Jaghatai Khan stood motionless, staring into the flickering, cold aperture of the attendant Iron Man's optical sensor. He hesitated for a long moment before finally speaking.
"If it is possible... hand him over to Lion later."
The Iron Man's response was instantaneous, devoid of hesitation.
"Perturabo is a high-risk target. In the past, we attempted to hand the captured World Eater Primarch, Angron, over to the Imperium, but he seized an opportunity to escape. It was a foolish and inefficient error. The Iron Men cannot sit idly by while such a lapse, a lapse that renders the established protocols void, is allowed to recur."
"All threats must be neutralized."
The machine's clinical finality left Jaghatai momentarily at a loss. He had not known that the Iron Men had captured traitor Primarchs more than once. Angron, in fact, had been taken twice. The first time, Khorne himself had intervened to spirit his champion away. The second time, at the behest of Roboute Guilliman, the Iron Men had wrongly placed their trust in a collaborator, surrendering their prisoner only to have his soul slip through their fingers.
This time, the Iron Men would not repeat the same mistake. Perturabo had to be ended.
However, the circumstances were unique, and Axion was in no rush. Each prisoner was held in an isolated, heavily fortified cell, shielded by layers of reality-warping dampeners and suppression fields. To prevent a prisoner from committing suicide to release their soul back into the Warp, Axion had even stockpiled Panacea outside each holding unit. As long as the physical host was preserved, their soul could not easily dissipate into the Immaterium.
Jaghatai contemplated this. Finding no logical grounds to contest the execution, he asked, "May I be the one to end the traitor, then?"
The attendant Iron Man's optical sensor pulsed.
"Request processed and approved. Prisoner: Perturabo. Executioner designation updated: Jaghatai Khan."
"Authorization complete. The prisoner will be delivered to the exterior hull in one hundred minutes for termination."
Jaghatai blinked, caught off guard by the machine's efficiency.
"Please follow me to the outer hull armor," the machine prompted.
Ectoplasmic dissociation weapons were brutally destructive. Unsure of exactly what power threshold was required to permanently extinguish a fallen Primarch, Axion had opted for the largest weapon class available. For this reason, the prisoner had to be jettisoned outside the ship's hull before the execution could be carried out.
...
Within the depths of the prison block, a team of Eight-Legs lifted the cage, transporting it onto an anti-gravity platform. After nearly an hour of transit, they deposited the cell into a cavernous hangar bay. Two more Eight-Legs moved in, performing a hasty modification to the exterior of the cage and installing a pressurized, atmosphere-regulated life-support module.
They then welded the cage to the underbelly of a Heavy Combat Drone. Once the nanite-constructs had fused the cage to the aircraft's chassis, the drone took flight.
Perturabo, his mental state still fractured and drifting in a fog of memory-trauma, lay prone in the cage, unable to move a limb.
Out in the void, the Heavy Combat Drone hugged the outer plating of the Void Sword, cruising at nearly ten thousand kilometers per hour for half an hour. Eventually, it came to a halt before a massive turret emplacement and waited.
The gargantuan turret sat upon a base more than twelve kilometers wide. It lacked a traditional barrel; instead, it bristled with countless interlocking, microscopic conduits. The muzzle presented a grotesque, shifting configuration of entangled geometries, pulsing with a cold, mechanical malice that radiated a palpable sense of annihilation.
This was a Titan-class macro-projector for ectoplasmic dissociation. A single discharge could unleash a beam several kilometers in diameter. Its articulated muzzle allowed the energy to be spread across a wider surface area or focused into a needle-thin strike for maximum penetration. While the efficacy of conventional energy-weapon design was often negligible against ectoplasmic threats, testing had shown that these destructive energies faced virtually no resistance when fired through such an apparatus. Axion was still unsure exactly how much the design improved the weapon's function, but it was undoubtedly the most efficient way to kill.
Meanwhile, inside the ship, as Jaghatai sped through the corridors aboard a hovering transport, he probed the attendant Iron Man for the intelligence extracted from Perturabo's mind.
The results were disappointing. Perturabo had remained in isolation since the end of the Horus Heresy; time within the Warp was erratic, and his memories did not span the full ten millennia. Analysis suggested that, for Perturabo, the Heresy had ended only three or four thousand years ago. He had spent the majority of that time tinkering with his fortress-world, lost in the rot of his own past.
He did not know that Leman Russ had entered the Eye of Terror, nor did he know the locations of the Dark Gods' personal domains. All his information came from his gene-sons. As masters of wargear, fortress-design, and siege warfare, many Warsmiths had carved out their own warbands, acting as technical consultants and arms dealers across the Warp, performing tasks much like the Dark Mechanicum.
Untethered from the constraints of the Imperium, the Iron Warriors, like their dark machine-cultist brethren, had unleashed their full potential. They developed technologies so blasphemous they defied comprehension. The most abhorrent of these was the "Daemonculaba," developed by the Warsmith Honsou. This vile technology transformed mortal women into living factories for the production of Iron Warriors recruits. They were forced to produce until they expired, their bodies and souls subjected to an eternity of torment under the erosion of Chaos.
Worse, the Daemonculaba could not only gestate new monstrosities but also mutate existing life. Honsou would cast powerful Chaos Space Marines or promising candidates into the Daemonculaba, using the intense concentrations of Warp energy to warp their genetic structure and physical form. The result was a being of greater strength and resilience, but one that had completely surrendered its sanity to become a thrall of Chaos.
Many traitor legions cooperated with the Iron Warriors, including the Thousand Sons. There were always renegade Iron Warriors seeking a way to master the psychic arts.
It was precisely this information that spelled doom for the remaining Iron Warriors. Within the prison block, the minds of every single captive Iron Warrior were scrubbed clean simultaneously, leaving behind a floor littered with the corpses of those whose brains had been literally cooked by the extraction process.
Benefiting from the Iron Warriors' tendency to mimic the Mechanicum, obsessively plugging themselves into ship systems and illicit devices, the Iron Men retrieved a wealth of accurate navigational data and signal signatures from their internal implants.
With no other viable leads, Axion decided to follow the, albeit unreliable, Aeldari prophecy and the analytical conclusions of the Primarchs present: the next objective was the Planet of the Sorcerers, Sortiarius.