Several days later.
For the resistance fighters guarding the fortress, the recent days had been remarkably tranquil.
Perhaps the invaders calling themselves the "Imperium of Man" had indeed been stung by their previous failures. Several failed assaults might have forced their commanders to reconsider whether a military solution was truly viable here.
Perhaps they had already begun preparing for negotiations. The defenders believed they could leverage the fortress's resilience and the casualties they had inflicted on the Imperial forces to secure favorable terms for their surrender.
Sure enough, a few days later, the Imperium dispatched envoys, expressing a desire to resolve the world's compliance through negotiation. If possible, the Imperial government claimed it wouldn't mind granting the world significant autonomy.
Buoyed by their success in stalling the Imperial war machine, the defenders were in high spirits and held themselves with considerable arrogance, setting forth a series of demanding conditions. This turned the negotiations into something akin to haggling in a marketplace, with both sides engaging in fierce verbal sparring.
However, since negotiations had commenced, it signaled that the war was nearing its end. As the exchange of fire across the lines gradually died down, the defenders slowly lowered their guard, allowing a sense of complacency to take root.
The once-rigorous patrols along the battlements began to slacken. Except for the most essential watches, units were withdrawn to allow the highly stressed soldiers to relax.
It seemed that the conflict was settling into a diplomatic conclusion. Or so it appeared.
Iron Warriors Command Post.
"My Lord, why have you dispatched envoys to negotiate with those nameless rebels? They are posturing because of their recent record and have set conditions that could never pass muster on Terra!"
"Yet you allow them to continue their nonsense at the bargaining table! I do not understand!"
Perturabo was hunched over a command table, studying a stack of terrain maps and the structural sketches of the fortress produced by the Imperial Fists' scouts.
Forrix stood before him, asking the question with a look of confusion. Behind him, the other Iron Warrior officers were equally red-faced with indignation.
The attitude of the resistance representatives infuriated the officers tasked with managing the logistics. Because the defenders viewed themselves as the victors, they were exceptionally disrespectful to the Imperial officials—treatment the Iron Warriors found intolerable.
"Heh, so you all find the attitude of these rebels unacceptable?"
After studying the diagrams for a long while, Perturabo finally looked up. Seeing the angry faces of his sons, the Iron Tsar let out a soft, dry chuckle.
"Indeed, My Lord. Do you truly wish for a peaceful resolution? You said yourself that you would take this fortress in the shortest time possible!"
"Only give the order, and we are ready to lead our battle-brothers to lay down our lives for your plan!"
Forrix stepped forward, his voice ringing with passionate resolve as he pleaded for the chance to strike.
"It is a good thing that you still possess such sharp edges."
"However, I require a meticulously deployed plan to shatter their defenses instantly. To achieve that effect, I must deceive these resistors and cause them to drop their guard."
"Only then can I provide them with the ultimate surprise."
"Dorn was right. If I sent you into a headlong assault without a precise plan, it would be irresponsible—a crime. Though that stone's tongue is quite grating, he was correct in that regard."
Hearing Forrix's impassioned plea for battle, Perturabo smiled faintly and spoke in a tone intended to settle his men.
"So, My Lord... you have a concept? A way to breach their lines?"
The Iron Warriors exchanged looks of relief and anticipation. Forrix then asked the question with careful curiosity.
"Indeed, Forrix. I have formulated the plan."
"After analyzing the terrain and the sketches from the Seventh Legion, I have used my knowledge and intellect to construct a comprehensive strategy."
"First, I have already dispatched a number of combat engineers to tunnel beneath the foundations of the fortress. They are currently placing explosives at the very roots of the walls. Once the operation begins, these charges will detonate simultaneously."
"For the mission to succeed, the defenders must remain in a state of lethargy. They must believe that we are about to concede and that the victory is theirs. This is why I have had you persevere through these grueling negotiations and allowed them to set those irrational terms."
"This way, they become obsessed with the bargaining, convinced that if they simply hold firm, we will surrender. While they fight their battles at the negotiating table, our engineers are burying the seeds of their destruction beneath their feet."
Perturabo spoke with calm detachment as he broke down the layers of his strategy.
"I see. That is a brilliant maneuver, My Lord! So, we are to continue tolerating these arrogant representatives? We must continue to endure their pride and their ridiculous demands?"
Forrix nodded with profound respect as the logic of the situation became clear to him.
"Precisely. Tolerating their unreasonable demands also provides us with a justification when we eventually turn our backs on the table to resume the attack. After all, they demand things like the right to elect their own leaders and an exemption from the Imperial Tithe. No Primarch would ever agree to terms that insult the Emperor himself."
"By the time they realize the truth, it will be too late."
Perturabo nodded slightly.
"Simultaneously with the detonation, I will organize a creeping barrage of unprecedented scale. You will launch the first and final assault on this fortress under the cover of absolute fire superiority."
"According to my calculations, between these two waves of offense, the fortress will fall in less than seven Terran hours. The light of the Emperor shall shine over this entire world."
"And that estimate includes the possibility of urban combat after the breach. We will finish these resistors with the utmost speed."