The Iron Cage
On the world of Sebastus IV Perturabo and his Iron Warriors had set about building a mighty bastion called the 'Eternal Fortress'. This impenetrable citadel was both an act of defiance and an obscene act of mockery
Built out of grey stone and wrought iron was an exact replica of the Imperial Palace on Terra, every detail perfectly reproduced save that the milling crowds and defence militia were formed of mutants. Perturabo's intent was writ large for the galaxy to see, that he could succeed where Rogal Dorn failed, defend what the Praetorian of Terra could not.
Perturabo had sent a message to his brother: if he had been chosen to fortify the Imperial Palace the Emperor would still be animate. Rogal Dorn was incensed by this outrage; the Traitors had lost their war yet here they were flying their flag on an imperial world as if they had some right to be there.
Here was an opportunity to prove the worth of the old Legions, and crush the reforms sweeping the Imperium. With this victory Rogal would humiliate Guilliman and drive him back to his precious Ultramar in shame.
The Imperial Fists had suffered grievous casualties in the siege of Terra and the hard years of fighting since but Dorn was adamant. He still commanded twenty-one thousand Astartes, now second only to Guilliman's Legion in terms of numbers and he gathered them all for this one assault.
Rogal Dorn expected honourable battle but that was not Perturabo's agenda at all.
The Iron Warriors waited below the surface for the first shots of the Imperial Fists orbital barrage. As soon as it commenced they replied with a number of remote weapons silos located in the grounds of the replica Eternity Wall and Lions Gate spaceports. The VIIth reacted in a predictable manner by launching a full combat drop against the space ports. The objectives were swiftly secured and the loyalists began a full scale deployment, landing vast quantities of supplies and ordnance expecting a prolonged siege.
Their expectations would be cruelly shattered.
Once they were fully committed atomonic charges were detonated across the continent throwing millions of tons of debris into the stratosphere. Day turned to endless twilight and the Imperial Fists realised they were completely cut off from their fleet in orbit.
The detonation was the signal for the Iron Warriors' fleet to attack. The Traitors armada were no stronger than the Loyalists fleet but the Imperial Fists themselves were on the planet's surface. The ships crews tried to hold out, but they were assailed by Astartes boarding parties and forced to retreat. After a few hours the only targets being engaged on the planet were co-ordinates pre-planned by Perturabo.
Under fire from space, the VIIth Legion proceeded to advance on the Eternal Fortress on a four-company front. Perturabo watched from an observation tower and methodically began to destroy them.
For the Imperial Fists it was like walking through a reoccurring nightmare. The Eternal Fortress was a perfect replica of the Imperial Palace, as familiar to them as their own amour. Every detail was exact, every gun and gate in the exact alignment as it had been in the Siege of Terra. Most of the Astartes had been present for the culmination of the Heresy and were horrified to be reliving it, except now they were the attackers and the Traitors the defenders.
Across the length and breadth of the Eternal Fortress battle was joined, noble golden warriors battling mutants and Traitors at every corner, corridor and cross roads.
Across the ramparts of the false Primus gate the Imperial Fists infantry stormed against thousands of mutants who sang songs of dead Olympia. They were supported by the dregs of the IVth legion, half-dead cybernetic by-blows, gun-servitors, disgraced squads and Contemptor-Cortus dreadnoughts. The battle raged for a day and a night before the Loyalists broke through the Gate only to discover that while they were distracted Possessed Marines had infiltrated their forward bases and detonated vast quantities of ammunition reserves.
In the faux Temple Square the Iron Warriors launched a mechanised counter attack. Rogal Dorn sent an assault company to meet them but when the two foes collided the Imperial Fists discovered the few Traitors present were but a cover for Rhinos overloaded with explosives. The force of the blast was visible across the length of the Eternal Fortress slaying everyone present and levelling a district the Fists had spent eleven hours securing.
At the fake Annapurna gate a kill-Team of Fists' sappers were horrified to find that Perturabo had anticipated their route and pre-positioned a vast series of mutant latrines. These middens were mixed with a vile daemonic acid that ate through armour seals and rebreathers leaving one hundred Astartes to drown in a lake of reeking sewage.
Confronted by the great weight of the ersatz Saturine Gate the VIIth Legion unleashed a column of super-heavy Falchions, Cerberus destroyers and Sicarian Venators. Their combined firepower brought the gate down only to find Perturabo had already positioned his three Ordinatus Diamat behind it. The first salvo of the Continental Siege guns annihilated half the forces besieging the gate. Stoic as ever the Imperial Fists' return fire destroyed one siege engine but the second and third barrages left no survivors and also no stone standing upon another for a straight mile.
In the precincts of the City of Sight the Imperial Fists waded through an army of mutants slaughtering their way forwards inch by blood soaked inch to reach the Conduit. Yet the moment the first Loyalist set foot upon its steps Perturabo detonated seismic charges in its foundations and brought the entire edifice down upon their heads.
Rogal Dorn was the greatest master of siege in the Imperium but he was operating from a flawed assumption. Every fortification is limited by the need to protect something but Pertuarbo cared about absolutely nothing but humiliating his foes. He deliberately allowed whole districts of the Eternal Fortress to fall to the Loyalists advance only to bring them down on their heads. He sacrificed hundreds of his own sons to bait traps and snares but did not care as long as the butchers' bill was on his side.
By the sixth day of the battle each Imperial Fist fought virtually alone, Dorn's troops were reduced to burrowing into the dirt and piling up the dead bodies of their brethren for cover. They had not even reached the Investiary and already their casualties were on the wrong side of horrific.
Still Perturabo remained patient, he allowed Dorn to rampage beneath the walls calling his name and demanding personal combat. Perturabo had no intention of doing something so stupid; he knew that the sight of their Primarch's impotence would demoralise the Imperial Fists more than he ever could.
Imperial Fists had burrowed into the killing zone and were unable to escape, although his captains called for a breakout Rogal Dorn would not give the order. He refused to concede that victory was beyond them, that Perturabo had outmanoeuvred him.
He would die before admitting that the doctrines that had served him so well throughout the Crusade and the Heresy had been found wanting. Above all he could not admit that he had made a mistake: that Guilliman had been right and he wrong.
Unable to abandon their Primarch the Imperial Fists prepared to die with him.