“Nileas!” Ausrius bellowed again. He could find no trace of his fellow, even with his enhanced senses, and helmet overlay. No trace of the daemon either.
He surveyed the cavern again, slowly re-examining all the corners. He checked the load in his bolter, and advanced, weapon at the ready, continuing to scan in visible light, infrared, and wireframe overlay. The ripples and folds of the tunnel played tricks on the mind, casting odd shadows and concealing entire caverns behind seemingly solid formations of stone.
“Nileas,” he voxed again. “Brother, do you copy?” Likewise the dense rock played havoc with the vox net. He had no contact with his squad commander, or Imperial forces on the surface, and, up until a quarter-hour ago, only intermittent contact with his battle brother, and that plagued by static. Now it seemed that too was gone.
Something slithered across stone nearby; something massive. Ausrius turned sharply, bringing the bolter up. He couldn’t see it, but it was dangerously close. He moved forward, stalking the hideous presence. Though he and his squad were nominally doing the hunting, he could not shake the feeling of being hunted. He heard the clicking of insectoid limbs and mouthparts; the heavy slithering sound again. Overlapping echoes, reflecting and magnifying sounds in unpredictable ways, made it impossible to tell where the source of the sound was.
He slowed, almost shuffling as he came around a shoulder of stone into an entirely new section of the cave.
The broad chamber was dome-like, and smooth, the space carved out over millennia by the slow trickle of water. Stalactites depended from the ceiling in eerily organic formations. Stalagmites of formidable stature loomed from the uneven floor. Some were as large around as Ausrius himself. Others were even larger. A damp mineral smell pervaded, but Ausrius’ charmed senses detected notes of other things; Astartes sweat ripe with glanded stimulants and pain suppressants. The burned-metal and melted electrical smell of damaged ceramite armor. Blood. Nileas had passed through here. The scents told him his brother was hard pressed, but gave him some thin hope that his fellow yet lived. There was also an odor of organic decay, rancid meat, ozone and cold – that was the warp beast.
The thing lurked here somewhere. Even without the smell, Ausrius could sense its hateful existence. It was like a cold whisper down the back of his neck. A feeling of utter wrongness. But he still could not see it.
He saw Nileas first, leaning heavily against a stalagmite formation. His battle brother was sorely wounded, even his gene-hanced physiology laboring under the awful damage he had taken. His beautiful red and gold power armor was dented and sheared apart, splashed with bright blood. His left pauldron had been torn away completely, as well as the lower vambrace and gauntlet. His naked hand, large as it was, seemed tiny and fragile against the bulk of his armor. The chainsword in his right fist snarled at idle.
“Nileas.” Ausrius started forward to his brother’s aid.
Nileas’ helmet was also gone, but he did not need the vox speaker to amplify his formidable voice; “Keep back!” He threw up his left hand, bloody palm out, to emphasize the command. “It is here.”
The thing was on them in that moment. It moved like lightning, like a striking serpent, and a spider, and every terrible thing imagined by human nightmares. It was too big to move that fast!
Ausrius unloaded his bolter at it as it dove and surged around the chamber. It had too many limbs and too many joints in those limbs and parts of its body were like smoke or oil, shifting and reforming in ways that made him nauseous to behold.
Nileas tried to keep his face toward the thing, his back to the stone, and always the purring chainsword between them.
The atrocity suddenly threw itself at the wounded Astartes. Its face – if such a perversion could be said to have a face – split apart, the lower half of the elongated, skull-like head separating into four greedy mandibles. It’s tooth-lined maw was large enough to swallow a Space Marine whole, power armor and all.
Nileas braced, holding the chainsword out, ready to meet the thing head on.
Ausrius poured bolter fire down its throat. It squealed, shrieked and writhed in on itself in impossible ways. Ausrius shuddered with revulsion, but kept shooting, reloading when the magazine ran empty.
One mis-jointed limb shot out and impaled Nileas with a blade-claw more than a meter long. It sheared through his ceramite armor like it was nothing. The Astartes groaned aloud. Ausrius roared his fury. Nileas struck, slashing off the blade-limb even as it was withdrawn with the same uncanny speed. The chainsword bit through hard carapace and fleshy inner parts, the blade snarling and gurgling. Hurt, the daemon wheeled, flailing limbs and loose coils of itself. It threw Nileas to the floor before boiling away into the shadows, into the next chamber down the tunnel.
“Nileas!” Ausrius charged to his brother’s side and knelt protectively over him, the bolter still held ready.
Nileas groaned again, blood ran from his mouth. He was panting for breath and Ausrius thought he might be relying entirely on the smaller third lung. Blood poured from the wound. Normally Astartes blood clotted quickly, they were fast healers and could weather monstrous amounts of punishment and brutal pain. But Nileas was past all limits.
“I’ll get you out of here, Brother,” Ausrius promised.
“Fortitude,” Ausrius urged him. He slung his bolter across his back and lifted Nileas’ shoulders, supporting him to ease his breathing.
“Fortitude,” Nileas agreed, “and faith. You will need both... for this mission. Take it.” He pointed toward the chainsword. He had dropped it when the monster threw him down and the blade had cut off automatically.
Ausrius hesitated. “My brother,” he said, “I don’t understand.”
“You must finish it,” Nileas charged him solemnly. “Destroy that abomination. Burn it from existence. In the Emperor’s name. You must not fail in this.” He spoke haltingly, as his breathing labored, but with fierce conviction.
Slowly, Ausrius understood. Still cradling his dying battle-brother with one arm, he reached out and grasped the hilt of Nileas’ chainsword and lifted it. The elder Space Marine nodded. “Finish this,” he sighed, at the end of his strength.
“I will, Brother.”
“Swear.” Blood pooled on the stones beneath them, and dripped from his mouth.
Fighting despair at the weight of responsibility hanging over him, Ausrius drew a tight breath. He firmed his grip upon the chainsword, the heft of a ready weapon always a comfort. It was an ancient and venerable piece, marked with a roll of honor stretching back into the far history of Kermodes Squad. Dozens of Howling Griffons heroes had carried this blade into battle for Guilliman and the Imperium, for the Emperor. Drawing his strength from their memory, and their example, he improvised an oath; “Upon this weapon, and by the Throne of Terra, I swear to pursue this mission until I have succeeded, or until I am dead.”
Nileas reached up and pressed the bloody palm of his left hand to Ausrius’ cuirass, a make-shift seal to witness and acknowledge the oath. He let the hand fall and his head rolled back. He was failing; this nigh-immortal super soldier, this hero, was sliding rapidly down to death, and Ausrius could not help him.
“Brother,” the younger Astartes began.
“Go,” Nileas charged him. It was a whisper, but it carried such weight of authority it could not be refused.
Ausrius knew every moment he lingered was another moment the warp-beast had to make good its escape. He loathed the thought of abandoning his battle brother to die alone, but he also knew Nileas expected him to place duty foremost. Gently, he lowered Nileas to the ground. “Rest easy, brother.”
Nileas could not answer. He clasped his armored right fist across his ruined chest, a warrior’s salute. He closed his eyes against the pain of each shallow, sucking breath.
Ausrius steeled himself and turned away, advancing in the direction the monster had gone. As much as he wanted to, he did not look back. His brother would not expect such sentimentality, and the beast could strike again at any moment.
He held Nileas’ chainsword right-handed, in a low guard, and drew his bolt pistol with his left hand. The bolter rode by its sling, in reserve. He had also the simple but reliable gladius, and three grenades. It wasn’t much. He hoped it would be enough.
The beast had left its scent like spoor and Ausrius followed that, trying not to gag on the stench of corruption. Black, oily fluid pooled on the stones in places, faintly sizzling; the noxious ichor which served the thing as blood. They had hurt it, and if it could be hurt, it could be killed.
He paused as he heard it; slithering, chittering to itself. It sounded like it was right beside him, though he could not see it, the acoustics of the cave playing tricks again. He moved steadily forward, ever vigilant. He could smell ozone and felt the unholy chill he associated with psykers and the warp.
It almost escaped. He came upon it just as it approached the portal. Ausrius had never seen anything like it. It was a hole in reality. A cold rush of air, and faint mist drifted out of this impossible gateway.
The warp daemon sensed his approach and turned its neck inside out to bring its obscene head around to face him. It flared its mouthparts at him. It seethed, limbs and spines and eyes and hungry mouths full of teeth appearing and disappearing across its flesh in a wave that traveled down and around its length. It was taunting him. It made a wet, basso, shuddering, purring sound and rolled like a water serpent in a spiral swimming motion into the portal. It flowed into the unreality as if sinking through the surface of a mirror.
Ausrius had seen many terrible things in his decades of service with the Adeptus Astartes. He had weathered them with commendable stoicism, but now he wavered. Astartes do not feel fear, but alone in this dark desolate place, faced with such an unspeakable monstrosity, and the prospect of following it through a warp gate to an unknown destination, Hellan Ausrius came very close. How could he, alone, hope to succeed against this?
He controlled his breathing, willed his racing pulse steady. He swallowed the bile which had risen in his throat. He fought down the urge to vomit, conquered the tremor in his limbs. He recalled his oaths, and his debt to Nileas. He had no choice, he had to proceed. He clenched his fist on the grip of the chainsword and thumbed the activation stud. The blade snarled into life. Leading with that august weapon, and with a prayer to the God-Emperor on his lips, he strode forward into the warp gate.