The Astartes of the Iron Hands held mechanical power in the highest esteem. Not only was every battle-brother a de facto Techmarine, but they shared the Adeptus Mechanicus's obsessive drive for the augmentation of the flesh. To excise the biological and replace it with superior bionic prosthetics was their most sacred and common practice.
As the Iron Hands leveled their weapons at their Iron Man allies, the Sapient Machine Automaton who had struck first stepped forward. It lowered its chassis, peering with a curious, analytical gaze at the severed metallic limb.
The power armor was being rapidly consumed by rot; the bionics within had fared no better. The sacred unguents and biological nutrient fluids had been instantaneously corrupted, sprouting clusters of grotesque, pallid fungi.
Witnessing this, the Iron Hands warriors immediately grasped the logic behind the Iron Man's cold intervention. They lowered their bolters, casting apologetic glances toward their allies. The Iron Men, however, possessed a singular aloofness that defied mortal understanding; Axion remained indifferent to their change in heart.
To the machine mind, the phenomenon before it was fascinating. Inorganic matter undergoing rapid, forced conversion into organic biomass?
Another Sapient Machine Automaton detached a secondary manipulator arm from its frame. Using the spare limb as a probe, it hoisted the twisted, rotting leg to examine it. It became evident that the warrior had stepped into the ichor spilling from the shattered monstrosity. The corruption began to crawl across the automaton's armor plating until its energy-sight detected a localized anomaly.
Tossing the severed limb aside, the automaton used the detached manipulator to touch the gore remaining on the deck. The mechanical arm suffered minor corrosion, though the effect was significantly less pronounced than it had been on the Astartes. Once the peculiar blood was wiped from the tool, the rot ceased its expansion.
Nearby, the two Destroyer-class automatons were inspecting their own power claws. When they had torn the vault doors asunder, their massive talons had pierced deep into the Warp-beast's form. However, thanks to their active power fields, no trace of the filth had clung to the massive weapons.
To verify a nascent hypothesis, the machine entities began a series of maneuvers that left the Iron Hands in a state of bewilderment.
Led by the Sapient Machine Automatons, four different types of machine entities stepped onto the mangled remains of the Nurgle daemon one by one, intentionally coating themselves in the Chaos-tainted blood before standing aside. Three other automatons then began a meticulous diagnostic sweep of the four subjects.
Axion quickly synthesized the data into a simple conclusion: the higher the physical quality of the machine's alloys, the greater its resistance to this twisting corruption.
The daemonic blood that had instantaneously infected the Iron Hands Astartes caused no reaction in the Armored Wardens or the Destroyer-class automatons; to them, it was as inert as common water. The Sapient Machine Automatons, constructed of lower-grade materials, suffered slight surface corrosion, while the Automated Sentry-Troopers could withstand direct contact with the filth for several hours.
Satisfied, the machines detached the contaminated surface components and discarded them in a pile. A Destroyer-class automaton ignited its plasma incinerator, reducing the tainted parts to a pool of molten slag. The terrifying intensity of the heat left the Iron Hands in awe. Despite having served alongside the Iron Men in numerous escorts and engagements, they had rarely seen the Destroyers utilize such weaponry. The Imperium required functional cities, not scorched ruins.
But on this dead world, such restraint was irrelevant. The molten metal and the patches of vitrified earth would eventually cool; the automatons would reclaim the solidified alloys upon their return.
After purifying the daemonic remains with flame, the Destroyer-class automatons took the lead, marching into the mountain facility. The interior was cavernous. Beyond the great gate lay a vast assembly hall bifurcated into a dozen different sub-tunnels. According to Iron Hands records, the mountain had been almost entirely hollowed out.
The Automated Sentry-Troopers and Armored Wardens fanned out into the various side passages. The massive Destroyers, however, followed the primary central artery. At the end of this great hall, the records indicated, lay a gargantuan laser array once intended for ship-board mounting.
It was said that Ferrus Manus had crafted this weapon after witnessing the Eye of Vulkan, a relic forged by the Lord of Drakes. Its power, however, had proven excessively destructive, leading the Primarch to store it here.
For the modern Imperium, there was no such thing as "excessive" power. Whether facing the encroaching Tyranid hive fleets, Necron dynasties, or the Arks of Omen held by the hateful traitors of Chaos, the Imperium only ever found its armaments lacking. They never feared a surplus of lethality. This was why the Iron Hands were driven to unearth the technological legacies of Ferrus. They hungered for the Primarch's genius. Though Manus was dead, the fruits of his intellect could still empower his sons to serve the Throne.
As the machine vanguard vanished into the depths, the Iron Hands dispersed into two-man cells to follow. Only an Apothecary remained behind to tend to the battle-brother who had lost his leg. Despite the unexpected turn of events, the sight of the Iron Men's ability to summon orbital reinforcements at will gave them a grim confidence.
The Sapient Machine Automaton remaining in the hall opened a heavy container it had been carrying. It withdrew a shimmering, golden cube and brought it to the wounded Astartes.
A synthesized voice echoed through the hall:
"Repair sequence commencing. This may cause discomfort, though this is a consequence of your crude physiological integration. This one-time field-repair unit may optimize certain defects in your bionics. Should discomfort persist, we can restore those defects later."
The golden cube appeared to liquefy, flowing over the crippled Iron Hand. The golden fluid swirled across his power armor, emitting pulses of soft, radiant light. Golden lines began to weave themselves across the void where his left leg had been, knitting together a complete skeletal structure. Once the foundation was set, the gold continued to manifest, taking the form of the power armor's greaves.
As the light faded, both the Apothecary and the wounded warrior stood frozen in disbelief.
Mechanical regeneration?
Not only had the missing bionic limb been reconstructed, but the external power armor had been fully restored. The plating was pristine, as if it had just left the forge-altars, without a single scratch remaining. Even for an Apothecary, whose technical skill rivaled a Techmarine of any other Chapter, the sight was miraculous. The seamless integration between the new structure and the old armor was perfect; there was no trace of a seam.
The warrior immediately felt the "discomfort" the automaton had mentioned. Fully one-third of his body consisted of bionic replacements. Given the "crude" nature of those original bionics, the repair module had automatically corrected several design flaws during the reconstruction. He found his reaction times significantly sharper than before; the power output of his bionics had increased by nearly 20%.
The sudden surge of efficiency was, indeed, hard to adapt to.