The First Heretic

twelve years of sharing battlefields. This last was a Conqueror, and the primus unit of the group. It wore a Legion banner over its shoulder, and its armour plating was etched with Colchisian runes.

Several of the Word Bearers saluted this last robotic warrior. It didn’t acknowledge them.

–Incarnadine– the Conqueror declared in a voice devoid of personality, –standing ready– .

Xi-Nu 73 turned to the gathered Word Bearers, his eyes refocusing yet again. ‘Greetings, sergeant. Ninth Maniple of the Carthage Cohort, awaiting orders.’

Argel Tal hit the ground running, the boosters on his back cycling down as he ran. Both blades were sheathed; in his fists, a richly-inscribed bolter bucked with each fired shell. He took refuge with several of his warriors in the lowest level of a glass tower, shooting out of the stained glass windows. Whatever patterns the coloured glass once held were gone, smashed through by Word Bearers needing clear lines of fire.

The Obsidian in the street outside dwarfed them all, liberally blasting the road with streams of electrical force from its featureless face. Argel Tal reloaded, and as he slammed a fresh magazine home, he had a momentary glance of a glass shard by his boot – a fragment of the stained glass window showing a figure in golden armour.

Dagotal Squad was running interference, weaving between the artificial’s insect-legs, veering and jinking to avoid its lethal arcs of fire. Bolter shells hammered into its joints from where Torgal’s men took what cover they could find, but their efforts were little more than an irritant.

‘Xi-Nu 73,’ Argel Tal voxed. ‘We’re in position. Make this fast.’

‘Acknowledged, Seventh Captain.’

They came from behind the construct, emerging from a subsidiary road. Sanguine and Alizarin stalked forward first with all the grace of stumbling beggars, their movements a stark contrast to the liquid grace of the enemy machine. Lascannon fire streamed from the shoulder mounts of both Crusaders, carving searing scars into the Obsidian’s skin, the sludge-gleam of melted glass bright against the black. Their arm-blades came up on clanking, motorised hinge joints, slicing down to chop at the construct’s legs.

Recognising this new threat, the Obsidian span to face the Mechanicum war machines. It turned into a barrage of gunfire, shoulder-mounted heavy bolters punching shards from the construct’s face and torso with a torrent of explosive shells. Incarnadine, regal in form compared to its brothers, tracked every movement made by the enemy machine. It didn’t cease fire, even for a second. Nor did a single shot go wide.

The Obsidian’s storm-stream wasted itself, blasting up at the sky as the Mechanicum robotics knocked it off- balance.

The Cataphract-class Vermillion, as bulky as an Astartes Dreadnought, was an altogether more ponderous engine. Stocky and lumbering, it closed the distance as the Obsidian sought to right itself on its four remaining legs. Siege hammers swung in, meeting alien glass with a thunderclap’s refrain. Four legs became three – the glass machine crashed to the knees it had left.

‘Finish it,’ said Argel Tal. His jump pack burned again, groaning as the engines drew breath.

‘By your word,’ came the vox-replies.

The swords came free in smooth pulls, and Argel Tal let a short burst of thrust carry him skyward. Even prone, the Obsidian offered no purchase. As the Word Bearers came down in its back, most elected to hover, burning their jump jets rather than standing upon the thing’s body. Swords clashed and carved, but only Argel Tal’s empowered blades inflicted significant damage, sending shards of dark glass flying with each hack.

Even as it died, the Obsidian dragged itself across the street, a grasping hand reaching for the closest true threat. Incarnadine stepped back, autocannons laying into the outstretched hand, shearing fingers from the fist. Behind the Imperial war machine, Xi-Nu watched with unwavering attention, occasionally adjusting dials on his chestplate for reasons none of the Word Bearers had ever discerned, despite a decade of fighting by his side.

When the Obsidian lay still at last, Argel Tal and Dagotal came over to the tech-priest. The downed enemy construct had a shapeless resemblance to a melting ice statue, its body ruined by a thousand bullet impacts, blade cuts and lascannon beams. Both Word Bearers crunched closer on the glass shards lining the road.

‘Greetings, captain,’ said Xi-Nu 73. ‘Ninth Maniple of the Carthage Cohort, awaiting orders.’

Cyrene paused Argel Tal’s retelling with a hand on his forearm.

‘You used artificials yourself?’

He’d been expecting this. ‘The Legio Cybernetica is a treasured facet of the Mechanicum. The Great Crusade leans heaviest on the Legio Titanicus for their war engines, but Cybernetica plays its role among the noblest Astartes Legions. Their artificials are robotic shells housing machine-spirits. Cybernetica tech-priests engineer organic-synthetic minds from biological components.’

Cyrene reached for the glass of water on her bedside table. Her fingers slid across the metal surface, bumping the glass gently before she got a grip. When she drank, it was in little swallows, and she seemed in no rush to speak again.

‘You don’t see the difference,’ Argel Tal said, not quite asking.

She lowered the glass, facing him without seeing him. ‘Is there a difference?’

‘Do not ask that question to Xi-Nu 73, should your paths ever cross. He’d be insulted enough to kill you, and I would be vexed enough to kill him in return. Suffice to say, the difference is in the mind. Organic intelligence, even synthetic in nature, is still tied to the perfection of humanity. Artificial intelligence is not. That’s a lesson many cultures only learn when their machine slaves rise up against them, as the Obsidians would have done one day, to the people of Forty-Seven Sixteen.’

‘You always say we are perfect. Humans, I mean.’

‘So it is written in the Word.’

‘But the Word changes over time. Xaphen tells me it’s changing even now. Are humans really perfect?’