Watching the synchronized battlefield feed, Jaghatai Khan felt a sense of lamentation mingled with creeping unease. Though he and Perturabo had always been distant, even for Primarchs, seeing a brother of his blood suppressed so effortlessly and reduced to a prisoner by a coordinated machine army unsettled him deeply. Yet, the power displayed by the Iron Men was far beyond the Imperium's ability to contest.
Ground combat had stalled the moment Perturabo was captured, not because the surviving Iron Warriors had repelled the Iron Men, but because Axion had terminated the offensive. The primary objective had been secured. Across the fortress-world, the Iron Men had captured 2,763 Iron Warriors and 443 Chaos sorcerers. As for the Warp-tainted mortal slaves, they had been dispatched to the Emperor for judgment before the campaign even concluded.
The Astartes and the malformed, rot-twisted sorcerers were escorted one-by-one onto transports by the machines. Perturabo, however, was transported in isolation. The Iron Warriors fleet that had departed the planet earlier to throw themselves into the fray now drifted in silence; their vessels were devoid of life. With Perturabo in chains, his luckless sons had lost their utility. Axion had no need for more captives. Unlike the Thousand Sons, whose ranks were saturated with psykers, the Iron Warriors offered little of value. They were not even suitable as components for psychic weaponry; the taint of Chaos had rendered their essence too corrupted, too chaotic to be of use.
"Executing troop recovery."
There were still remnants of the enemy deep beneath the planet's crust, but Axion had already begun to withdraw. The forces deployed to the surface were recalled, and the wreckage of lost machine-units was rapidly harvested. Aside from ruins and scattered viscera, every significant fragment of the mechanical legions was reclaimed. Minor losses were deemed acceptable. The long-term exposure to Chaos had rendered the metal of the Iron Warriors' wargear worthless; to purge and smelt it properly would require a return to realspace, and as this operation was not resource-driven, Axion saw no need to meticulously scour the battlefield.
When the remnants of the Iron Warriors emerged from the subterranean tunnels in a daze, they found the surface utterly desolate. Aside from scraps of metal mingled with gore, there was no sign that, only minutes prior, the world had been swarming with a terrifying machine host.
The Imperial forces in orbit were baffled by why the Iron Men had suddenly abandoned the slaughter to retreat. Their confusion, however, was short-lived.
Dozens of beams lanced out from the Void Sword. In the horrified gaze of the Imperial observers, the entire planet began to fracture. For anyone still clinging to the surface, the Reaper had truly arrived.
The strategy of slow, surface-level advancement was inefficient. Such planets, natural entities that existed within the Warp, clearly did not belong to the Imperium. Even during the height of the Federal era, humanity had rarely encountered such phenomena. This world lay too close to the exit of the Eye of Terror leading into realspace. If such a world could not be controlled, destruction was the only logical course.
Furthermore, the Iron Warriors had already warped it beyond recognition. An inch-by-inch search for every remaining enemy was far too slow.
Under the fire of the Iron Men's Titan-ship, the planet crumbled like a dying star. Every structure was annihilated. Eight hours after its discovery, the entire fortress-world was reduced to drifting debris. The spectacle was far more terrifying than the fire of an Imperial Exterminatus. Often, Exterminatus could not truly extinguish all life, especially on a world so heavily modified, riddled with subterranean facilities and deep-buried bastions. Even the fires of nuclear bombardment could not reach bunkers thousands of meters beneath the rock.
But the Iron Men's extinction was absolute. The entire planet was atomized into countless shards drifting in the void. Even then, the Iron Men did not cease their fire. Countless beams swept across every fragment of land larger than a kilometer. Had Caliban suffered such an assault, the Great Library would not have stood a chance. The act of slaying an enemy and then mincing their remains into dust, only to scatter them into the void, left the Imperial forces shivering in existential dread.
Jaghatai soon dispatched a request to the Iron Men and once again boarded the Void Sword. Guided by an automaton, he traversed corridors that felt hauntingly familiar until he arrived at a massive detention block. He had visited this place before with another brother, where they had confronted Yvraine, the emissary of Ynnead, who had once been held by the Iron Men. Now, he walked alone.
The number of cells had increased exponentially. In the largest chamber, a robust figure sat naked on the floor. The gravity field within the cell hummed with a violent, jarring frequency.
THUD. THUD.
The heavy, metallic footfalls of the Iron Men were distinct from the gait of any Astartes power armor. Perturabo, held within the cell, slowly opened his eyes and turned his head toward the source of the sound. As a master of mechanics, he could distinguish the make of any machine by its tread. But this gait, this resonance, it was unlike any machine he had ever encountered.
When his gaze fell upon the iconic, sleek plating and that familiar, weathered face, Perturabo closed his eyes again.
"Jaghatai. Hmph."
"Perturabo!"
Jaghatai's fingers instinctively clamped onto the hilt of his power sword. The sheer force of his grip caused the weapon to emit a subtle, protesting whine.
"What? Are you here to give me a demonstration on how to crush the hilt of your own weapon?"
Jaghatai could smell the foul cocktail of machine oil and the stench of Chaos power clinging to Perturabo. It was a mark of betrayal more nauseating than any physical wound.
"I came to see you only to ask if you know the whereabouts of Leman Russ."
Hearing that name again, Perturabo offered a twisted, mocking smile.
"Ha-ha! Jaghatai, what are you thinking?"
"What is so funny?! Perturabo!"
Perturabo suddenly lunged from the floor, coiled leg muscles springing into action, and fixed his bloodshot eyes upon Jaghatai with predatory intensity.
"Russ is long dead! Do you know what his last words were? 'Even the builder's hammer has learned to betray...' He died laughing in my face, with a sneer and a pity that was entirely unreadable!"
"Hmph. Do you think I would believe your lies, you fool?"
Jaghatai did not care for Perturabo's deceptions. Perturabo, however, sank back to the floor.
"Who is the fool? By what logic do you think I would know where Russ is, or why I would ever tell you, Jaghatai?"
Jaghatai took one final look at the prisoner before turning to leave. Perturabo's voice trailed him into the corridor.
"When you have the chance, give Sanguinius my regards... When his wings are ground away by the Emperor's chains, tell him that the builder's hammer always keeps a place reserved for the breaker…"
Jaghatai paused, his knuckles whitening as he clenched his fist, but he marched out of the chamber without looking back. As the blast doors of the corridor slid shut, Perturabo's mind raced.
As brothers, you never truly saw me. Father was like that, and so were you. Why is it that even that beast commanded such attention?
As Jaghatai departed, several mechanical units, which had stood as mere observers in the shadows, immediately began their work. Axion needed to extract the information from Perturabo's mind, and time was short.