|Location||Ork Empire of Octarius|
|Orks||Hive Fleet Leviathan|
| Overfiend of Octarius
By the end of the 41st Millennium, the Imperium was beset by the third and mightiest Tyranid Hive Fleet, Leviathan. As the swarm rampaged throughout the southern plain of the galaxy, Inquisitor Kryptman desperately looked for an answer to the Tyranid threat. Looking to the Ork Empire of Octarius, Kryptman devised a plan to utilize mankind's old foe against the invading Tyranids and, in the best case scenario, kill two birds with one stone.
Kryptman led several specially equipped Deathwatch teams into the caverns of Carpathia to attempt to capture a brood of live Genestealers in a stasis field. The mission was successful, although Kryptman's force suffered heavy casualties. He then planted the brood on board the Perdition's Flame, a Space Hulk that emerged from the Warp in the path of Leviathan. As the Genestealers awoke, he destroyed the moon of Gheist in order to divert the hulk's trajectory directly towards the Octarius Empire.
As the Space Hulk entered the Octarius Empire, it was boarded by Ork Lootaz seeking to plunder it, but they were quickly ambushed and impregnated by the Genestealers. They went on to spread the infestation across the entire Octarius Sector. After preliminary skirmishes with the invading Genestealers, Warbosses from the Blood Axes employed the services of Boss Zagstruk and his Vulcha Squad to intercept and destroy the infestation. Even though they were successful, a tendril of Leviathan changed course towards the psychic signal of the Genestealers and invaded the Empire. The Overfiend of Octarius, Blaktoof, launched a counter-invasion directly into the oncoming Hive Fleet. Despite the Orks' efforts, a dozen worlds in the Octarius Empire became infected by the Tyranids within weeks.[1 ] Depending on the source, the date of Leviathan's invasion is either 989.M41  or 999.M41 .
On the former Imperial world of Orrok, the Orks reacted with puzzlement when the skies darkened with millions of incoming Mycetic Spores. The Orks rushed to their weapons and barely had time to man their defences when waves of Gaunts crashed into the fortifications. The Orks counter-charged the oncoming swarm, and thousands died on both sides in only a matter of seconds. On every scale a fierce battle raged - Squigs and Rippers tore into each other underfoot as Gaunts and Ork Boyz hacked and slashed at each other; Ork Warbosses and Nobz fought against Tyranid Warriors and Carnifexes; mighty Squiggoths battled thunderously with huge Tyranid Bio-Titans; even on a microscopic level Tyranid Phage Cells consumed the aggressively spreading Orkoid Spores. Orrok was encumbered by total war on every scale. But slowly, the Orks realised they were outnumbered and surrounded. By nightfall every Ork on Orrok was killed and their corpses turned into bio-resources to feed the growing Tyranid swarm.[Needs Citation]
Shortly after Orrok fell, Leviathan descended upon Ghorala, the base of Pirate-Warboss Skarfang and his dreaded Skar Fleet. When Leviathan arrived they were countered by every Ork vessel within a dozen light years, as well as extensive mine fields hidden amongst Ghorala's asteroid belt which tore bio-ships apart in cataclysmic explosions. Ork gunships assaulted the surviving vessels before they had time to react and the Tyranid fleet was all but destroyed under Skarfang's guns. However a single bio-ship managed to break through the Ork blockade and hurl itself at Ghorala, heedless of pain or injury. It launched thousands of Mycetic Spores onto the planet's equatorial planes. Skarfang, watching the planet from afar, realised that the space battle was over and the real fight was now on the planet's surface. The Orks made planetfall to chase their foe.
On the planet's surface the Tyranids were vastly outnumbered by Orks, for the first time since entering the Octarius Sector. Sensing that a war of attrition would end in their deaths, the Tyranid swarm adopted a tactic of stalking and attacking only isolated Ork patrols. But the Orks began traveling in mobs too large for the fledging swarm to face. The Tyranids then adapted again and began aiming for maximum carnage by engaging the Orks in the open. Whenever the Tyranids were on the verge of being overrun, they would retreat in unison and shelter in caves or beneath the ground until nighttime, when the Tyranid Synapse creatures would re-gather the scattered beasts to the battlefield to feed on the corpses. Ork and Tyranid bodies alike would be devoured and brought to Digestion Pools secreted in the planet's rocky mesas. Slowly but surely the Tyranids gathered more bio-resources and increased their numbers. The growing swarm changed its tactics again to engage ever larger concentrations of Orks in order to win larger sources of bio-resources.
Skarfang was soon attracted by all the violence and entered the ground war himself. His guttural war-cries encouraged Orks to turn the tide of battles in their favour. With the new battle-lust that Skarfang inspired, the Tyranids were slowly being pushed back. However in response, the Tyranids created Lictors with the purpose of assassinating Skarfang. But Squig-hounds foiled every one of their attempts to get close enough. The Tyranids cunningly lured Skarfang out by throwing tides of Hormagaunts at the Ork lines, and then withdrawing when the Orks roused in defence. Skarfang became infuriated as these feints were repeated from different directions but always withdrew before the Orks could fight back. On the tenth such attack, Skarfang ordered a pursuit. Battlewagons and Wartrukks bellowed after the swarm... directly into a trap. Broods of Venomthropes surrounded the Orks in a thick, toxic fog and the convey of Ork vehicles crashed into rocky outcrops or into each other. As the Orks began to choke to death in the fog, Skarfang stumbled across the Venomthropes and vented his anger on them. But when the fog receded, Skarfang found himself surrounded by Lictors. All his boyz had been killed off one at a time until he was the only Ork left. He managed to take two steps towards the enemy before a dozen claws tore him asunder.
With their leader dead, the Orks on Ghorala collapsed into infighting and became easy prey for the Tyranids. Each tribe was isolated and destroyed in quick succession until, within weeks, all the Orks on Ghorala had been killed. The bio-resources of the planet were turned into new bio-ships and the Tyranid infestation quickly spread to nearby Ork worlds.
On the central world of Octarius, the Overfiend of Octarius, after hearing about Orrok, marshalled the tribes and prepared the defences. When the first wave of Mycetic Spores arrived at the planet days later, a great cheer went up from the gathered Ork hordes who were itching for a great fight. Much of the battle took place in the skies and so much ammunition was fired into the air by Ork Quad-guns and Flakka-Dakka Guns that the rain was thickened by chunks of falling Tyranid flesh. Then from the west the black storm clouds drew closer and closer until they were revealed to be swarms of advancing Gargoyles. Ork Deffkoptas, Fighta-Bommers and Stormboyz roared into the air in a race to intercept the oncoming creatures. Dead Orks, burning wreckage, and hissing Tyranid ichor rained down everywhere.
The Ork Boyz on the ground below began to climb the slopes, holding their Choppas high and intending to jump into the fray if only they could. Then suddenly the ground burst up and Genestealer broods flowed out of the tunnels. But the responding green tide of Orks quickly pushed them back into the crevasses and then plunged in after them. Meanwhile, Lictors scaled the mountainsides and stealthily silenced each Ork gun emplacement in turn. With the large guns down, the rain of Mycetic Spores doubled in ferocity and more and more Tyranids landed on the mountain passes to be met by equal numbers of Orks. Never before had Octarius seen such bloodshed, and the war soon spread from Octarius out to the entirety of the Octarius Sector.
The Octarius war is continuing to escalate. In 997.M41 several Eldar warhosts entered the war, fighting against both Imperial and Ork forces.[Needs Citation] In 990999.M41 many Imperial Worlds were caught in the crossfire as the Saim-Hann Eldar entered the war, and the Raven Guard, White Scars and Salamanders Chapters united to defend the embattled planets.[Needs Citation] Recent reports indicate that the Tyranid Swarmlord has joined the assault on the Orks of Octarius.
Whether the Orks or the Tyranids win the war, the victor will emerge stronger than before. Orks from light-years around are flocking to Octarius, and are growing bigger and stronger on their diet of conflict. And every Ork devoured gives more biomass to the growing Tyranid swarm, which is constantly learning and adapting new ways to defeat their foes. Kryptman succeeded in luring Leviathan to the Octarius Empire, but rather than tricking both sides into destroying each other his plan has backfired into starting a series of events that is making the Imperium's enemies stronger.
- 1: Codex: Tyranids (5th Edition), pgs. 28-31
- 2: Planetstrike, pgs. 57-59
- 3: Codex: Orks (4th Edition), pg. 29
- 4: The Last Ditch (Novel) by Sandy Mitchell: Chapter Twenty, pg. 200, fn. 2