.

‘Evidandro, back from the dead! A miracle! Who’d have believed it!?’ laughed Orfes, slapping me on the back.

‘Certainly not me,’ I said, forcing a smile.

I watched the captain in the practice cages as our cohort drilled beneath the proud banners of the Solar Tyrants third company. One hundred space marines in a confined space is an assault on the senses, but I was deaf to the war cries and clanging ceramite. I stood to the side, unconsciously twirling my adamantium combat blade in my fingers as I watched the captain spar. His swordsmanship was not as I remembered it. Something about it lacked his unique flair. Like he was repeating rote-learned moves without having lived them. My blade turned over in my fingers just as thoughts turned over in my mind.

The Epistolary Samandriel approached me, force staff in hand, eyes tired from many days with the captain in our deepest dungeons. I knew he was a friend of Evidandro from their time in the initiates, maybe even before.

‘Settling back into your old role, Sergeant Helgarth?’ he asked. I nodded, not taking my eyes from the captain. Samandriel stood with me for a moment. ‘If you see anything strange, tell me.’

‘Of course,’ I said after a moment’s thought, turning to face the librarian. But Samandriel had already gone.

I looked back to the captain. It certainly looked like him. He had the livid scar across his torso from that lucky Aeldari blade strike. He had the ceramite plate on his head from Ork shrapnel. But I knew it could not really be Evidandro. This captain had no mark on his neck from where I slit his throat one year ago.

That evening I padded softly down the tallow-lit corridors of our monastery dressed in the simple pale robes of our order. I knocked on the door and Captain Evidandro greeted me warmly at the threshold, and invited me into his chambers. Weapons and battle honours, recently returned from a place of honour in the reclusiam, sat in piles around his room. A new suit of power armour stood proudly on a stand. He was starting to piece his life back together.

‘Where have you been, captain?’ I asked. Evidandro sighed.

‘Truthfully, I do not know, brother. I remember the Corolis campaign, the battles against the Great Devourer, and then…’ Evidandro’s brow furrowed. I tensed. ‘…and then…nothing. No memory until I found myself outside these walls.’

I forced myself to remain calm, keeping my heartrates in check. The captain would sense the alchemical musk of combat readiness.

‘And you’re…pleased to see me?’ I asked. Evidandro looked at me quizzically. He reached out for my arm. ‘Why wouldn’t I be, old friend?’

I whipped my combat knife from under my robes and drove it up through his jaw and into his head in a lightning fast strike, killing him instantly. He didn’t even have time to blink. It all played out as before. His blind trust in me had failed him again. That same lack of ruthlessness that I knew meant he did not deserve his rank. Maybe this really was the captain I mused as I withdrew my blade and lowered the corpse silently to the floor. Still, he was most definitely dead this time.

I stood a moment in his chambers, watching as blood pooled amongst his personal effects. It’s true, I had been unnerved by his sudden reappearance, but had I acted rashly? Not as much planning this time, but I could not risk the captain suddenly regaining his memory. He was either a threat to the chapter, or a threat to me, and I could countenance neither. Last time I had a warzone crawling with tyranids in which to dispose of the body. But my chances of smuggling a transhuman corpse through the fortress monastery were essentially nil. 

But Epistolary Samandriel had given me a way out. There was a story to be spun here. I had watched, I had suspected, I had confronted Evidandro…and then the captain – revealed as an imposter – had attacked me. The Epistolary was a skilled telepath, but there was a kernel of truth to my tale. Would that be enough? I had concealed much already, so I had to hope.

I slipped from the chambers and immediately ran into Epistolary Samandriel. Orfes was there too, and Areth and a number of other third company veterans, filling the stone corridor with their armoured bulk.

‘Epistolary. I…’ the words died on my lips. I glanced back into the chamber. Captain Evidandro’s corpse was gone. He had never returned. The illusion had ended.

‘Restrain him,’ said Samandriel, his eyes no longer tired.

And the rest, well, you know the tale from there. This is my testimony for the chapter archives. Know that all I did was for the good of the Solar Tyrants and I regret no part.