Brother Orias' flamer guttered out with a wisp of oily smoke. The blessed promethium ran dry in the face of this teeming nightmare. He cast the useless weapon aside with a sigh, feeling the press of claws against his backplate. So this was to be his end.
The Librarian had become a puppet, blasting wildly into the swarming hordes around them. The psyker's overloaded mind had shattered at the touch of the entities from beyond the veil. There would be no disruptions of the ritual's power now.
Gregor roared his fevered defiance, but his crusader's zeal was broken. The things closing in around the dwindling circle of light were beyond his power to banish back to the warp. This planet was theirs and had been for longer than mankind had sailed the stars.
Reality itself was unraveling, the laws that governed material existence crumbling in this place where belief and ritual gave form to that which should not be. The night was their playground when the skin of waking worlds wore thin.
Onwards shuffled the legions born from ancient fears and fevered imaginings. Their forms spun wildly through shapes and configurations as if seeking the most awful resonances with the human soul. Fangs and talons rent armor as they pressed in for the feast.
Brother Malius was pulled down screaming into the dark, armor cracking open like an egg. Unspeakable fluids steamed from the crevices as the battle-brother was consumed from within. His psychic death-cry echoed in their minds.
Green lightning arced from the leering effigies erected around the ritual stage. The veil was parting, banishing any hope that reinforcements could now turn the tide. There would be no escape from the planet's curse.
Laughter rolled across the square as cultists in tattered orange robes danced in growing frenzy. The elder's rasping voice carried upon the din: "Come forth oh ancient ones! The stars are aligned once more!"
Gregor's heart jolted as macabre puppet shows and street plays across the square seemed to twist into reality. The rituals feeding this night were reaching an apex. This was more than mere warp incursion; the boundaries of real space were unraveling entirely in fealty to ancient curses.
Squatting things that never were on Earth capered and jabbered around shimmering fires. Blackened tongues tasting the air, hungry for the electric tang of souls torn from their moorings. The Librarian's drained corpse collapsed; armor rent open in sacrifice.
Brother Garus fell back, clutching at the sucking chest wound torn through blessed ceramite. His shattered helm revealed a face etched with mortal dread, eyes pleading for deliverance. Gregor could only offer a bolter round of mercy as the darkness took him.
Cruel laughter rattled from skinless lips as Gregor emptied his clip into the flayed muscle and sinew of a clawing fiend. He drew his sword as eldritch flames swirled around the closing foe. Steel was no shield this night.
Reality blurred as ghastly smells and sounds struck from all quarters. Night gaunts fluttered overhead, waiting to bear them off into the hidden spaces that laughed eternally at human ignorance. The planet was theirs.
Betimes Gregor perceived the scene as a private hell dimension exuding from his mind alone in fevered solitude. But the rending of joints and bite of blades dispelled each false hope. This darkness was older than any soul here.
Chants and piping melodies swelled as the swirling energies built into a howling crescendo. The ritual entered its final stage beneath the silent black moon leering like a cavernous eye socket. Soon they would be subsumed into the roiling chaos.
White noise drowned all thought as psychic disruption failed. Twisted beings drank in the power, melting into new atrocities. The veil was gossamer thin now, barely containing the awful pressures from beyond. Reality was laid bare in all its rugged savagery, with no laws to shield mortal minds.
A child's plea rang over the din – "Help me! It's almost here!" Gregor saw a small form fleeing across fracturing rooftops, pursued by shrieking darkness. Then the vision boiled away as clawed horrors circled for the kill.
Bone and iron could not avail against the flaying knives and barbs wielded by the children of ancient nightmares. Their ticking and twitching motions spoke of a wrongness beyond geometry. All flesh would feed the endlessly hungry void this Night of Nights.
Gregor screamed unheard defiance through ruptured lungs as the hooked chains dragged him toward the yawning pit at center stage. similar fates awaited any who clung desperately to their paltry human shells. Death was but the first step in their coming aberrant transfiguration.
As corrupted psy-lightning immolated his being, Gregor glimpsed impossible shapes moving behind the tattered veil. The Old Ones had returned to claim long-lost dominion over their wayward mortal supplicants. All Hallows Eve World had awakened once more.