The Basilisk artillery batteries had been dug in behind breastworks of sandbags and scavenged plasteel. These cannons, echoing a primitive aesthetic reminiscent of ancient Terra's world wars, hammered away at the shattered enemy lines, shell by shell, under the relentless direction of Astra Militarum gunners.
Boom-boom-boom-boom…
The deafening cacophony threatened to burst eardrums. Cowering in temporary foxholes, the Guardsmen lay prone, eyes clenched shut as they weathered the storm under the dual pressure of their Commissars' inspiration and lethal threats. The filthy, upright rodent-xenos across the field were physically frail, possessing almost no armor, yet their bizarre weaponry was utterly catastrophic.
These mortals had watched with their own eyes as boarding parties of the Adeptus Astartes were either riddled into sieves by green-glowing projectiles or melted into slag by unnatural emerald flames.
The Skaven, however, were not merely taking punishment. High above, arcs of jagged green rock, the hue of Warpstone, streaked across the sky like falling stars.
When these projectiles impacted the Imperial lines, they shattered, erupting into clouds of virulent contagion. Those caught in the blast, or even those who merely grazed a fragment, were consumed by rapid-onset necrosis. Within seconds, their flesh rotted away, leaving behind nothing but blackened, withered corpses. Elsewhere, beams of emerald energy punched through the air with terrifying force, incinerating a dozen Leman Russ Battle Tanks in a single strobing discharge.
"By the... Throne... Emperor preserve us, what in the hell are those things?"
Trembling and muttering to himself, a lone Guardsman clutched his lasgun, his mind a frantic litany of prayer to the Golden Throne.
From a high vantage point, Astoren Korr surveyed the theater of war. He could see the Imperial bastions and the squalid positions of the xenos—crouched, fur-clad, loathsome creatures huddled behind scrap-heaps, firing volleys of green-tracered rounds from their rickety rifles.
Librarian divinations had confirmed the worst: those projectiles were infused with the horrific, corruptive essence of the Warp. Even the slightest contact could cause catastrophic biological collapse in mortals. These vermin had to be purged with the utmost prejudice.
Catching a fleeting tactical opening, Astoren Korr raised his hand, signaling the vox-casters to broadcast the order for a general advance.
This was the third assault. They had to reach the base of the Stygian Spires, regardless of the cost.
Receiving the command, the Commissars nodded, deactivated their vox-beads, and ignited their power swords. Their roars cut through the thunder of the guns: "Children of the God-Emperor! FORWARD!"
"YAAAARGHH!!"
The previously dormant Imperial lines erupted into a tidal wave of fury. Hundreds of Leman Russ tanks and a dozen Baneblades surged forward, flanked by squadrons of Sentinel walkers. Behind this iron vanguard, a sea of Imperial infantry charged toward the Skaven lines!
"They come-arrive! Moving-charging!"
A Skaven Warlord of Clan Blackback, a vassal of the mighty Clan Rictus, pulled his twitching eyes away from his Warp-telescope and shrieked.
His forces were no mere fodder. Among the Rictus hierarchy, Clan Blackback was a formidable power, boasting millions of claws and over a hundred thousand Stormvermin. Furthermore, Kratch had reinforced him with significant assets from Clan Skryre and Clan Moulder, and even the Plagueclaw Catapults of Clan Pestilens had been placed at his disposal.
"Must hold-stay! One day more! Yes-yes, just one day!" The Warlord rubbed his paws together nervously. "Get the Moulder monster-things ready! Tell the Packmasters—no idling! Skryre things to the front-front! None shall skitter-flee!"
The Stormvermin Guard scurried off to relay the commands.
On the front lines, Clanrats fired through trenches that resembled open sewers more than military fortifications. Their marksmanship was erratic at best, though a Skaven's aim is rarely intended for the enemy; if they couldn't accurately backstab a rival or a superior, they were fit only to be Slaves.
Suddenly, the mechanical thrum of power armor filled the air. These were the Skryre Acolytes, encased in full-body Warp-power suits, sealed tight as automata.
Flamethrowers and Ratling Guns, which in an age past required two Skaven to operate, were now wielded with ease thanks to the strength-enhancing suits. The only exception was the Poisoned Wind Mortar, which still required a dedicated bearer to carry the glass globes of toxic death.
Warp Lightning Cannons and Plagueclaw Catapults maintained a non-stop barrage. Though the catapults appeared archaic, Clan Pestilens insisted they were designed by the Great Horned Rat himself and refused to modernize. Curiously, through some esoteric Warp-resonance, the range of these "ancient" machines had extended to nearly thirty kilometers, a phenomenon the Plague Priests took as a divine sign of the Great Horned Rat's favor.
"Fire! FIRE-FIRE!"
First came the Poisoned Wind Mortars. These long-range indirect fire weapons were the first to respond after the heavy batteries. The charging Guardsmen looked up to see the lethal green spheres descending in high, graceful arcs.
Smash-crack!
The glass spheres shattered upon impact, releasing billowing clouds of emerald vapor.
"GAS!" a Commissar bellowed, snapping his respirator into place.
But the Poisoned Wind was no mundane chemical agent. It bypassed the filters of Imperial respirators; skin that touched the fine powder instantly began to fester and wither, turning into something resembling dry, dead wood.
"No—Emperor, NO!" The Commissar watched in horror as his own hand began to desiccate. He raised his power sword and hacked the limb off, but the exposure of the raw wound only accelerated the rot.
Waves of charging Guardsmen collapsed, screaming in agony before their bodies were reduced to desiccated husks.
"FOR THE EMPEROR!" Amidst the cacophony, a wing of some three hundred Seraphim from the Adeptus Sororitas streaked across the sky on jump packs. From the flanks, Astartes assault specialists from the Salamanders and Deathwatch followed suit, intending to bypass the meat-grinder and drop directly onto the Skaven gun-lines.
The Ratling Guns pivoted instantly. Their six-barreled assemblies spun into a blur, spitting a hailstorm of green tracer-rounds at the white exhaust trails in the sky.
Though some were brought down, many more slammed into the Skaven trenches.
Chainswords revved to a fever pitch. The Astartes—Salamanders, Deathwatch, and Iron Hands alike—moved with clinical brutality. Before these nine-foot-tall Primaris Space Marines, the Skaven looked like mere toys.
The slaughter was total. As the Astartes began their systematic eradication of the front line, the surrounding Clanrats broke. Panic took hold as the vermin lived up to their reputation, fleeing in a frantic, tail-tucked rout.
In an instant, the first Skaven defensive line collapsed. Masses of Astra Militarum infantry poured into the breach, bringing the Imperium one step closer to the Stygian Spires.
A Salamander lifted the mangled corpse of a Skaven, inspected it with a flash of contempt, and crushed it under his ceramite boot.
"Do not lower your guard, brothers. It is far from over."
Even as he spoke, the sky darkened once more with a fresh volley of Poisoned Wind Mortars.