In both material and Immaterial space, trickles of the savage orks migrated all across Ultima Segmentum in a single-minded purpose, drawn towards a singular point. Small, disparate warbands and marauders inevitably met and merged after quick but effective restructuring via the biggest ork of one group krumping the biggest ork of the other group and assuming control. The warboss of the new conglomeration would meet another ork fleet, and if he proved mighty enough, the scene would be repeated. 

 

Through more of such encounters warbosses would grow their fleet, and the lucky few would command a truly terrifying and huge fleet, cramped with ork boyz chomping for a good battle. The select few that made it to the destination were great warbosses in their own right, powerful enough to command WAAAGH!!!s of their own. Yet they converged as one, and uncharacteristically put aside their rivalry as they neared their destination, the mythical warzone where orks never came back from, supposedly because of just how much fighting there was to be had. It was touted as the greatest WAAAGH!!! of all, promising an unending brawl that would drown any greenskin in blissful combat.

 

The truth was far less romantic though.

 

As soon as the warbosses and their fleets entered their destination system, the electronics of their fleet would short out, killing engines, weapons, communications, and force fields. Then they would be fully welcomed by a storm of white beams, and at this point, most of the orks would be blissfully oblivious as they and their crafts were obliterated. The lucky orks would have enough of a corpse to float in space and join the dense debris field of shattered ships and asteroids that filled the transition point. 

 

The really lucky orks would still be alive, and struggle defiantly in the cold void. Most of them would be noticed and picked up by metallic things with too many snaking tentacles, at which point they ceased to be lucky as their limbs were clinically torn out of their sockets and the roaring stumps would be dragged into a cold, dark cell.

 

This illusion of the greenskin’s holy crusade went on for five Terran years, drawing every ork in the segmentum towards the Nexus system of Shroom Doom. So singular and persistent was their migration that the Imperium of Man evacuated systems that lay along major routes, and reports of greenskin corsairs actually fell. 

 

For five years, the orks streamed towards the Nexus, ignoring the Imperium and granting a rare moment of respite for their worlds. Five years that allowed for complacency to grow as the greenskin threat receded significantly across the segmentum. Five years for the Imperium’s human bureaucracy to adjust and take for granted the orks’ migration.

 

And then, the beacon signal in Shroom Doom went silent.

 

Psychic and subspace frequencies abruptly cut off, and the Shroom Doom system itself went dark. The greenskin fleets that streamed into realspace suddenly found the storm of fire gone, leaving them with a cloud of wrecks and debris before them. 

 

There was surprise at first at the sudden development.

 

And then jubilation that the shooting had stopped, so that they could proceed to actual orky fighting.

 

And then, as they landed on the sole, desolate world and found not traces of civilization, not even a floating tincan to offer a decent whooping there was frustration.

 

Where was the great fight they were promised? Where was the horizon-spanning enemies who were begging for a krumping?

 

Days passed, and the fleets inevitably fought against each other to pass the time. More ships poured in and the newcomers went through the same emotional phases. Enough orkish vessels loitered in the system that the augur arrays in neighboring systems could track the collective energy emissions. Psychic scrying saw the congregation as a beacon in the Warp that steadily grew brighter, almost noticeable from glorious Terra itself.

 

As the idle orks spent their time in leisurely carnage, the warbosses convened a meeting to establish what they should do moving forwards. As ork tradition dictated, it began with a free-for-all to determine who was truly in charge. After rivals were mauled or throttled into submission, or just killed off or - in one case - devoured limb by limb, Great Warboss Bloodstompa held court with his nobs and new vassals and was open to suggestions.

 

Some wanted to explore the systems beyond this. Maybe the enemy had retreated, and more fighting could be found there.

 

Others wanted to return to their own stomping grounds, where the fighting was at least assured.

 

Others still wished to pick a bigger, ‘arder target to pick a fight with, since the WAAAGH!!! here was already in such significant size.

 

Then a lone ork kroozer appeared on the opposite end of the system, battered and carved out so badly that it was practically just an engine and a bridge left. From it, a message was roared into the void.

 

“Fightin’s ova! ‘Ere’s nuthin’ left!”

 

The enemy had fled, claimed the speaker. After enduring all the stellar storm of fire, surviving ork ships managed to chase their prey back to their homeworld. When they arrived, the foe did the most un-orky thing: Rather than put up a fight as was propa, they up and left, taking all their guns and gubbins with them. The orks gave chase of course, but the fighting was lousy. 

 

Again, rather than be boarded to fight, the enemy chose instead to self-destruct their whole fleet. The only amusement to be had was that they at least had the sense to do so once most of the ork ships had gotten close enough to be blasted apart as well.

 

All survived was thee broken kroozer, and a band of orks who were so mangled by the fighting that they had stitches all over them.

 

The news quickly spread throughout Bloodstompa’s loitering fleet. The great brawl they’ve traveled light-decades to join was gone. The supposedly ‘ard enemy had proven to be no fun at all. 

 

Discontent followed after the news, and Bloodstompa knew he had to do something, or risk this grand WAAAGH!!! he’d just assumed command of disintegrating so wastefully.

 

The survivors had said that the systems beyond Doom Shroom was barren, and the readings from the mekboyz’ scans backed up that claim. 

 

But those same scanners also picked up that there were other systems nearby. And in those systems, the mekboyz were sure signs of concentrated forces could be found. 

 

Fighting forces. Imperium forces.

 

And there were very much a good dozen or more of such systems ringing this barren void.

 

It was about the next best thing for not just Bloodstompa, but his grand fleet. Word was sent to every ship, and the WAAAGH!!! began to move. Imperial observers were shocked to see the concentration of orks suddenly flooding out of the Nexus system and towards Imperial space once more.

 

The cordon systems around the Nexus were all swamped almost immediately, and it was only due to the extensive fortifications designed by Perturabo that each system held against the onslaught. Innumerable orkish ships thundered their way towards their targets, overwhelming whatever Imperial ship they were lucky enough to come across. Astartes garrison fleets were forced to adopt hit and run tactics instead of facing the tide of welded metal and commandeered asteroids face on.

 

Across all systems, void superiority was hatefully conceded to the greenskin horde. Then orks reached low orbit of the fortress worlds, and to the Imperial defenders, it seemed that it was raining orks.

 

Perturabo’s masterfully planned defenses were strained beyond their limits. Anti-air emplacements quickly ran out of ammunition or required maintenance as they struggled to offer a minimum of local air security. The same occurred to bunkers and entrenchments overlooking killzones and tactical bottlenecks - either ammunition ran dry, or the guns that fired them ran too hot to be used anymore. The overrun defenses obliterated thousands of orcs as they self-destructed, but still the tide did not abate.

 

Missile silos quickly expended their stores of even the most exotic stock of vortex warheads, life-eater virus payloads and magmabreaker warheads to try stemming the advance from all sides. The missiles were launched into the ships in orbit or the greatest concentration of the xenos on the planet, removing countless thousands more of the aliens.

 

But still the orks smothered the worlds.

 

Across planets of the cordon systems, legionnaires valiantly fought back the green tide, but were forced to give ground to withdraw and regroup far faster than the Lord of Iron had planned for. The layers of his defense in depth that were each supposed to last at least for weeks were now being overrun in days. Even with the zealous fury of Lorgar’s Word Bearers aiding the Iron Warriors, the Imperial presence in each cordon world was reduced to a few strategic strongpoints within two standard weeks. If not for Perturabo’s doctrine, the Iron Warriors and Word Bearers defenders would have faced extinction fighting to the last.

 

Even then, after falling back to their last strongpoints, that possibility still loomed as the orks continued to throw themselves into the guns and blades of the battered defenders. In some fortresses, the legionnaires resorted purely to holding the breaches with brutal melee as their ranged weapons had been fully expended.

 

And with the voidspace of each system being held practically uncontested by the greenskins, extraction was impractical.

 

It was only through the intervention of the Ultramarines, Death Guard, Emperor’s Children and - to the surprise of all - Night Lord fleets that impending doom was averted. Redirected from their hunt of Angron, the fleets of the IIIrd, XIIIth and XIVth joined their surviving IVth and XVIIth cousins in coordinating breakthroughs, punching through the ork fleet with discipline and righteous fury.

 

Fleet commanders across various theaters of war orchestrated daring and brilliant maneuvers that carved out a corridor towards the beleaguered worlds. Desperate rescue operations were conducted to extract the exhausted defenders from their last stands, and countless acts of heroism were recorded in the process.

 

Lorgar held off a whole wave of ork combat walkers by himself as his and his brothers’ legionnaires evacuated, at one point throwing the walkers into the ork tide with his bare hands. He left the planet with only scraps of his armor hanging off him.

 

A lone Iron Warrior apothecary faced down an ork boss and his retinue with only his narthecium injector as the reactor behind him counted down to a catastrophic detonation. The timely teleport retrieval allowed him to live to tell the tale with only the loss of his legs.

 

Fulgrim dove straight into the alien tide in a drop pod and slaughtered whole fields of them to clear a safe landing zone. His elite Palatine Blades forged their own legends in keeping the landing zone safe, with the two members who fell only doing so after they were half-buried in ork corpses.

 

An Ultramarine dreadnought squadron held the line as the Iron Warriors evacuated their grievously wounded primarch. Each interred pilot fought to the ruinous last as the transport left, fighting on even as their walkers were eventually crippled and broken, detonating their reactors as their last act of defiance.

 

A squad of Death Guard assault marines jumped off their Thunderhawk transport and used their jump packs to hop from one ork aircraft to another, killing the enemy pilots to help reduce the enemy air presence for evacuations to commence.

 

On the worlds where the unexpected aid of the VIIIth Night Lords was offered, the orks were chased away from the evacuation zones by excessive displays of violence. Konrad Kurze faced down and flayed alive no less than three ork warbosses and their retinues, breaking the will of their hordes for just long enough for the legionnaires to abandon the walls. His sons enacted similar atrocities, screaming through the dark to sow chaos and terror in exchange for precious seconds to evacuate.

 

Evacuations of the fortress worlds were heavily contested, but ultimately successful. Only four worlds were completely lost to the orks, their surfaces rendered to an ocean of molten lava as the final denial from the last strongholds was enacted and cyclonic warheads cracked and destabilized the planets’ crust and mantle.

 

Battered and exhausted, the survivors of the cordon systems and their rescuers then had to fight off the greenskin fleets as they withdrew. The ork invasion was an overwhelming defeat for the Imperium, and unfortunately for the legions, the stalwart defense they put up against the green tide only served to entice the battle-hungry species.

 

The worlds of Ultima Segmentum were mobilized to full alert as the green tide began to spread all along the Green Pilgrimage. Most of the persecution fleets were called off their pursuit of Angron and his rebels in favor of defending the Imperium’s holdings. Even Leman Russ called off his legion as a significant element of the ork WAAAGH!!! advanced towards their homeworld of Fenris.

 

When the issue was presented to them, the envoys in the Nexus Unity’s embassy provided a wholly unsatisfactory reply.

 

“We found it untenable to keep fighting off the green-skinned invaders. So we tried to simply stop doing so. We did not expect the result to be so…dramatic.”

 

Malcador could not press for satisfaction, as the orks had originated from Imperium space and were allowed to converge on the Nexus in the first place. On a strategic scale, this was akin to breaching a dam and watching as the waters retook the lower-lying lands.

 

With the chaos of meeting the ork horde drawing attention away, it was no surprise that Angron and his World Eaters managed to reach the Nexus to claim asylum. Through avoiding most of the battles and preying on smaller ork fleets for emergency parts and supplies, the rebelling legion limped its way towards the borders of the Nexus Unity. They also encountered seemingly abandoned Imperial merchant ships, laden with supplies that were likely meant to reinforce the now broken cordon systems. Ammunition, fuel, components, the timely drops of resupply were much appreciated and thought little of.

 

Only Angron noticed the subtle messages scratched into the hulls of those ships, and he silently hoped that Konrad had not offered such gifts at the bloody price of the ships’ crews.

 

Once they finally crossed into Nexus space, the battered ships were guided by automata battlecruisers and destroyers to dock at a planetoid-sized space station.

 

There, Angron marched out with his commanders towards Sev and his own favored retinue of demigods. To the stiff surprise of his sons, the primarch knelt before the eldritch ruler of the Nexus Unity.

 

“Lord Sev, on behalf of my legion, on behalf of my sons who are being wrongly persecuted for defending humanity in all forms, I seek sanctuary within the Nexus Unity from the Imperium of Man.”