Abyss-class Battleship

An Abyss-class Battleship was a part of a triumvirate of unique Imperial class Battleships of special configuration. The Furious Abyss, the first of its kind, was created and built in the Jovian shipyards of Thule which orbited the gas giant of Jupiter in the Sol System in the early 31st Millennium. Its sister ships, the Blessed Lady and the Trisagion were constructed at the same time in an undisclosed location. These vessels were constructed in secret during the latter years of the Great Crusade by the Renegade Dark Mechanicus faction loyal to Kelbor-Hal, the Fabricator-General of Mars' Mechanicum. These vessels were constructed for the Word Bearers Space Marine Legion, who were secretly ordered by the rebellious Warmaster Horus to bring their unfettered wrath down upon their hated rivals, the Ultramarines Legion. The Furious Abyss was to play an instrumental role in the Battle of Calth and the Traitor Legion's destructive campaign into the Realms of Ultramar.

The Furious Abyss
During the latter days of the Great Crusade, the Fabricator-General of Mars, Kelbor-Hal, had already thrown in his lot with the Traitor Warmaster Horus and committed to his cause. He had been tasked with the construction of a mighty vessel of unique design, an Abyss-class Battleship, built on a scale never before seen by Man. Kelbor-Hal had allowed the commissioning of vast quantities of material, menials and munitions in the construction of the mighty Battleship because it suited his purposes. Horus had unfettered Mars in its pursuit of the divine machine, countermanding the Emperor's restrictions on what technologies the Mechanicum could research and develop. For Kelbor-Hal the question of his allegiance and that of the Mechanicum was one of logic, and had required mere nanoseconds of computation.

The gargantuan ship, christened by the Word Bearers as the Furious Abyss, had been forged with such heavy armour that it could withstand even a concerted assault from a defence laser battery. Its blunt bullet prow, and the way its flanks splayed out to encompass the enormous midsection, spoke of strength and precision. Three massive crenellated decks extended from it like the sharpened prongs of a stygian trident. Twin banks of laser batteries gleamed in dull gunmetal down its broadsides. A single volley would have annihilated the loading bay and everyone in it. Cannon mounts sat idle on angular blocks of metal filled with viewpoints that hinted at the myriad chambers within. The rapacious bristle of the defensive turrets along the dorsal and ventral spines, and the dark indentations of the torpedo tubes, shimmered with violent intent. Spiked antenna towers punched outward from multitudinous sub-decks, interspersed with further weapon arrays and torpedo bays. The ship’s ribbed belly shimmered like oil and was replete with dozens of fighter hangars.

At the stern, the huge cowlings of the exhausts flared over the deep glow of the warming engines, primed to unleash enough thrust to force the warship away from Thule. Like chrome hexagons, the engine vents were so vast and terrible that to stare into their dormant hearts was to engulf all sense and reason in a fathomless darkened void. Finally, sheets of shielding peeled off the prow, revealing a massive figurehead: a book, wreathed in flame, wrought from gold and silver. Words of Lorgar's choosing were engraved on the pages in letters many metres high. It was the greatest and largest vessel ever forged, unique in every way and powerful beyond reckoning. This ship, this mighty ship, had been made for the Word Bearers, and in the Jovian shipyards its long-awaited construction had finally reached an end. This was to be a blow against the Emperor, a blow for Horus. None would know of the vessel’s existence until it was too late. Steps had been taken to ensure that remained the case. The launch from little known, and even less regarded, Thule was part of that deceit, but only part.

The Furious Abyss was to be manned by one thousand Astartes, a full Chapter split into ten companies, each a hundred strong. All heeded the Word of Lorgar. The Legionaries were resplendent in their new crimson-coloured Power Armour, sheaves of prayer parchment, scorched trails of vellum writ over with litanies of battle, and the bloodied pages ripped from sermons of retribution were affixed to their battle plate, openly declaring their allegiance to Chaos Undivided. They were led by Fleet-Captain Zadkiel, a devout and zealous Astartes and a deep believer in the Word of Lorgar. He was charged by the Dark Apostle Kor Phaeron to lead the assault upon the world of Macragge, where they would strike the first blow against the hated Imperium of Man. But ultimately, Zadkiel failed in achieving his objective when the Furious Abyss was boarded by a small ad hoc force of Loyalist Astartes who had learned of the Word Bearers' role in Horus' rebellion and who proceeded to sabotage the massive vessel and destroy it before its array of formidable weaponry could be brought to bear against the worlds of Ultramar.

Shadow Crusade
In the meantime, the Word Bearers' invasion of Ultramar proceeded to achieve a monumental victory at the Battle of Calth. The Ultramarines Legion was badly crippled by the Word Bearers' assault at Calth and no longer presented a viable threat to Horus' plan to drive on Terra. Erebus had managed to complete his blasphemous ritual on Calth's surface, which summoned the beginnings of the sorcerous Ruinstorm to the galaxy's Eastern Fringe -- a monstrous Warp Storm larger and more destructive than anything space-faring humanity had witnessed since the days of the Age of Strife. Simultaneously, with the Word Bearers' assault on Calth, Lorgar and the more reliable Word Bearers under his command launched a second offensive, a joint Shadow Crusade with his brother Angron and his World Eaters Legion into the rest of the Realm of Ultramar. They would go on to lay waste to the Five Hundred Worlds with reckless abandon, slaughtering twenty-six worlds in rapid succession. This was to ensure the success of the sorcerous Ruinstorm, which would ultimately split the void asunder, dividing the galaxy in two and rendering vast tracts of the Imperium impassable for centuries, effectively cutting Ultramar off from the rest of the Imperium.

Assault on Armatura
During one of their early campaigns, the joint Traitor fleet was to assault the War World of Armatura, a vitally important planet that fed the Ultramarines Legion with recruits and munitions. Its close-orbit played home to immense Imperial shipyards. Orbital bastions of linked gantries and docking maws drifted above the placid world. Above and beyond the shipyard was the first concentric ring of void defences. Here, weaponised satellites and fire platforms bristled with turrets, alongside independent landing decks for fighter craft in lockdown. Beyond those, the true defences began. These were literal castles in the sky: great fortress-stations with their own racks of fighters and entire battlements given over to plasma batteries, laser broadsides and ship-killing Lance arrays. In highest orbit, the outer sphere of satellites was a three-dimensional spread of solar panels, clockwork engines and slaved Servitor brains all connected to vast long-range weapons arrays. Amidst that outermost defence sphere waited the Evocati fleet. While the Legion mustered at Calth, the XIII Legion's War World could never be left undefended. The Evocati was comprised of several thousand Ultramarines drawn from a dozen Chapters of the Legion, awarded the highest honour of all: overseeing the operations of Armatura and the training of new recruits, commanding an Imperial fleet to rival any other.

It appeared that Lorgar's plans to assault Armatura were for naught, for to attack the War World the Word Bearers would need a vessel to rival anything humanity had ever wrought. The Word Bearers had possessed such a vessel once -- the Furious Abyss. But it had been destroyed days earlier, close to the same moment Kor Phaeron's expeditionary force had struck Calth. Its corpse was probably still a shadow in the skies of Macragge, a monument to the Word Bearers' failure. Lorgar had told Zadkiel he was foolish to attack Macragge, but the Fleet-Captain was so keen to bathe in glory, for all he ever heard were the whispers begging for revenge for the humilation of the Word Bearers on Khur. So the Aurelian had indulged him. But Lorgar had been underestimated, for he had planned for just such an eventuality. He had been planning the events that led up to the Horus Heresy for nearly half a Terran century. Lorgar's foresight became apparent when a vast trident of dark metal emerged from Warpspace near Armatura, a great warship whose shape was immediately familiar to the Word Bearers fleet approaching Armatura.

The starship that emerged into reality was a reflection of the slain colossus once called the Furious Abyss. A veritable city of monasteries and cathedrals rose from its back with the reverence of clawed hands sculpted to clutch at the stars. Where most Imperial Battleships were spears of crenellated intent and iron-ridged might, this was a fortress in space, borne on the back of a great trident. The central tine served as the vessel’s core: dense at the stern, encrusted with massive engines and tapering towards the prow, where it formed a pointed ram the size of lesser vessels. The trident’s adjacent tines formed smaller blade-wings, each one barnacled with laser broadsides and Macro-cannon batteries. If one were to clad the concept of spite in iron and set it sailing amongst the stars, it might approach the image of what burst back into the universe in that moment. It was, in every way, the Furious Abyss reborn. This mighty vessel was the Blessed Lady. This colossus was named for the Word Bearers' former Confessor, Cyrene Valantion, the Confessor of the Word, and the lone survivor of the destruction of the Perfect City of Monarchia at the hands of the Ultramarines on the world of Khur. The Blessed Lady easily eclipsed the Gloriana-class Battleships used as flagships by most of the other Space Marine Legions. But Lorgar's final secret was yet to be revealed. He had not had only two of these mighty vessels built in the Mechanicum shipyards orbiting Jupiter. As a second Warp-slice ripped across the stars near Armatura, another colossus was revealed. This was the Blessed-Lady's twin sister-ship, the Trisagion. The pair of Dreadnoughts rivaled even the Imperial Fists' Primarch Rogal Dorn's precious Phalanx in size and firepower. Lorgar had secretly had three of these mighty vessels built for the service of the Word Bearers.

The Blessed Lady and her twin sister, the Trisagion, made a mockery of Armatura's orbital arrays, dismantling one of the best-defended worlds in the Imperium with barrage after barrage from their howling, flashing weapon decks. The ships’ size and scale rendered all countermeasures obsolete. For the first hour, nothing could punch through their Void Shields. Nothing even managed to scrape their skin. It took the combined firepower of a battle-station, two orbital defence platforms and a suicidal ramming from an Imperial warship to finally penetrate the Blessed Lady's shields. She sailed on, oblivious to the thousands dying within one of the flaming monasteries on her back, for their agonies made no difference at all to a crew composed of half a million men and women, all singing the praises of Logar and the Chaos Gods. The Word Bearers mighty Batleships made a mockery of the Ultramarines' defences and helped crush the Evocati fleet and win the day at Armatura for the Traitors.

The fate of the Blessed Lady and the Trisagion following the campaign at Armatura is currently unknown in the fragmentary Imperial records of the Horus Heresy era.

Armament
An Abyss-class Battleship possessed a formidable array of weaponry, with hundreds of laser batteries that ran the length of both of its sides. It also possessed an experimental weapon: a plasma lance embedded in its prow, developed as a direct fire close-range weapon for ship-to-ship combat, able to fire at point-blank ranges. An ''Abyss' battleship could also deploy psionic mines when in transit in the Warp, to collapse stable warp routes when being followed by enemy vessels.