Editing Siege of Terra (section)

==Battle at the Saturnine Wall==
[[File:Siege_of_Terra1.jpg|thumb|middle|500px|Just 0.000001% of 0.000001% of the Siege of Terra.]]

With the Lion's Gate spaceport lost, Dorn was now under tremendous pressure as he continued to coordinate the defense in the face of the unrelenting traitor assaults. Nearly all the Traitor Legions were committed to the battle at this point, with the Death Guard, Iron Warriors, Thousand Sons, Emperor's Children, and the Sons of Horus engaged in heavy fighting at the Anterior Barbican, a series of six fortresses protecting the Lion's Gate, while the World Eaters and the more Chaos corrupted Army regiments went on a rampage throughout the Palace's outer districts, tying down loyalist reinforcements in the Sprawl Magnifican. Additionally, the Lion's Gate spaceport allowed the Dark Mechanicum to begin landing Traitor Titans Legions inside the Palace walls, as well as armoured reinforcements for the Traitor Legions and Army. In response, Dorn could only muster his own legion, plus the Blood Angels and White Scars and their primarchs, along with what Army and Mechanicus units were stationed in the Inner Palace.

While taking a brief break in an abandoned garden, Dorn encountered Kyril Sindermann, who made an offhand comment about the Saturnine Wall trembling under the weight of the bombardment. From this, Dorn deduced that something was wrong with the defenses in that section and investigated. What he found was a potential catastrophe. The ceaseless bombardments from the traitor forces had caused the entire Imperial Palace and the tectonic plates on which it rested to shift by eight centimeters, opening a small but detectable fault line which had been previously sealed beneath the Saturnine Wall.

Certain that Perturabo would notice this fault and attempt to exploit it, Dorn began concocting a counterattack. Before laying out his plans, he called a council of war with Constantin Valdor and Malcador to explain to them his next move: he would have to start allowing parts of the Palace defenses to fall, as he simply no longer had the numbers or the materiel to hold everything. He identified four key parts of the defense that could not be allowed to fall to the enemy - the Colossi Gate, the Gorgon Bar, the Saturnine Wall, and the Eternity Wall spaceport - then chose the one he could most afford to lose based on his calculations, which was the spaceport. Though he would put on a show of defending it, Dorn knew that the port ultimately had to be sacrificed, even though it meant letting the traitor forces control both of the Palace's main spaceports. He assigned Sanguinius to hold the Gorgon Bar and Jaghatai Khan to hold the Colossi; he would personally oversee the defense of the Saturnine Wall and lay a trap in the hopes of bagging a significant enemy target, perhaps even Horus himself.

Perturabo had indeed spotted the weakness at the Saturnine Wall, though he had initially planned to use it only as a last-ditch ace in the hole, content to break the Anterior Barbican at either Colossi Gate or Gorgon Bar with what they had already landed, or wait for the World Eaters to inevitably overrun the Eternity Wall port and allow them to land reinforcements to fully overwhelm the two fortresses. Abaddon convinced him to instead make it a focal point of the attack through a combination of flattery and unsubtle goading, suggesting that Perturabo's victory over Dorn would be tainted if it was won with the help of the Neverborn. Though the Lord of Iron nearly caved his face in for it, Abaddon won the argument and immediately set out to assemble a spear-tip strike. Secretly, he was also hoping to win a "clean" victory without resorting to the use of daemons and sorcery, as he believed that using the Warp to win a war was beneath his dignity as an Astartes.

The battles for the Colossi and the Gorgon Bar escalated in scale and intensity. The defenders at the Colossi Gate were plagued by legions of flies that seemed to manifest from nowhere, forcing them to wear bulky protective equipment that lessened their effectiveness. Sanguinius was suffering under the weight of his psychic visions, which were coming with increasing frequency and intensity; nevertheless, he continued to fight on the front lines, knowing that his mere appearance was heartening the defenders and raising their morale. At one point he [[Awesome|singlehandedly killed a Warlord Titan]], then stared down its three accompanying Warhounds until they turned tail and fled. At the Colossi, Jaghatai and the White Scars led a few massed jetbike charges into the ranks of the Death Guard, destroying their siege engines, killing their Neverborn reinforcements, inflicting casualties, and generally delaying the XIV Legion's inexorable advance. The Adeptus Custodes also engaged the Death Guard, with Constantin Valdor himself taking the field. Their Emperor-forged nature proved especially potent against the Warp-corrupted Marines of the XIV and their daemonic allies. Ahriman and the Thousand Sons attempted to literally melt the Colossi bastion with sorcery, only to be driven back by three White Scars Stormseers who channeled the captured weather underneath the Palace's void shielding into an immense lightning storm.

At the Saturnine Wall, Dorn had devised a simple but cunning trap. Its cellars and tunnels had been fortified and transformed into a series of Zones Mortalis, and he had assembled a five-hundred-man strong force of veteran Astartes, broken into seven kill teams led by [[Sigismund]], [[Nathaniel Garro]], Endryd Haar of the World Eaters, [[Garviel Loken]], Bel Sepatus of the Blood Angels, Helig Gallor of the Death Guard, and [[Maximus Thane]] of the Imperial Fists. He had also enlisted the [[Technoarcheologist]] [[Arkhan Land]] to help him mend the fault line; Land devised a quick-setting form of rockcrete which could be pumped into the fault to seal it permanently. Dorn didn't know who would be leading the assault, but he was hoping for Horus himself. Once cut off and isolated inside the Palace walls, even the Warmaster would be ''relatively'' easy prey. On the other side, Abaddon was able to convince Fulgrim to lend him the entire Emperor's Children Legion for the assault on the Saturnine and wrangled three companies of the Sons of Horus to form the spear-tip. The III Legion would [[DISTRACTION CARNIFEX|attack from the front as a diversion]], using three [[Donjon Pattern Siege Engine|Donjon Pattern Siege Engines]] borrowed from the Dark Mechanicum, while Abaddon and his Astartes burrowed up from beneath with [[Tunneling_Transport_Vehicles#Termite|Termite assault drills]].
 
[[Just as planned|They walked straight into Dorn's trap]]. When the first Sons of Horus emerged from their assault drills, they were ambushed by Dorn's kill teams, who achieved total surprise. The assault force was ''DESTROYED IN DETAIL'', which is to say that of the hundreds of elite combatants committed to the attack (which included the famed Justaerin Terminators and Catulan Reavers of the 1st Company, all four members of the Mournival leading their respective companies, as well as two more veteran companies led by Tybalt Marr and Lev Goshen respectively) the number of survivors could literally be counted on one hand with fingers to spare. Garro decapitated Falkus Kibre of the Justaerin, while Loken killed Tybalt Marr, [[Horus Aximand]], and Tormageddon. Just as the loyalists were starting to relax, Abaddon and a hundred Justaerin Terminators teleported into their midst, triggering a giant brawl. Abaddon went on a killing spree, but eventually absorbed a series of crippling blows from Bel Sepatus and Endryd Haar. Though he managed to kill them both, he wound up pinned under Haar's corpse, with Garro poised to deliver the killing stroke. Luckily for Abaddon, [[Plot Armor|he was teleported to safety at the last moment]], as the Chaos Gods had already chosen him to be the new Warmaster after the death of Horus. Arkhan Land began pumping hundreds of thousands of liters of his rockcrete formula into the fault. Though he was briefly interrupted by Horus Aximand, the plan went off without a hitch, and the fault was permanently sealed. Some of the remaining Sons of Horus had yet to emerge from their assault drills and became trapped in the rockcrete as it set, ensuring that they would be entombed beneath the Palace forever. Barring any future statements to the contrary, it appears that literally the only survivor of this deflated, wilted bit of tactical flailing, once laughably referred to as a spear-thrust, was the very [[Abaddon|armless failure]] that advocated so strongly for it. [[Fail|Oops]].

Aboveground, Fulgrim had unleashed a full-scale assault against the Saturnine Wall, leading off with the Donjon siege engines, which had been modified with immense [[Sonic Weaponry|sonic weapons]] similar to those of the [[Kakophoni (Emperor's Children)|Kakophoni]]. The engines seriously disrupted the defense at first, but the Imperial Fists and Army garrison were able to rally and funnel the III Legion into a chokepoint. Fulgrim got into a duel with Sigismund atop the Wall. Though the Templar was able to land a few hits, Fulgrim's daemonically enhanced strength and speed gave him the upper hand. Before he could kill Sigismund, Dorn intervened and proceeded to pummel Fulgrim badly enough that the Phoenician threw a tantrum and took his legion and went home, abandoning the Siege entirely and costing Team Horus one of its most significant force multipliers. Fulgrim left fifty-six of his best warriors behind in an attempt to kill Dorn, but he and Sigismund were able to defeat them all, including [[Eidolon]] and Von Kalda. The assault wound up costing the Emperor's Children no less than eighteen thousand Astartes, along with all three of the irreplaceable siege engines.

This great victory had been purchased with an equally great loss: the fall of the Eternity Wall spaceport. Despite the garrison's best efforts to hold the port, they were faced with the Chaos-fueled rage of Angron and the World Eaters. Angron issued a demand for the port's defenders to surrender and was met with a concentrated artillery barrage that literally atomized him, though being a daemon prince, he didn't stay down for long. He and his legion immediately assaulted and seized the spaceport, killing everyone present. Many heroes of the Imperium died unheralded deaths at the Eternity Wall, including Knight-Commander Jenetia Krole of the Silent Sisterhood, Prefect Warden Tsutomu of the Adeptus Custodes, High Primary Solar General Saul Niborran, and Captain Camba Diaz of the Imperial Fists (who died holding the line in one of the greatest displays of manliness in the universe). A lone Guardsman named Olly Piers died there also, defending a banner of the Emperor Ascendant against Angron's relentless charge, thus [[Ollanius Pius|establishing the foundation for one of the Imperium's most enduring myths]] after a considerable amount of embellishment at his dying request. Ironically, Piers was a distant descendant of Ollanius Persson.

In the aftermath of these battles, Dorn and Sanguinius took stock of where they stood. The Gorgon Bar had held and would continue to hold for two precious weeks more by Sanguinius' estimate. The repulse at the Saturnine Wall had cost the Traitor Legions dearly. Three hundred of the XVI Legion's elite troops and eighteen thousand Emperor's Children were dead, with Fulgrim and the rest of the III Legion having quit the field. Jaghatai Khan, having held the Colossi, was now preparing to retake the Lion's Gate. Better yet, Sanguinius' prescience had granted him a vision from within the depths of Angron's tortured mind: [[Nuceria]] had been destroyed - not merely razed as Angron and Lorgar had done during the [[Battle of Calth|Shadow Crusade]], but obliterated by orbital bombardment. Dorn and Sanguinius both knew this could mean only one thing: Roboute Guilliman and Lion el'Jonson were on the way along with their legions.

Admiral Niora Su-Kassen, now in command of what remained of the loyalist naval assets in the Solar system, received indications of another fleet approaching from the outer edges of the system. She ordered the new arrivals to announce themselves, and was answered with a hail from [[Corswain]] of the Dark Angels: "We come to stand with Terra".