As the radiance of the system's primary star faded, night descended upon the planet. Through the atmosphere, one could occasionally glimpse the bio-fleets of the Tyranids locked in a relentless exchange of fire with the Imperial Navy in high orbit. Whenever a target entered an optimal firing solution, the massive planetary defense batteries planet-side would roar to life.
The only entity that never remained idle was the Apocalypse-class Titan stationed within the defensive perimeter. Regardless of the planet's rotation, the Titan, capable of seeking firing angles with near-total freedom, surprised the Tyranid bio-ships every few minutes with a devastating long-range volley.
Along the reinforced trench lines, the frontline troops began a slow withdrawal. Sapient Machine Automatons moved forward to construct a series of energy transmission pylons. Without the Pectaro providing direct power support, even the Iron Men units could not sustain continuous combat. Splitting their forces meant a lack of reserves, forcing these tireless harvesters of death to halt and recharge. A significant portion of the logistics brought by each squad consisted of these massive "recharging stations."
Aside from the Apocalypse-class Titan and the Executor Heavy Tanks, which possessed independent power cores, the rest of the mechanical host required periodic replenishment. Circles of Armored Wardens formed a protective ring around the energy pylons while Automated Sentry-Troopers cycled back in batches to refuel their cells. The construction of fixed fortifications served not only to hold the line but to provide the necessary window for the machines to regain their lethality.
However, the sole remaining Imperial sector of the front suddenly became precarious. Prolonged combat had depleted the soldiers' ammunition; exhausted and hollow-eyed, the men of the Astra Militarum were barely able to chamber shells. Even the Adeptus Astartes found their power swords swinging with waning vigor. Chainswords had long since ground to a halt, and the disruption fields of the power weapons had flickered out.
The sea of chitinous horrors covering the hills seemed to fixate on this specific gap, surging toward the center in a frantic tide. Meanwhile, the mechanical units nearby, waiting for their recharge cycle, only occasionally opened fire to cull any xenos that wandered away from the Imperial line.
The sudden emergence of Mawlocs and Trygons added to the crushing pressure. These tunnel-beasts would burst through the earth, creating direct conduits into the trenches or even the rear lines. Swarms of Rippers and Termagants poured through these breaches. The casualty rate among the Imperial Guard skyrocketed, the mortal defenders dying in the mud only to be consumed.
The subterranean assaults did more than just break the morale of the overstretched ground forces; they provided the Hive Mind with a bounty of biomass. The corpses of the fallen were swiftly dragged into the dark by a carpet of Rippers, forcing the Astartes to divert their attention to sealing these sudden earthen maws.
On the adjacent mechanical sector, however, the Tyranids launched no such subterranean raids. It was clear that the cold, unyielding metal of the machines did not suit their appetite.
Whirr—!
The sharp whistle of displaced air shrieked from the flank. The missile pods of an Executor Heavy Tank unleashed a saturation strike. The missiles streaked into the Imperial sector, precisely finding the openings of every tunnel dug by the burrowing beasts. Dull thuds of subterranean detonations followed, causing vast sections of the earth to collapse.
Simultaneously, precise volleys erupted along the perimeter of the Imperial defense. Squads of Automated Sentry-Troopers cut off the breaches from both sides, while the Sapient Machine Automatons moved with blurring speed to construct fortifications and outposts, shoring up the crumbling Imperial line.
A few lingering Termagants and Rippers still scurried through the temporary trenches, hunting panicked mortal soldiers. A full company of Deathwatch moved across the four-hundred-meter wide and two-hundred-meter deep zone, acting as a fire brigade to quench the remaining resistance.
Ever since the Iron Men had cauterized the influx of the swarm, Lofus's eyes had been fixed on the industrious Sapient Machine Automatons. While he hunted the straggling xenos, he carefully observed the automatons and sentry units. When a group of Termagants lunged at an automaton that was currently welding scrap metal into defensive plating, what happened next shattered Lofus's preconceived notions of "servitors."
The Sapient Machine Automaton's simulated mechanical hand gripped a violently bent metal plate and swung it with immense force, pulping the nearest gaunt instantly. The other xenos were caught by auxiliary limbs extending from the machine's back, pinned effortlessly, and then systematically dismantled by laser cutters and welding torches.
The reaction speed the unit displayed was nothing like the sluggish, lobotomized servitors of the Imperium. Its movements were, in fact, scarcely slower than those of an Astartes.
Having neutralized the threat, the automaton simply turned back to its task. It efficiently completed a small defensive firing nest made of composite metal plates and moved on. An Automated Sentry-Trooper stepped into the position almost immediately, beginning to suppress any xenos within its visual range.
Watching this, the "Iron Hand" soul within Lofus burned with a fierce intensity. Compared to the simply designed sentry units, these multi-functional automatons fascinated him. The design was... perfect. If such technology could be integrated into his Chapter, they would serve the Emperor with even greater efficiency.
However, after muttering a quiet praise to the Omnissiah, Lofus abandoned the dangerous thought of "liberating" a friendly automaton. After a cold calculation, he realized that he might, just possibly, actually lose a fight against that "servitor."
He never suspected that because of his whispered praise to the Omnissiah, Axion had already categorized the entire Iron Hands Chapter as having the same ideological standing as the Adeptus Mechanicus.
Axion, monitoring the battlefield through his multi-threaded consciousness, diverted a small process to replay the combat data of this specific Iron Hand. He noted that the Astartes was staring at his units with the same fixated gaze as a Tech-Priest; perhaps more time had been spent looking at the machines than at the Tyranids. Information on the Iron Hands Chapter was quickly retrieved, marking them as the Space Marine equivalent of the Cult Mechanicus.
Though they weren't as erratic as the Tech-Priests, they were clearly cut from the same cloth. After scanning Lofus's frame, Axion concluded that a being with over fifty percent mechanical replacement was hardly a "normal" human. In a standard Chapter, such injuries would lead to internment in a Dreadnought; in the Iron Hands, these mutilations were largely self-inflicted. Like the Mechanicum of old, they viewed cybernetic enhancement as the ultimate pursuit.
As an artificial intelligence, Axion truly could not comprehend why these biological entities so desperately wished to become machines.
Once the defensive line was fully restored, Axion's voice echoed over the Imperial positions.
"My thanks to our allies for their valiant efforts. I shall now take command of the line. Please return to the rear to refit and recuperate."
The message was clear. Under the direction of the Angels of death, the Imperial troops began recovering their dead for transport to the rear. The Astartes gathered for a brief moment of respite. After a day of high-intensity combat, the mortal regiments were paralyzed; the constant cycle of firing and reloading had drained their spirits and bodies. Against the swarm, aiming was an afterthought, unending volleys had simply reduced the xenos to clouds of chitinous shrapnel.
As the Astartes discussed the engagement, they finally understood why the combat reports had claimed a staggering casualty ratio of one to three thousand.
Axion, meanwhile, directed the Eight-Legs and automatons to clear the xenos carcasses. White phosphorus munitions were deployed in mass, their flames illuminating the battlefield as tens of millions of Tyranid corpses were piled high and incinerated.
This scene played out across every planet receiving support. Slaughter by day; recharge and incineration by night. As the flames consumed the biomass, a presence within the Warp grew increasingly furious.