The Overmind truly never imagined he would witness the "T'au of Nurgle."
It seemed the rot of the Milky Way was truly universal; not even the optimistic T'au could escape the creeping decay of the Warp. The Overmind shook his collective head. In this galaxy of ancient hatreds and veteran horrors, was there no force left that remained untainted?
"Yes, brother, there is," he mused.
This brings us to the newest players on the galactic stage: the Leagues of Votann—the Space Dwarfs. It was their quiet cooperation and technological trade that had allowed T'au science to leap from primitive black powder to pulse weaponry and railguns in a mere six thousand years. But even that advanced technology couldn't save this particular colony.
"Oh, you poor Blue-skins," the Overmind mocked. "You should have sworn allegiance to the Swarm. Instead, you've traded your 'Greater Good' for the Grandfather's 'Generosity'."
He watched through his Eyeworms as a sizable T'au fleet—corrupted and weeping with filth—left the planet's orbit, heading toward the last known coordinates of Zasz's vanguard.
"Hehehe, the fish has taken the bait! But at their sluggish sub-light speed, it'll be a long time before they reach the trap."
The Overmind was in no hurry. For a being of his cosmic scale, time had lost its sting. He could wait. Besides, the Swarm had been expanding at a breakneck pace; it needed time to digest its gains, consolidate its resource nodes, and allow Abathur to finish his latest genetic sequences.
"Still... this Nurgle-infested rock is an eyesore," the Overmind decided.
He no longer feared the Four Gods of Chaos. Unless the Ruinous Powers manifested personally, a few Greater Daemons—or even a dozen—were merely biomass waiting to be reclaimed. It took more than a hundred Greater Daemons to besiege Holy Terra; this backwater planet would be a footnote.
"Let's clean this up."
It had been a while since he had personally clashed with the forces of Nurgle. He decided to take direct control of the assault, simply to kill time.
What the Overmind didn't realize was that the ruler of this randomly chosen world was no minor rot-priest. This planet was the domain of Rotigus Rainmaker, the "Generous One." Rotigus was the second most favored Great Unclean One in Nurgle's garden, a daemon of torrential decay who had risen to even greater prominence after the Plague Wars.
The T'au here were the descendants of an early expansion fleet that had lost its way due to instrument failure. Stranded and desperate, they had fallen under the "protection" of the Rain Father. Now, they were nothing more than hollowed-out slaves to the Great Impure One.
The Overmind didn't care about their history. He only cared about the expansion of the Swarm.
"One Leviathan should be enough. I see no defending fleet."
Without a fleet to contest the high anchor, a single Leviathan was an invincible fortress.
"Abathur, ensure the landing force is reinforced against viral and necrotic pathogens."
"Strains adjusted," Abathur's voice rasped in his mind. "Applied chitinous density from the Tiamat Hive. Immune systems overclocked. Swarm will endure the rot. Consumption is inevitable."
The Overmind began the descent, personally guiding the drop pods through the atmosphere. The moment they breached the clouds, they were met by the palpable malice of Nurgle. The air was a soup of hyper-evolved pathogens and life-choking spores. To a Tyranid swarm, this environment would require immediate, painful adaptation. But the Zerg had encountered Nurgle before. Their DNA was already "patched" against these specific glitches.
The first wave landed in a vast, weeping mushroom forest outside the main city. The gargantuan fungi released clouds of deadly spores when disturbed, but the Zerg ignored the toxins entirely.
The forest was teeming with Poxwalkers—mindless T'au and other xenos slaves who had been "blessed" by the forest's rot. They wandered aimlessly until the shriek of the Swarm caught their attention. They turned their decaying heads just in time to see a purple tide of Zerglings erupting from the treeline.
The Nurgle-slaves were slow and dim-witted. Some shuffled toward the noise, only to be swallowed by the sea of claws in seconds. The forest fought back, spraying enough spores to bypass even a Zerg's respiratory filters, but the sheer wind pressure generated by the Swarm's movement pushed the toxins skyward, clearing a path for the second wave of pods.
At the town gates, several Plague Marines of the Death Guard stood watch. It was a tedious duty; they hadn't seen an intruder in decades.
"This is mind-numbingly dull," one Marine grunted, his voice bubbling through a rusted vox-grille. "I'd rather be on expedition with Lord Abaddon."
"Talk less, brother. Perhaps Lord Typhon will soon lead us against the Corpse-Emperor's lackeys again."
The Plague Warriors' complaints were cut short by a sound—a low, chittering hum that vibrated in their very marrow.
"What was that? Your ears finally rotting off, or did you hear it too?"
"No... I heard it."
The Marine looked toward the Spore Forest and gasped. A deluge of alien beasts was pouring out of the rot, their numbers so vast they turned the horizon purple.
"Grandfather save us... where did all these beasts come from?!"
The Plague Marine raised his bolter and opened fire. The Zerglings, though reinforced, still burst under the impact of bolt shells. But for every Zergling that died, three more leapt over its remains. Before the Marines could even cycle their second magazines, the Swarm was upon them.
Zerglings pounced, their talons screeching against the rusted ceramite armor. The Marine swung a heavy, plague-encrusted fist, bursting a Zergling in a spray of ichor, but he was already being buried under a dozen more.
"They're... so... fast!"