"Is there anything else you need before we part ways, Chief Custodian?" Grandmaster Azrael asked, his voice carrying equal amounts of relief and anxiety.
"No. The Custodes and I must return to Terra before Lord Guilliman becomes suspicious about our absence." Trajann Valoris said, striding down the halls of the Rock next to Azrael with his entourage in tow. "The Minotaurs along with our Inquisitorial detachment are being sent to Imperium Nihilis to investigate the Wolf's whereabouts and activities, as well as to suppress any evidence of his treachery or unrest that may arise in his wake. This leaves the searching of the Rock for the Lion to you and your Dark Angels."
"To think… that the Lion was here beneath our noses the entire time…" Azrael mused.
Trajann stepped into the open doors of a Custodes Orion dropship, preparing for takeoff. He turned to Azrael for a final word before departing.
"You must find and awaken the Lion as soon as possible, Azrael. If you do not, we will be forced to return here and do it ourselves. Should this happen, I can assure you… we will not wait for you to raise your shields again." Trajann said ominously.
The doors of the dropship whirred to a close, punctuated by the sound of hissing air as the interior pressurized. The golden voidcraft fired up its engines, rising into the air of the hangar and quickly accelerating beyond the shielded interior into the vacuum of space. Azrael was left standing in silent disquietude.
The Supreme Grandmaster gathered the innermost members of his inner circle into the most secure room of the Rock as the Custodes and Minotaurs' fleets withdrew. To say the atmosphere in the room was tense would be a gross understatement. 7 Astartes sat in the meeting room: Nephalor - the Grandmaster of the Fleet and captain of the Rock, Razaek - Grandmaster of the Apothecarion, Ezekiel - Grandmaster of the Librarius, Sapphon - High Interrogator and Grandmaster of Chaplains, Sammael - Grandmaster of the Ravenwing, Belial - Grandmaster of the Deathwing, and Azrael himself.
"You all know why we have gathered here…" Azrael said. "Right now, we face the gravest challenge to our ranks since the Heresy itself… and the Great Betrayal."
Several of the men in attendance winced at the mention of their most shameful secret.
"But do not be disheartened. For wrapped within these most dire of events has been delivered to us the greatest news we could ever have hoped for - so much so that I doubt any of us knew we could even hope for such a thing. Not only is our Primarch, our genefather, the great Lion El'Jonson alive, but he is here on the Rock at this very moment! The Emperor himself has declared it so!" Azrael said, slamming his fist upon the table with a zealous fervor.
He stood up and turned his back to the rest of the Grandmasters.
"We have been given a chance to redeem ourselves. To undo the wounds wrought upon our legion by the Fallen and allow us to be forgiven in the eyes of both the Emperor and the Lion. Our success in this mission will decide the fate of not only ourselves, but the entire Imperium."
Azrael turned back to his men.
"We must scour every inch of this fortress. Every wing, every chamber, every room, every crevasse. We will shine the Emperor's light upon every dark corner of this damned rock until the Lion has been found." Azrael said.
"Supreme Grandmaster, if I may…" Chief Librarian Ezekiel said. "The depths of the Rock have been sealed for millennia… and with good reason. Therein lies untold amounts of cursed artifacts, banished horrors, forbidden archeotech from the Dark Age of Technology, and other dangers unknown to anyone still alive in the Galaxy…" Ezekiel said, his voice unwavering. "Finding the Lion is our utmost priority, but we must be prepared for what we may unleash in the process."
"Remaining here in uncharted space will allow us to maintain a safe quarantine." Fleet master Nephalor said. "That way should anything be unintentionally set loose, it will be trapped on the Rock with all of our forces where it can be dispatched safely."
"Excellent." Azrael said. "Since we do not know the threat posed by these potential dangers, we will be sending our best troops to search the bowels of the Rock. The Deathwing, the Ravenwing's Black Knights, and all of our best champions. Try to involve as few of the newer recruits as possible, we still have not determined whether Guilliman has hidden any spies amongst the Primaris reinforcements."
"The Deathwing will be ready within a week." Belial said.
"As will the Ravenwing." Sammael said.
"Good." Azrael said. "Go now and gather the ranks. We must prepare ourselves for our ultimate trial. May the Emperor guide our path."
Elsewhere, in the Immaterium, beyond the 4 realms of the Ruinous Powers and the pale wastes which separate them, deep in the folded layers of unreality closer to the heart of creation than anywhere else accessible to higher beings, laid an immense complex of ancient stone and arcane machinery. It was a sprawling maw of black-smoke-spewing smelters and fire-belching furnaces, a nigh-infinite maze of manufactories and workshops. It was the Forge of Souls, a daemonic factory from which the majority of malefic arms and armaments of Chaos were sourced. All four of the gods called upon its services, and as such it was firmly neutral territory in the Great Game. Beyond its immense walls of black steel and obsidian, hordes of greater and lesser daemons jostled and brawled for the opportunity to be chosen as a candidate for binding, to be placed in a mechanical vessel and unleashed upon the Materium without the limits an empyrean being such as a daemon would normally face in realspace. However, there was another side to this bargain: the daemonic engines produced by the Forge of Souls were eternally bound to it and its foreman. Should the Forge ever come under attack by one such as the Chaos Gods themselves, all daemonic engines were curse-bound to defend the Forge to the death: even if it meant turning against their patron god.
As such, the interior of the Forge was a mystery to even the Gods of Chaos, and the daemons that were bound within it did not recall anything about their experiences save for the excruciating pain it entailed. Even still, rumors spread among the denizens of the Warp of strange beings that walked the ancient halls of the Soul Forge, spoken of in quiet whispers as perhaps the original creators of this primordial structure that even the gods themselves did not remember the construction of. So secret were its operations that its enigmatic master, Vashtorr the Arkifane, had not been seen or even known by most of the universe until his increasingly open activity once the Cicatrix Maledictum had been opened.
Within this daemonic foundry, sequestered away in a chamber near the beating heart of the Forge of Souls, a metal giant, bound in chains, hammered away at his most recent project. He was a towering golem of cursed metal and daemonflesh, the two substances so intertwined that they were indistinguishable from one another. Cables and wires coiled and curled across his artificial muscles like nerves beneath his metal skin, his bones replaced by dense frameworks of intricately crafted machinery. His face was a menagerie of sensory interfaces crudely shaped into a semi-human visage, making it unclear whether it was a sincere attempt at replicating its owner's previous appearance or merely a mockery of it.
He held in one hand an archaic hammer, its handle made of some material so ancient that while it had the appearance of wood it was likely that the tool was crafted before life itself could provide timber. The head of the mallet was made of a dark meteoric alloy, forged in the heart of the first star and inscribed with writing indecipherable to all but the Aeldari gods, if any still lived to read it. In his other hand he held a daemon-crafted artificer weapon, appearing smaller than it actually was in his immense grasp. Using the hammer and the innumerable precision instruments fused to his fingers, he labored tirelessly to shape the weapon into a true masterpiece, a deadly implement that would enhance the armory of any daemonic army that wielded it. He raised the weapon to one of his ocular sensors, analyzing the artifact down to the nanometer to ensure it was exactly as he wanted it. This one had taken him over 7 months to create - relatively quickly compared to the others. Satisfied with his handiwork, he threw the weapon over his shoulder and into a pile of thousands of identical copies.
He shuffled over to an open flame and removed a red-hot blade from the magma forge, wiping splattered droplets of molten metal from his forehead. He always kept several different projects going at once, as a single finely produced masterpiece wasn't nearly enough to keep his mind occupied. As he plunged the blade-piece into a pot of boiling oil, he heard the sound of ratcheting machine-legs approaching over the hissing noise of the blade being quenched.
"What do you want, Vashtorr?" Perturabo said, in a decidedly unenthused tone of voice.
"Why, I was simply checking up on my most prized asset." the spindly techno-daemon said, his voice chittering and hissing like a broken voxcaster. "Unlike your previous owner, I actually prefer to take care of my tools. It's such a shame your creator didn't see the immense potential you hold." Vashtorr said, wringing his mechanical digits.
"I will repeat myself. Why are you here?" Perturabo said.
The chained Daemon Primarch shuffled over to another worktable to attend to a third project, his footsteps weighed down by the chains around his waist and legs. The supernatural shackles did not actually bind him to any single location, they were merely a psychic manifestation of his service to the Forge of Souls.
"I saved you from oblivion, 'Lord of Iron'. The least you could do is show me some respect…" Vashtorr said mockingly, his wide, incandescent eyes inches away from Perturabo's face as he poked him in the chest. The Primarch's metallic visage remained thoroughly expressionless.
"I will repeat a third time. Why are you here?" Perturabo said.
Vashtorr sighed.
"I'm leaving the Forge for a time for a little excursion into realspace. I need you to look after everything while I'm gone." Vashtorr said.
"I thought you were going to wait for the Warmaster's next campaign to make your move?" Perturabo said.
"That was before a little bird told me that my intended target was sitting alone and unprotected in a remote region of space as we speak… and sent me the exact coordinates of said target." Vashtorr said. "I have more than enough of the Warmaster's troops to take my quarry now that it's isolated and undefended. Today really does feel like my lucky day, don't you think?"
Perturabo grumbled unintelligibly.
"Well then, I'm off. Keep the forges hot for me." Vashtorr said, his mechanical joints whirring as he made his exit. "Soon, the Rock and all of its secrets will be mine."
Mortarion sat upon a throne in the bridge of his personal transport vessel, the Psychopomp. It was lean and agile for a plague barge, yet still packed a wide array of toxic weaponry. It almost had the appearance of an emaciated whale carcass as it cruised along the turbulent winds of the Immaterium, breaching through waves of chaotic warpstuff with its skeletal prow. Mortarion slid his fingers across the blunt edge of his greatscythe as he awaited a response to the emissary he had sent to the Word Bearers.
"What do you mean they haven't seen their Primarch in centuries?" Mortarion said to his astropath, an edge of annoyance in his voice.
"They said that the Urizen is meditating in a remote temple in the polar north of Sicarus. They haven't dared to intrude on his isolation because the forest that the temple is located in is supposedly haunted by a dark spirit." The astropath said.
"A dark spirit? Oh for the love of-" Mortarion said, slamming the hilt of his scythe on the floor. "Those gods-damned Word Bearers and their fucking superstitions. It's probably just a feral daemon or warp predator that's wandered in and taken up roost in some abandoned building."
"We're coming up on Sicarus now, my Prince." The navigator said.
The Psychopomp emerged from the tear in the Immaterium into realspace, carried on churning currents of psychically charged aether that quickly dissolved when cut off from the energies of the Warp. The daemon world of Sicarus was nestled in the violent warp storms that permeated the Eye of Terror. In fact, the world orbited no star; it was illuminated by the ambient energy of the chaotic power that surrounded it. Its surface was as disorderly as the warp-currents in the void above it, a swirling patchwork of biomes and climates which seemed to gradually shift and change before their eyes. It was a true site of pilgrimage for the followers of Chaos Absolute, a physical representation of raw discord and pandemonium.
"The Dark Council has sent us coordinates to the Templum Inficio where Prince Lorgar was last seen." The astropath said.
"Ready my shuttle and escort. We will see how this "dark spirit" stands up to the edge of Silence." Mortarion said, rising from his seat and slinging his immense scythe upon his back.
Mortarion's Stormbird touched down on a patch of barren earth a few miles from his destination, the transport having been unable to penetrate the thick warp-charged interference that surrounded the Word Bearer's monastery. This region of the planet appeared to be an arid desert at the moment, complete with dry, cracked earth and a searingly hot sky despite the absence of an actual sun. Mortarion's heavy boots kicked up small clouds of dust as he stepped onto the arid soil, as did the footsteps of the 4 Deathshroud and the squadron of plague marines which followed him. The uneven terrain and often treacherous passages they would have to traverse made using land transports impossible, meaning they would have to travel on foot.
After a mere hour of walking through the desert they had already descended into a swampy marsh, buzzing with flies and crawling with insects. However, on the horizon they noticed a fast-approaching storm and sought shelter in a small alcove above the stagnant waters of the swamp. The storm brought freezing winds and frigid rain, turning the entire marsh into a flat surface of solid ice. The Death Guard continued their trek to the temple, crossing a wide variety of hostile biomes and terrains along the way.
Eventually the Daemon Prince and his escort reached a great forest of tall, black-barked trees that had the texture and appearance of granite or petrified wood. Their leaves were grey with pointed tips of red, like blades wetted with fresh blood. The woods were silent and devoid of life save for the trees and the strange red creep that covered the ground, some kind of flowering moss or fungus with small white buds. The band of Death Guard continued down a narrow pathway through the trees marked by worn and bare earth and an occasional cairn of black stones. The blood-red light of the sky shone through the canopy overhead like a great crimson eye casting its baleful gaze upon the ground below, draining everything of its color and causing the Death Guard's uniforms to become a wash of greyscale and red just like their surroundings.
The metallic clanking of their rusted armor echoed throughout the silent woods, punctuated by the faint wheezing of Mortarion's facemask. The Primarch towered over his men, having easily been the tallest of his brothers even before he had ascended to daemonhood. His folded paper-like wings were curled around his shoulders like a veiny cloak, and upon his back the skeletal greatscythe Silence was slung. They passed through the trees uneventfully before coming upon a different kind of trail marker: the corpse of a Word Bearers apostle impaled upon the sharped branch of one of the great trees. The marine's armor was stained maroon with old blood and covered in a series of deep gouges all arranged in patterns of three.
"Stay on alert. It seems we've found the handiwork of this 'dark spirit' the Word Bearers were so afraid of." Mortartion said.
They continued on through the forest, and the corpses of Word Bearers appeared in increasing numbers as they approached the infernal chapel where Lorgar was sequestered. Some were impaled as the first one, while others lay dismembered on the ground and others still had their dismembered limbs strung up amongst the black branches of the great trees. All of them bore the same claw marks across their armor, leading Mortarion to begin to understand why the Word Bearers had been so fearful of this place.
But why would Lorgar choose to meditate in such a perilous location? Mortarion thought. He never quite had his wits about him thanks to his ridiculous religious practices… but surely, he would know better than this.
Suddenly they came across the disemboweled carcass of a Word Bearers terminator, lying dead in the center of the path. While the corpse itself was unremarkable, what stood out to the Primarch was the small black bird pecking at the exposed and rotting flesh of the dead marine. The small raven dug its beak into the grey-pink flesh, tearing out small pieces and swallowing them. The bird turned to Mortarion and looked at him with its small, beady eyes, fidgeting and tilting its head while preening its feathers. It opened its beak and squawked loudly, outstretching its wings before flying away in a flurry of feathers. Mortarion watched as the bird disappeared above the forest canopy with eyes squinted in suspicion. As they continued along the path, the sound of squawking intensified and multiplied as the number of birds seemed to grow.
The Death Guard reached a clearing in the woods, and ahead was a steep hill atop which sat a great fortress-monastery of cyclopean black stone. The black ravens crowded the branches of the visible trees and circled the air above the temple, the sound of their shrieking cries reaching cacophonous levels. The blood-red sky bore down on them even more intensely here, giving everything around them a scarlet tint. Mortarion looked around, scanning the tree line for any hidden threats but detected none. The clearing was empty of bodies, meaning that whatever had killed the Word Bearers either didn't leave the forest or, more likely, had simply dragged all of them there as an intimidation tactic for any who dared to come near the temple. Just as they emerged from the trees into the large clearing, Mortarion saw a dark shadow move across his peripheral vision. It was impossibly fast, and had he not already been on alert he may have even ignored it as a trick of his imagination. He turned around to find that, to the shock of the plague marine squad, one of their ranks had disappeared. Mortarion swiveled his head for any sight of the lost marine, until his eyes fell upon the soldier's shredded remains impaled upon one of the branches just as the Word Bearers had been, covered in a number of ravens ripping and tearing at his freshly slain corpse. Mortarion began to unsheathe his scythe, however before he was finished the shadow struck again and spirited away another of the plague marines. Mortarion gripped the hilt of his scythe tightly, his eyes darting back and forth as he searched for the unseen attacker.
The birds were becoming louder and more raucous, flapping their wings and crying out as if encouraging the slaughter. The sky grew more crowded with black birds circling overhead, abandoning their vigil over the temple to focus on the Primarch and his escort. The squawking and crying of the bird grated against Mortarion's rotted ears, each mocking shriek raising his anger and frustration even further. From the corner of his eye, he faintly detected movement in the darkness of the trees. In the blink of an eye, he cleaved his scythe to the side, the shockwave of his strike slicing clean through several layers of tree trunks and causing them to be felled all at once. The corvids' cries rose to an uproar, becoming even more manic than before. The shape seemed to appear and disappear out of sight, darting through the trees faster than Mortarion could follow.
"Commander." Mortarion said.
"Yes, my lord?" The Deathshroud replied.
"Duck."
The Deathshroud fell to the ground, the claws of the amorphous shadow scraping against the edge of his armor. Time moved slowly for Mortarion as his combat reflexes kicked in, the hidden attacker appearing as little more than a smear of darkness due to its speed. Luckily, Mortarion's daemonically enhanced strength allowed him to move far more quickly than his bulky, rotten frame would let on. The edge of his greatscythe was already moving by the time the Deathshroud began to dodge, and its pointed tip was aimed squarely at the center of the black shadow. The moment the blade's serrated edge touched the shadow it exploded into a frantic cloud of swarming ravens, flying out in all directions.
The birds in the trees all took flight, joining their sky-borne brethren in a column of dark shapes swirling around the Death Guard until they nearly blotted out the scarlet sky. Mortarion and his forces fired into the wall of ravens, the holes created by their shots quickly being re-filled by the swarm. The shadowy cyclone coalesced above them into an immense, writhing sphere, unfurling into a stream that curled around and dove straight towards the marines. The birds dodged Mortarion's scythe strikes, moving instead to strike one of the Deathshroud. Ravens attacked the terminator from all angles, burrowing underneath his armor until the marine exploded in a shower of gore and black feathers. No matter how many birds the marines and Mortarion killed, the swarm seemed to only grow larger, shredding armor and tearing flesh with every passing second. Only Mortarion was able to fend off the attacking birds successfully, cleaving apart dozens with each movement of his scythe. One of the plague marines fell to the ground, his wounds simply too severe for the soldier to continue fighting. One of his comrades soon followed, and within seconds the entire squad had been wiped out. The Deathshroud fared mildly better, however even their inhuman stamina was no match for the thousands of cuts inflicted by the dark swarm. Soon, all that remained was a single terminator and Mortarion himself.
The swarm abated, pulling back and convalescing into a single shape. The individual members of the flock fused together into a single, inky cloud of black shadow, its edges wispy and undefined. The shape began to transform, molding itself into a vaguely avian outline of immense size. Without warning the giant bird dropped out of the sky and soared just above the ground, dragging its claws across the earth at supersonic speeds. Mortarion managed to dodge out of the hurtling beast's trajectory just in time, although his last remaining Deathshroud was not so lucky. The long talons of the winged shadow pierced the terminator's chest, lifting the Deathshroud up and climbing high into the air. Just as quickly as it had risen, the bird shot down and slammed the shredded remains of the terminator into paste before Mortarion, shattering the earth with its impact. The swirling shadow began to rise from the ground, unfurling its inky wings to reveal itself in all its unholy might. It had three burning ruby eyes, shining like lascannons upon its long beak. Within its maw were rows of sharpened teeth, dripping with an inky black substance that seemed to dissolve into the air like the rest of the shadowy aura surrounding the creature. It stood upon thin, scaly legs and avian claws armed with immense, curled talons. Beneath its wide, shadow-dripping wingspan were long, feathered arms tipped with daemonic claws poised for attack. The corvid beast let out a terrible shriek, shaking the leaves off of the trees with its cry. Mortarion readied his scythe.
"Looks like I have to do everything around here." He said.
The shadow monster shot forth, and the sky split when its talons collided with the edge of Mortarion's scythe.