Compared to the flank embroiled in the pursuit of the traitors, the mechanical cohorts entering through the other metal access shafts encountered no further resistance.
In the nearly twenty thousand years that had bled away, the mechanical garrison stationed here had dwindled to fewer than a hundred functional units. Due to the encroaching Chaos forces, these remaining guardians had been concentrated in a single sector to stem the tide. Consequently, the other mechanical columns advanced at a pace that far outstripped the Black Legion, who were still mired in skirmishes with the local automata.
As they descended nearly two thousand kilometers into the planet's crust, a colossal cavernous structure opened before Axion's sensory arrays. By synthesizing data from multiple scanning units, the internal architecture of the world was fully laid bare.
This planet, twelve thousand kilometers in diameter, had been pierced by six gargantuan metal shafts plunging two thousand kilometers deep. At that depth, the shafts opened into a planetary-scale void, a ring-cavity encompassing the entire world. The interior had been hollowed out, leaving a massive, hundred-kilometer-high space filled with countless gargantuan tanks and cyclopean alloy structures arranged in a precise, geometric grid.
Deeper still lay the planet's churning, incandescent core. It was evident that the entire world had undergone profound geomechanical restructuring; it was essentially a hollow shell. Here, the gravitational environment sat at the equilibrium point between the outer crust and the molten core, creating a sensation of weightlessness akin to deep space.
The pervasive green, high-energy mist originated from a massive leak within a cluster of interconnected storage vats. Though the potent atmospheric circulation system remained functional, its control logic had clearly suffered catastrophic failure. The mist was being endlessly filtered, collected, compressed, and liquefied, only to leak back into the void in a futile, recursive loop.
Upon these vats, Axion identified a highly specific sigil and a string of script:
Ultra-High Pressure Liquid Eridium Gas Tank.
Axion's database lacked exhaustive technical specifications for this energy-mineral, marking it only as a "Critically Vital Federation Asset." However, the devices powered by this mineral represented another tier of top-level Federation technology:
Chronological Controllers.
Information regarding the manufacture and technical principles of all spatio-temporal apparatuses was absent from Axion's archives. This was not a technology intended for the Iron Men to wield or master. During the era of the Federation, all fruits of this research were subjected to the most draconian oversight.
Such devices had only seen large-scale deployment during the catastrophic wars against the ancient Aeldari Empire. According to the records, these apparatuses came in various specifications capable of triggering temporal regressions of varying magnitudes. The smallest models generated a chronal field barely large enough to encompass a palm-sized object, while the largest could shroud an entire star system.
This perilous technology was capable of inducing horrific temporal paradoxes. Because the cognitive processes and logic-execution of the Iron Men differed so radically from their human creators, this technology and its associated data were strictly regulated.
The Federation had once used these tools to annihilate countless Aeldari hosts. Upon an Aeldari raid, the Federation would dispatch massive mechanical fleets to the periphery of the devastated system and initiate a total systemic temporal regression. Reverting the system to a point before the attack, the Federation would then utilize their absolute numerical superiority to intercept and exterminate the Aeldari forces.
Due to the resulting temporal paradox, the Aeldari forces in other regions of the same timeline would simply vanish into non-existence.
After the discovery of the Federation's mastery over chronotechnology, the Aeldari ceased all engagements without first consulting their farseers. If a prophecy indicated the possibility of a temporal regression, the Aeldari would abort the operation or shift their theater of war entirely.
In small-scale skirmishes, the Iron Men would reclaim their wreckage while the Aeldari absorbed their losses. In large-scale wars, the Aeldari were simply rewound and erased. To avoid such existential depletion, the Aeldari were forced to use their foresight to cancel major offensives or alter their strategic objectives.
The war between the Aeldari and the Federation could yield no decisive outcome; the Federation did not fear the attrition of small-scale conflict, and the Aeldari could not risk the erasure of large-scale ones. Furthermore, frequent, massive-scale temporal regressions threatened to unravel the physical universe itself, a mutual annihilation the Aeldari were unwilling to embrace. This was the direct catalyst that eventually led the Aeldari to sue for peace with the Federation.
The Aeldari had more than once mocked humanity as "infants waving thermal weapons without understanding the danger," but their derision did nothing to change the ultimate reality of the stalemate.
…
Axion had never imagined that this planet served as a repository for such a vital Federation asset.
To accelerate the exploration, swarms of Heavy Combat Drones were launched from orbit. These drones skimmed centimeters away from the alloy walls of the vertical shafts, hurtling toward the subterranean cavity with terrifying velocity. Their speed far exceeded that of the ground units, and Axion soon made an even more staggering discovery.
Within the planet lay a gargantuan, integrated starport. The massive metal shafts had been designed as the primary ingress and egress points for this shipyard.
Moored within this internal port were three ancient vessels of varying classes. The smallest was less than 2 kilometers long and 1.5 kilometers wide, while the largest approached nearly 30 kilometers in length.
Though Axion did not possess the construction schematics for these specific hulls, he found their identification codes within the Unified Combat Sequence Protocols:
Regression-class Vessels.
This was a specialized chronal-control task force from the Federation era. These ships were equipped with powerful Temporal Distortion Field Generators. These generators could project a specialized field over a designated zone, altering the spatio-temporal fabric within the field to achieve a localized "Time Regression."
Furthermore, these vessels were outfitted with a highly specialized rigid shielding system, the structural integrity of which was nearly triple that of the shields mounted on standard Iron Man Command Flagships.
Externally, these ships were unremarkable, sharing a silhouette similar to conventional Iron Man Strike Cruisers or Command Ships. They even mounted weapon systems that appeared standard. In practice, however, they were worlds apart.
Their Spatio-Temporal Distortion Cannons fired beams indistinguishable from standard plasma, perfectly concealing the chronal attack within a sheath of plasma discharge. This terrifying weapon induced temporal dysynchrony in the target area. A single entity caught in the blast could find different sections of its structure existing simultaneously in the past, the present, and an accelerated future.
If a ship were struck, one-third of its hull might be reverted to its position one minute prior; another third would remain in the present, while the final third would be catapulted one minute into the future. The sudden, violent spatial dislocation would instantly tear the vessel into three segments, appearing in three different locations simultaneously.
To maintain their disguise, these ships were also outfitted with conventional plasma turrets, heavy laser emitters, and long-range railguns. The logic was simple: embedded within a fleet, no observer would notice anything peculiar about these seemingly mundane vessels.
Yet, the value of these ships was astronomical. Based on the radius of the temporal fields they could project, a single vessel was worth an entire fleet. Even a Titan-class ship paled in comparison to the strategic worth of a large-scale Regression-class vessel.
For as long as a Regression-class ship remained operational, the Iron Man legions were, in a very literal sense, infinite.