'Come on!' I roar at the beast. 'Come on, hell-spawn! Face your death!'

Incredibly, it has grown wary of me. I don't think that I could destroy it with my modest short sword alone, but it definitely doesn't seem to want another taste of the blade.

Then, the monster does exactly what I don't want it to.

The crunching footfalls retreat the thing is leaving. It has tired of playing with the blinded toy that hurts it every time, and there is other prey taking flight through the tunnels of the Penetralia. Prey that can be horrified into oblivion by the monster's ghastly appearance.

I swing my sword and shield about me wildly, smashing more of the statues to pieces, hoping to entice the monster back. I fail.

Sheathing my blade, I reach out with one gauntlet and stumble for the rocky reassurance of the temple-chamber wall. I have to find my way back to the terminus. I cannot risk taking off my helm this could be a trick, and the beast could be waiting for just such an opportunity.

I have no real idea what it is capable of. It follows no theoretical that I can recall.

So I make the lonely, stumbling trek back through the Penetralia Pelion the Lesser, lost in a labyrinth, lost in the darkness outside of my war-plate, and trapped in the darkness within. A deeper darkness, if ever there was one.

Pushing myself off one tunnel wall and scraping to another with my shield outstretched, I try to retrace my route through the winding maze of caves and passageways. It seems to take an eternity, knowing that every step of the way the beast could be ghosting my clumsy footfalls, and knowing equally that the monster could have reached Phornax and Dodona by now. Knowing that it could have them, before they have chance to power up the mag-lev engine and make their submerged escape.

I would warn them, but for the severance of my vox-link. I hurry, but my haste is enemy to my intention. I stumble. I fall. I get up. I feel my way on.

I know that I have reached the terminus chamber when I hear the water the lap of the lake against the rocky shore. In my blindness, sound has become my greatest guide. I stop, and I listen.

I can hear movement. Something paces the moist rock of the shoreline. Beyond that, I detect breathing. Shallow, terrified breathing. Not the sound of a Space Marine.

'Dodona!' I call out. Without my vox-grille, I'm forced to shout through the ceramite shell, and the sound of my voice pains my ears after so long spent in the quieted darkness.

'Pelion?' she responds with gasping relief.

It's a question. She can't see me. The chamber must be in darkness. I approve. The lack of light, be it accidental or intentional, has saved her.

She moves, ever so slightly. There is a slurp and splash of water. She's kneeling in the shallows, hiding in plain sight.

I hear the beast's pace quicken. It knows where she is. It wants her to see it.

'Pelion,' Dodona whispers through the darkness. Her voice trembles. She must be cold in the water. Cold, and out of her mind with human, mortal fear. 'It's here...'

'I know,' I call back. 'Brother Phornax?'

'He's gone.'

The thing ventures into the water, its infernal legs carrying it through the shallows towards her.

'Ione,' I say, stumbling forwards along the wall of the terminus. I, too, am making for the groundwater lake. 'Ione, I want you to stay perfectly still. Do you understand?'

'I'm so scared,' she replies, the honesty falling out of her.

'I know,' I try to reassure her. Then I lie. 'Me too.'

There, in the darkness of the cave and in the darkness of my helmet, I reach a conclusion. It is not enough to escape. To run for reinforcement. To flee and take the word to others that they too should flee. I am an Ultramarine. An honoured champion. Otherworld monstrosity or not, it is my duty to end this beast.

Regardless, it is between me and my only exit. The thing must die.

As Space Marines, we are taught and trained to make the most of any advantage that the immediate environment has to offer. I think on the mag-lev engine, and the damage it might visit upon the beast. I think on the millions of tonnes of rock hanging above us, and how I might bring it down upon the monster to crush the unlife from it. The darkness defeats me here the daemon will not oblige me by standing in front of the tram, and if there were mining demolitions somewhere in the terminus chamber, there is no way I could find them. I discount these desperate strategies.

I think on the darkness. I think on the light.

The light...

'I need you to do something for me, Ione,' I call out.

'Yes?'

'When I tell you to, close your eyes, and dive for the bottom.'

'I can't swim!' she protests, one fear replaced by another.

'You don't need to swim. Just stay under for as long as you can. Can you do that?'

'I can't swim,' she repeats. 'Staying under the water won't be a problem.'

I listen to the monstrosity this thing of hideous darkness that Ungol Shax has inadvertently unleashed upon the world. It strides through the shallows with predatory intent. It closes on the terrified Pioneer. I sheath my sword. I rest my shield against the wall.

I am ready.

'Now!' I bellow. I hear her go under. The dive is messy and uncertain; there is splashing, and then nothing. She is beneath the surface.

The beast splashes too. It is searching the shallows for its prey, staring down into the dark water.

I reactivate my suit lamps.

Abruptly, the movement ceases.

Everything grows still. For an agonisingly long moment, I wait, listening to the faint lapping of the waters. I go to remove my helmet, but caution stays my hand.

I wait. I wait to confirm what I already know. The Legiones Astartes are not particularly blessed with imagination. Tactical ingenuity, perhaps. Creativity in the construction of strategic defences. An inspiration of the moment, guiding our hand in the confusion of combat. We leave notions of fancy and the elegance of creative representation to the delicacy of the human hand. I remember admiring the paintings of Priscina Xanthoi, remembrancer and artist on the Twelfth Expedition. I did not communicate any such sentiment to Xanthoi herself or my superiors; but staring at her paintings, her visions, her interpretations, I feared that I might lose myself within them. Her beautiful depictions of our early accomplishments, both bloody and bright, had an incredible life and interiority. She told our story in her portraits and vistas. When age began to claim her and she was summoned back to Terra, I felt that the expedition lost a little of its remembered grandeur. Our achievements never seemed so noble as when they were viewed through Priscina Xanthoi's incredible eyes. They certainly haven't since.

When finally I open my eyes to the gloom of the terminus chamber, I come to wonder how the remembrancer would have painted the monstrosity that stands in the shallows before me. Would she have given it eyes, a mouth, or even a face? Perhaps her gyrinx-hair brushes might have been able to capture its full, ethereal horror. The alien nature of its existence and the revulsion of reality itself about its immaterial form. Perhaps she could have done mind-scalding justice to its chthonic grotesqueness and freakery.

I cannot imagine such a nightmare. Unfortunately, I don't have to.

Ione Dodona erupts from the water, her lungs bursting to breathe the cold air again. She devotes her first lungful to the most horrified, soul-churning scream I have ever heard in my long and war-filled life. Screaming is good. Screaming means that at least she is still alive.

My suit-lamps are casting the terminus chamber in a bleak light light enough for the daemonic monster to have caught sight of its own reflection in the undisturbed surface of the lake.

There is also light enough for me to see Ione Dodona stumbling backwards through the water, away from the statue of the beast, crafted in shadow.

She is still screaming.

I approach the indescribable horror of the crystalline thing it is a horror beyond imagining. I fight the involuntary inclination to look away, and force myself to behold the beast. My eyes sting at the sight. I stumble. I feel my mind reel. I plunge through the glass floors of insanity. Reaching out for my training, the stunted nullification of emotional-limitation, the solid grounding of psycho-indoctrination, I claw my way back into the moment.

I am Hylas Pelion. Pelion the Lesser, Honorarius of the XIII Legion, 82nd Company.

My being floods with hatred for my enemy. It had no right to exist in this universe.

Ione Dodona is still screaming. The Pioneer is lost. Even petrified, the daemon-form was too much for the fragility of her all-too-human mind. I think of the battle for Calth, the war beneath its surface and the greater war that must surely follow. This, then, is the shape of the enemy to come. Increasingly, the Emperor's true subjects and servants will face evil in such forms, brought forth from the beyond by our brothers in darkness.

Common humanity is not ready for such visions. Madness will find them, like it has found Ione Dodona. She screams and she screams, her mind broken. Perhaps it would be a kindness to spare her this torment?

I pluck my single remaining shell from where it is mag-locked to my belt. I shake the bolt round about the inside of my armoured fist. Like a die, it rattles. Like a die, it awaits an outcome. An outcome unknowable in the enclosed space of my gauntlet, a realisation it can only find in the breech of the pistol that sits brusque and empty upon my belt. I draw the pistol and thumb the bolt into it.

The weapon comes up, level with both the crystalline abomination and the screaming Pioneer. The muzzle drifts between them. My ceramite fingertip finds its way to the trigger, and both I, Pelion the Lesser, and the weapon find our way to realisation.

'I was out hunting when I saw them. They was... I don't know what they was. Flesh in all the colours of the rainbow, changing, shifting. Dozens of mouths, moving about on their bodies, spewing fire, setting the trees alight. The forest was burning. And they was floating. I tried to bring them down, but las-fire didn't do nothing. Didn't even break their skin. Got their attention, though.

'I ran. I ran so fast. Needed to get back to Melora. Not fast enough. There were more of them, and the cabin was burning. I heard her screaming.

'I don't know what they are, but I know I want to help you take them down. Not for the Emperor or whatever-his-name-is Guilliman.

'For Melora.'

We are supposed to know no fear.

These are not just words. To know no fear is the core of the bio-alchemical secret worming its way through the invisible threads of our genetics. We are born to fight and die, never knowing fear. We understand it. We endure it. We conquer it.

But we never suffer it, and thus we never know its true taste. Fear is nothing more than a biological reaction, a physiological curiosity that afflicts lesser beings with various degrees of cognitive impairment.

This is merely the first step. First, one must know no fear. Next comes the conviction of courage: giving one's life to the absolute purity of purpose. To rise into the ranks of the Legiones Astartes means casting all else aside. Your family is dead. Your youth is meaningless. As far as the galaxy is concerned, you were never born. You forfeit any lingering pretensions of humanity.

One warrior is nothing. The Legion is everything.

You have to live by that code. You have to embody those words, and ensure every indrawn breath is devoted to making them true.

As a Space Marine, you are no longer human. You are a legionary beyond the concerns of mortality and into the genetic purity of the transhuman. You stand clad in your Legion's colours, carry your Legion's symbol, and serve your Legion's lord. You wield weapons forged in your Legion's foundry-fires. You live and breathe and sweat your Legion's culture, drawn from your Legion's home world, manifested in your Legion's traditions and rituals.

Above the legionary is the squad the pack, the claw, the unit, the cell. Above the squad is only the Legion. This is strength. This is duty.

Duty must blunt all other emotion. The Legions are weapons, nothing more warriors forged for war, no different from a ploughshare melted down to become a sword. Swords know no fear, and feel no emotion. They do not pine for the days of tilling the soil in peaceful fields, nor do they break before the first blow is even struck. The Legions, and the once-humans that make up their ranks, are the same.

But the human mind is never a clean sheet. Even taking a child's mind before the realities of life teach a man to settle, to compromise, and to know his limits a wealth of lore already colours the mind's canvas. We are not mindless weapons, and a divorce from humanity does not mean we are wholly inhuman. Humanity is our foundation, a limitation to be built upon. Therein lies the perfect strength of the legionary's form and function. The Emperor, for all his ignorance, got so much right. We are the weapons the human race needed to lay claim to the stars neither human nor inhuman, but something beyond both. Transhuman, or post-human, as some of the scribes say. Or perhaps once-human is closer to the truth.

However, as with anything touched by humans, the process is not without flaw. Some minds resist the ascension from boy to legionary, and some things are carved too deep to simply be planed away while forging the psyche of the perfect soldier. Sometimes, too much of the man remains inside the soldier. These are the unlucky and flawed, the chaff that falls from the wheat. Imperfect cogs in the perfect war machine.

Most never last long enough to stand clad in ceramite at all, let alone march beneath the Imperium's banners. The Legions are brutal flesh-factories, and their trials cull the weak from the strong. To be Legiones Astartes, you must know no fear and live a life of absolute duty, to a greater ideal.

Perhaps in the future there shall be some refinement or alteration of the process, something that steals the underlying humanity that forms our foundation. If so, I would not envy the diminished generations that would follow us.

For now, there is no sure way to murder the human spirit at the heart of every warrior. Only a fool would want to.

But I am not certain the lords of every Legion would agree with me.

handwritten treatise, author unknown Out of ammunition and out of luck, Kaurtal knew he had finally reached safety when he found the firelight.

The light of a humble wreckage fire caught the silhouettes of the living and the dead, painting their shadows across the cave walls. The humans were hunched, spindly things, thinned by malnutrition, bent over by wounds and weariness. Most were ravaged by radiation burns long before they had made it down into the tunnels, and they bore the Mark of Calth written in pain across their deteriorating flesh. Their shadows were careless marionettes, stunted and graceless as they danced across the stone walls.

Kaurtal's own image a towering warrior with a helm crested by twin horns showed a stark, dark grandeur that he no longer felt. His shadowy avatar displayed none of his armour's battle damage, nor any of the weariness that sank through his body to the bone.

The connection feed sockets running up his spine were aching drill-holes that cried out for tending. The same feeds along his shoulders and chest, where his armour linked to his genhanced physique, were punctures in his flesh, pulling raw with every movement.

He knew exactly how long he had been here. He knew it, despite the fact he lived in a world with neither day nor night, because his eye lenses' runic display kept track of every hour, every minute, every second he spent down here in the dark.

He had lost his own bolter six years and two hundred and forty-six days ago. In that time, he had carried another thirteen bolters, looting them from the fallen and inevitably losing them again when the fighting was at its most savage.

For several moments, he watched the shadow-play performance sliding over the ancient rock. His own image mocked him as it flickered against the cavern wall. Winged. Horned. The sight his enemies saw. The sight his enemies had seen for almost seven years.

'Lord,' the pack of scabbed, bloody wretches called to him. 'Lord. Great lord, please. Your blessing, lord.'

Incredible. Desperation had them believing that he cared about their lives.

Kaurtal ignored them all, moving to the hulking figure at the rear of the cavern. More of the dregs and survivors scattered before him, their shadows dancing across the walls in devilish haste.

The figure greeted him from the darkness, doing him great respect by acknowledging him first. Its eye lenses were the same blue as the drought season sky above the City of Grey Flowers, back home on Colchis. It stood in the motionless drone of active armour; its helm tusked, its great shoulders speaking of monstrous, inhuman strength. To Kaurtal, it was merely a warrior in Cataphractii plate. To the humans that served it, it was a killer made in the image of a hunched and long-forgotten primate godling. Its voice was a vox-growled expulsion of thunder on the horizon.

'Jerudai Kaurtal,' it said. 'You still live.'

Kaurtal nodded, with a hum of his own armour joints. 'So it seems.'

The Terminator lifted a ponderous claw. It might have been a welcome.

'And so our paths cross once more,' it said, 'on the two thousand, four hundred and fortieth day.' No surprise that Thuul cited the exact day, as well. They all counted the days. It was how the Word Bearers greeted one another. 'Are you the last of the Twisting Rune?'

Kaurtal was not sure. He had seen none of his Chapter in weeks. Exactly fifty-one days, to be precise, and those he had found had been bodies going to rot in an otherwise abandoned cave.

'I believe I might be,' he admitted. 'We should speak.'

The Terminator was silent for several seconds before replying. 'Then speak.'

'Not here.' Kaurtal gestured to the slaves.

The two Word Bearers moved further into the cave, and into a tunnel leading away from it.

'Thuul,' he said to the Terminator. 'How do you tolerate them? How do you endure the whispers and the weeping, night after night? Their prayers scrape my ears.'