In the absence of overwhelming military strength, holding a fortress without utilizing the surrounding terrain is a poor strategy. This relinquishes any tactical advantage outside its walls, leaving defenders vulnerable to enemy fire and concentrated assaults.
Thus, upon learning of the imminent formation of a Warp rift, the expeditionary corps, recently bloodied from battle, immediately began to prepare their defensive lines.
The constant warfare had not dulled the spirits of the Emperor's servants. Even the mortal Astra Militarum were elite forces, rigorously selected and disciplined.
The disparity in size between the Withered Legion of Nurgle and the Expeditionary Corps meant the soldiers had conserved much of their strength for the upcoming battle.
Inside the Iron Fortress, Primarch Dukel radiated an almost tangible zeal, his expression so fervent one might think he intended to charge headlong into the Warp portal itself.
"What?! You want me to stay back and defend the last line of defense?!"
The communication from the Librarius caught him off guard.
"Yes, my lord. After extensive analysis, we calculate a 92.46% likelihood that the target of this Chaos incursion is you specifically," the Chief Librarian explained.
This group of highly trained psykers—typically aloof and eccentric—insisted with uncharacteristic fervor. They argued that Chaos undoubtedly had prepared traps, cursed weapons, and conspiracies aimed at the Primarch. Deploying him prematurely risked catastrophic consequences. Only after significant attrition to the enemy forces should the Primarch take to the field.
Dukel reluctantly acquiesced.
Even a Primarch must temper their desire for glory with responsibility to their comrades.
With his agreement, the Librarius exhaled in collective relief, transmitting real-time surveillance footage of the enemy advance.
The feed revealed a grotesque parade of Nurgle's legions, their twisted forms radiating obscene joy.
Nurglings competed in spitting contests, rotting Plaguebearers leaped clumsily, and imps frolicked amid the filth, rolling in excrement. Bored daemons yanked out their own entrails, using them for macabre games of tug-of-war.
Amid this chaos, the massive Great Unclean One, Lymphas, lumbered forward. His bloated form jiggled with each step, a perpetual grin plastered across his puss-ridden face. A viscous fluid splattered him, but he casually wiped it away, appearing delighted by the spectacle of his "children" thriving.
Around them, the land itself seemed to revel in corruption. Maggots and worms wriggled in jubilation, pus-laden vegetation sprouted unnaturally, and the stench of decay permeated the air.
Suddenly, Lymphas paused, raising his grotesque visage to the heavens. His gaze seemed to pierce the void, locking onto Dukel's through the surveillance feed.
Before anyone could react, pustules erupted on the ship's sensor arrays, severing the connection.
"The Withered Legion," muttered a Librarian grimly. "And Lymphas himself has come."
Among Nurgle's daemonic champions, Lymphas was a being of immense power, capable of turning the tide of war through sheer corruption. His legion was vast, capable of splitting into three fully independent armies.
Already, hundreds of thousands of daemons had emerged, with reinforcements pouring through the Warp rift.
The Outer Defense Line of the Iron Fortress
"For the Throne! For humanity!"
The defenders opened fire. Ultramarines and Astra Militarum formed tight tactical units, supported by Dreadnoughts, Knight Titans, and War Dog Titans unleashing devastating volleys.
Above, aerial units rained melta bombs and incendiaries, their payloads scouring swathes of the corrupted horde.
The sheer volume of enemies meant even poorly aimed shots found targets among the daemons.
"The false Emperor's followers are as lively as ever," Lymphas remarked, chuckling. The relentless bombardment barely fazed his mountainous frame.
He licked the viscous slime on his face, savoring its rancid flavor.
"Children, let's not disappoint them!" he bellowed. "Gift them Father's blessings. Pour forth your love—through every mouth, every wound, every breath!"
His words ignited the daemons into frenzied action. They surged forward, vying for his approval, their grotesque forms clambering over one another to attack the defenders.
Imperial forces answered with unrelenting fury, bolstered by fervent exhortations.
"Hold the line, warriors!"
"Behind us are our wounded comrades, innocent civilians, and the great Primarch himself. Stand firm for the Emperor!"
Artillery roared, and the ground churned under the combined onslaught of explosives and Warp-tainted sludge. Pre-laid traps detonated in succession, obliterating the vanguard of Nurgle's forces. Precision sniper fire felled towering plague apostles, their bloated forms collapsing in showers of ichor.
Yet the cost was heavy.
As daemonic projectiles splattered against Imperial ranks, foul contagions spread through the defenders. Despite their fortifications, the Imperium's forces struggled under the endless tide.
Lymphas strode confidently through the carnage, his grotesque form smashing aside obstacles. Each swing of his massive plague-flail unleashed a wave of Warp energy, reanimating fallen soldiers as putrid zombies.
The undead surged forward, fearless and toxic, their poisoned breaths sowing chaos among the defenders.
The Iron Fortress's perimeter faltered, its defenders forced to retreat step by step.
"Where is your Primarch? I heard he was revived!" Lymphas jeered, his booming laughter carrying over the battlefield. "Has he fled already?"
The taunt hung in the air, unanswered, as the battle raged on.