As the mission briefings concluded, squads of Deathwatch Veterans departed the staging grounds, deploying in the wake of the Iron Automata who had already punched a corridor tens of kilometers deep into enemy territory.
Behind them trailed the remnants of the Astra Militarum regiments, shattered remnants only recently rallied and integrated, alongside a negligible force of Planetary Defence Forces. Most of the world had already fallen to the Great Devourer; all that remained were two massive mountain fortresses and the colossal macro-cannon batteries they were sworn to protect.
The warriors watched in grim fascination as the iron frontline swept across the terrain like a titan's broom, scouring away the swarms that had nearly overrun the spaceport. Where the Tyranids had been on the verge of a breakthrough, they were now being hurled back for kilometers.
The ground was left as a hellscape of charred earth and mountain-high piles of xenos viscera.
The sheer, cold efficiency of the slaughter gave even the Adeptus Astartes pause. Proceeding with tactical caution, the Deathwatch kill-teams followed the wake of the machines, vox-casting observations and scrutinizing the battlefield.
Lofus's kill-team consisted of five battle-brothers. Aside from the Black Shield, Kan, there were two scions of the Imperial Fists, Augustus and Marcus. They were veterans who had shared the fires of previous campaigns; in the desperate ad-hoc formations of the Deathwatch, one naturally sought the steel-clad brotherhood of those already proven in blood.
In their formation, Augustus and Marcus took the vanguard. Lofus provided heavy fire support, while Kan, the Black Shield, coordinated suppression strikes. Thorne held the flank, serving as the unit's eyes and providing fluid tactical assistance. The sons of Dorn were masters of the vanguard; time and again, they were seen anchoring the line with their storm shields, interposing their ceramite bulk between the enemy and their brothers.
Compared to the mortal soldiers, the Astartes moved with a predatory proactivity.
Due to the dispersal of his forces, Axion did not push the line at maximum velocity. It was a calculated necessity: he had to keep attrition within projected margins and allow time for field repairs. The Deathwatch, trailing the main advance, soon identified the pattern.
Whenever a section of the mechanized line sustained critical damage, the advance would momentarily halt. Strange logistical constructs would rumble forward from the rear, dragging crates of spare parts and servitor units. Repairs and chassis replacements were conducted on-site, an operation lasting a mere fifteen minutes, yet it created a distinct, if brief, vacuum in the firing line.
It was only during these interludes that the Deathwatch found a purpose, picking off the stray organisms that managed to breach the temporary gap.
But for the Angels of Death, such fleeting engagements were insufficient. Restless and fueled by a righteous need to purge, the battle-brothers began engaging targets at long range. With the mechanical vanguard holding the front, the rear offered a stable platform for heavy ordnance.
Bolter shells, plasma bursts, and the occasional melta beam streaked into the fray, weaving through the shimmering paths of the Iron Automata's neutron beams. Yet, this unsolicited fire support soon began to destabilize the meticulously calculated firing lanes.
When the Astra Militarum joined the fray, the situation worsened. It wasn't long before the Peltast Sniper Automata at the rear ceased fire entirely.
A massive Erratana-class Armored Warden positioned at the center of the line swiveled its torso. For the first time, it issued a direct command to the Astartes and Guardsmen who were firing with such abandon.
A heavy, synthesized mechanical voice boomed across the vox-channels, echoing over the roar of battle. Simultaneously, a massive holographic tactical map flickered into existence before the Imperial commanders. It was a comprehensive display of the battlefield surrounding the two bases, every combat unit rendered in sharp detail. Certain sectors began to pulse with a high-intensity highlight.
"VACATING BATTLEFIELD SECTORS A4 THROUGH A6. TOTAL FRONTAGE: FOUR HUNDRED METERS. SECTOR ASSIGNED TO IMPERIAL FORCES. MAINTAIN ADVANCE VELOCITY IN SYNCHRONIZATION WITH THIS UNIT."
While Axion did not disregard his allies, their erratic bombardment and overlapping fields of fire represented a catastrophic waste of tactical efficiency. Though the Deathwatch possessed far superior accuracy compared to the Guardsmen, their shots frequently caused the forward Sentry-Troopers to register "target neutralized" mid-calculation, wasting pre-loaded firing solutions.
No matter how rapid the cogitation, the automata could not fully compensate for the unpredictable variables of unlinked allies. When the Astra Militarum arrived, the thunder of Basilisks and Leman Russ battle tanks only added to the redundancy. Firepower was being clumped rather than spread; kill-zones overlapped needlessly.
To Axion's logic-driven mind, such inefficiency was intolerable. However, he lacked the authority to command the "flesh-soldiers," and he knew mortal infantry could never sustain his required rate of output. The Imperium's weaponry was tragically primitive, lacking automation, requiring manual loading, and tethered to fragile supply lines. High-intensity combat would see these mortals collapse from exhaustion in short order.
To preserve the morale of the Imperial troops while purging the inefficiency, Axion simply yielded a segment of the line. It gave the Imperial forces a dedicated theater for their fury without clogging the Cogitator-arrays of his own units.
Under the direction of the Deathwatch, the dispersed Imperial regiments quickly coalesced, moving to occupy the newly vacated four-hundred-meter front.
Watching their allies advance from the rear had filled the demi-gods of the Astartes with a simmering frustration. They were the Emperor's chosen; their pride did not take kindly to being overshadowed by soulless husks of iron. They did not believe themselves inferior to these "iron dolls."
As the Imperial forces dug in, the Automated Sentry-Troopers ahead of them stepped aside with machine precision, ceding the sector.
The transition was instantaneous. A tidal wave of combat pressure slammed into the Angels of Death and their mortal charges.
Across that narrow four-hundred-meter strip, hundreds of thousands of Tyranids surged in undulating carpet-layers of chitin and claw. Every Basilisk shell sent thousands of xenos screaming into the sky in bursts of ichor. Leman Russ cannons roared, and sponson-mounted heavy bolters chewed through the swarms, while the disciplined volleys of lasgun fire from the infantry lines created a shimmering wall of death.
The Astartes threw themselves into the breach, their bolters barking in rhythmic execution, slaying any creature that dared draw near the line.
As the Imperial forces took the brunt of the assault in their sector, Axion halted the general advance. Following the logic of the terrain, he issued the command to fortify.
Automata that had landed with the heavy carriers moved to the front. At a speed that left the veteran Guardsmen speechless, they began scavenging battlefield debris, welding and riveting defensive works directly onto the scorched earth. A massive, contiguous defensive perimeter materialized in minutes.
With the line anchored by reinforced bunkers, the Tyranid Hive Mind sensed the sudden shift in resistance and adjusted its synapse-flow.
The sector held by the Imperial forces, lacking the cold, overlapping perfection of the machine-grid, immediately became the primary focus of the swarm.
Against the same tide of horror, the Iron Automata could project fire to within half a meter of their own forward Sentry-Troopers with surgical precision. Every shot was a kill; every cycle maximized lethality, thinning the swarm by eighty percent before a single claw reached the line.
The Imperial forces, even under the masterful direction of the Deathwatch, could not replicate such terrifying harmony.
As the hours ground on, the inevitable toll of biology began to show. The mortal soldiers, just as Axion had predicted, grew weary. Shell loading slowed; las-cells grew hot and volatile; fatigue dulled the eyes of the riflemen.
Even the Astartes began to feel the heavy weight of the endless slaughter. In a matter of hours, several battle-brothers had already discarded two or three overheated and jammed bolters for fresh ones.
Despite their gene-enhanced physiology and implanted organs, if the battle continued at this relentless tempo, these Space Marines risked becoming the first of the Emperor's Angels to simply drop dead from sheer exhaustion.