I do not own the Warhammer 40000 universe nor any of its characters. They belong to Games Workshop.

Inspired by the Dornian Heresy, by Aurelius Rex.

AT THE HOLLOW MOUNTAIN

While Terra is home to many halls of power whose influence stretches across the entire galaxy, there is no building on the entire Throneworld more vital to the Imperium than the Chamber of the Astronomican. Carved from what once was Terra's greatest mountain, it is there that thousands of psykers are united in holy communion, casting the light of the Astronomican across the galaxy in order to make Warp travel possible in the Imperium. For ten thousand years, that light was directed by the Emperor's undying will. But with His demise and Magnus' succession, the Beacon's strength wanes, and the Dark Prince sends one of his servants to extinguish it forever …

We see the Forbidden Fortress, the Hollow Mountain – the torch that casts the light of the Astronomican into the Warp. We look from within the chamber where uncounted millions have given their life and soul to the Beacon. They are with us, the echoes of these martyrs. Men, women and children – so very many, brother. We see through their eyes, we feel their pain. Everything they were burned away to fuel the fire, but the memory of their pain imprints the very bones of the earth here.

We see Leops Franck, the Master of the Astronomican, slumped in his throne at the center of the Beacon. He could not bear our father's death, the brief instant where no one's will held the reins. For that single moment, it was he who had to direct the power lest it consumes the entire world. He did his duty to the end, even as terror and annihilation claimed him. Naught remains of his soul now, and his body slowly turns to dust as the power lingering within it consumes it. Another High Lord slain, another soul lost to the endless demands of duty. But the burning cannot stop. It must not stop.

We see Kyriss. Kyriss the Perverse, Kyriss the bringer of ruin, Kyriss who whispered honeyed lies into the Angel's ear. It is reborn now through the service of ancient bloodlines and the treachery of innocence. Those who preserved their lines and kept their true faith secret for millennia are now rewarded by the annihilation of their selves, reduced to bloodthirsty nightmares to unleash upon Terra's halls of power. Ever has Kyriss grown strong on the betrayal of trust, on the shattering of bonds, for it was born from the moment the first Eldar betrayed someone they loved purely for the thrill of it.

It has been on Terra before, when our brothers brought madness and ruin to this world. Look to the records that speak of the Ninth, and you will find its monstrous footprint there. It lost then, and it will lose now, for heroes gather to stand against it now as they did then.

From orbit came a ship, dancing through Terra's burning skies. It was small, a droplet of metal going down, down, down, leaving behind the Gift of Eden upon which its dreadful passenger had been born. Behind the transport, the pleasure station was falling, the engines that maintained its delicate orbit destroyed by the maddened mutants rampaging across its corridors. Had this happened on any other day, a thousand guns would have blasted the station into its component particles – but this was Light's End. The Tear of Nightmares was open, and the spears of the Dark Prince had already struck the Throneworld to devastating effect.

A few defense platforms managed to fire nonetheless, shattering the reinforced dome beneath which Imperial nobles had gathered for three centuries. Their efforts meant that, instead of a single meteor striking Terra, several smaller ones hit in quick succession. Whether the damage this inflicted was any lesser than the impact of the full station would have been was a matter for the tech-priests of the Logi to calculate later.

There, amidst the devastation, the transport landed – though crashed would be more appropriate a term. A lone figure emerged from the wreck, unfolding from confines that were far too small to contain its bulk. As horrible as it was beautiful, the Exalted Keeper of Secrets Kyriss walked upon Terra's surface once more, the broken stone beneath its feet sizzling at its infernal presence.

The vampiric children of tainted nobility who had, against all odds, survived the Gift of Eden's descent, shrieked as the Keeper of Secrets strode forth. Nearby cultists, Neverborn, Laers and Tithed Ones rallied to the Greater Daemon, drawn by its dark majesty like moths to the flame. Soon Kyriss walked at the head of a host of thousands of the Lost and the Damned, crushing any pockets of resistance they encountered on their way north from the crash site of the Gift of Eden.

From the Tower of Hegemon, Omegon had seen the threat to the Astronomican, and dispatched forces to reinforce the Hollow Mountain's defences. From the vast Imperial armies called to Terra for the celebrations and now turned to desperate guerilla actions against the Slaaneshi hordes, the Primarch had located a Company of Sons of Horus between the Tower and the Mountain. The reinforcements that Omegon sent to the Forbidden Fortress met with these Cthonian warriors, and quickly rallied them to their cause – for all Space Marines were aware of the Astronomican's importance to the Imperium.

Other such task forces were dispatched by the Lord of the Hydra, with members of the Chosen of Magnus accompanying each one, both for their experience in fighting the denizens of the Warp and because their Rubric-shielded minds were among the few reliable means of communications left.

Moving quickly amidst the desolation of the Angel War, the first of these groups managed to reach the base of the Hollow Mountain ahead of the Greater Daemon. The defenses of the Astronomican, vast batteries of guns that could scour armies from existence in seconds, were silent. Despite the wards that shielded them from the errant thoughts of the Astronomican's psykers, the brains of the servitors slaved to their controls had fried when the Tear of Nightmares had opened. Violent battles raged within, as its guards fought against psykers whose minds had been destroyed by the great Warp anomaly.

The Alpha Legion had anticipated that some issue may arise in the Astronomican with the Emperor's ascension to godhood, and Omegon had stationed several squads of his best warriors in the Hollow Mountain – without, it should be said, asking for the Master of the Astronomican's permission. When Light's End struck and anarchy descended, these warriors had emerged from their hiding places, providing support to the beleaguered guards.

The reinforcements from the Tower of Hegemon landed on one of the platforms that delivered the many supplies needed to keep the Fortress functioning. Moving quickly, they linked with the remaining guards, purging the area of the Fortress closest to the entrance that was the Greater Daemon's target. There was no time to cleanse the entire structure, and so the Custodes accompanying the strike force used secret command codes to lock down entire sections of the Hollow Mountain, condemning those trapped within along with the mad psykers to a terrible fate.

High Lord Leops Franck, the Master of the Astronomican, had perished when the Emperor had died, throwing the chain of command of the Adeptus Astronomica into disarray. Many of the thousands of psykers linked to the Astronomican had also perished, unable to withstand the wild fluctuations of power brought about by the combined death of the Emperor and the opening of the Tear of Nightmares.

The Sons of Horus commander, Deradaeddon Nemo, rallied the mortal defenders, folding them under his command. A veteran from a hundred warzones, the commander was well used to leading other Imperial units, and he quickly arranged them into a defensive formation. A few of the automated defenses were jury-rigged to respond to manual commands rather than their dead servitor crews.

So it was that Ahzek Ahriman and Ephrael Stern, accompanied by several squads of Custodes, Alpha Legionaries, the five hundred warriors of the 52nd Company of the Sixteenth Legion, and the remaining guards of the Forbidden Fortress, came to stand against Kyriss and its horde. The wounds Ahriman had sustained during his final battle at his Primarch's side in the Haydes had yet to completely heal, but the expertise of the Mechanicus combined with his biomantic powers had returned him to a level of health where he could fight once more.

We see Ahzek Ahriman. He carries the burden of his brothers' death upon him. The shadow of Ormuhzd follows him wherever he goes, a guilt that will never leaves him. He could not save his twin – he could not save Prospero – he could not save his Legion. That is the litany of his guilt, one that weighed upon his soul for ten thousand years.

But he did save me. He did, brother. He saved me as he once saved Horus. He brought me back. Yet his guilt remains. Lessened, but not gone. It will never be gone, not completely, because Ahzek will not let it.

Is it pride or wisdom ? He has lost so much. He will lose more, before the end.

We see Ephrael Stern. See how bright she burns in the Sea of Souls ! See how she walks armored in faith ! Here stands one who has seen the truth of a Dark God and did not break from the terrible weight of revelation. Even the death of our father has not shaken her sense of purpose. She is the Daemonifuge, the Bane of Slaanesh, and she exists to bring doom to the slaves of the Dark Prince.

She believes in this with absolute certainty. How long has it been, brother, since either of us believed anything with such purity ? We, who have seen everything we fought for drowned in the tides of History. We, who were born with such power, yet failed to use it to bring about the reality we all dreamt of.

You will despise many aspects of the Imperium as it is now, brother. But there is strength in it too.

The path leading to the Forbidden Fortress, the Road of Blessed Souls, was empty. The last group of transport of tithed psykers to have come up the kilometers-long avenue had detonated halfway to its destination as its cargo of psykers went violently insane and destroyed their wardens and themselves in an uncontrolled burst of Warp energy that had left an immense crater on the Road. The crater was still hot from the psychic fire, but Kyriss didn't care. To it, the pain caused by the heat was merely another sensation to enjoy, another pleasure in the great buffet that was available now that the Anathema was dead. As for those of its minions who perished, their flesh burned by the remnants of the supernatural conflagration … well, their final moments only fuelled its hunger, as did their souls.

Up the Road of Blessed Souls came the Slaaneshi horde, dancing and shrieking and capering and laughing. Already their claws and weapons dripped with gore, the remains of the unfortunate who had been caught in their path as they advanced from the Gift of Eden's crash site. The psychic light of the Astronomican flickered ahead as the psykers within the Hollow Mountain struggled to re-ignite the beacon properly, their efforts shared by the Crimson King on his distant Throne.

With a disdainous gesture, Kyriss sent its minions charging. The first wave was annihilated as the Forbidden Fortress' defenses opened fire, joined by precise bolter fire from the Sons of Horus. Hundreds of cultists died without making any progress. With a snarl, the Keeper of Secrets burrowed its will into the broken minds of the Tithed Ones that had gravitated to its host, and forced the ruined Children of the Emperor forward.

From their ramparts, the defenders watched in horror as they recognized the shape of the Third Legion's heraldry on the broken creatures that leapt forward, howling in mindless torment. Ahriman reached out with his sixth sense, trying to sense if anything remained of the noble sons of Fulgrim within these beasts. With a pained gasp, the former Chief Librarian of the Thousand Sons was forced to retreat, his mind overwhelmed by the raw agony of the Tithed Ones. With a heavy heart, he shook his head, signifying to his allies that the Emperor's Children could not be rescued from their wretched state, save in death.

The defenders opened fire once more, but despite their horrible condition, the Tithed Ones retained their transhuman reflexes, sharpened to a razor-edge by the alterations wrought upon their flesh. Moving like puppets dancing on jerked strings, they leapt away from the lines of concentrated fire. Remnants of tactical instincts, imprinted so deep into their brains by hypno-training that even the Laers' torture hadn't erased them, guided the Tithed Ones through the killing ground and toward the defense towers.

Leaping over the ramparts with monstrous strength, they tore into the heavy guns with warped hands, shredding metal while howling in maddened pain. The Space Marines opened fire – by that point, it had become clear that las-rifles and low-calibre weapons did nothing to the Tithed Ones. But even with bolt shells, each of the Tithed Ones took an inordinate amount of firepower to kill, their souls tethered to their flesh by the Laers' vile sorcery.

By the time Deradaeddon's men had put down the last of the Tithed One vanguard, all of the gun emplacements had been disabled, and the rest of the Slaaneshi host was advancing. Kyriss itself still held back, for the Greater Daemon could sense the presence of Ahriman and Stern. In its arrogance, the creature held nothing but contempt for the threat posed by any mortal – but these were no mere mortals. Ahriman was of the same breed of Thousand Sons that had defeated Kyriss when it had come to Terra during the Siege, and the daemon remembered its defeat at the hands of the sons of Magnus with bitter clarity. Then as now, the Keeper of Secrets had sought to feed on the rich bounty of psychic souls to be found on the Throneworld. But after devouring the spirits of over three thousand psykers, it had been banished by the Thousand Sons, who had taken advantage of its lethargy after such a feast. The pain of that defeat had been exquisite, but by being banished Kyriss had been denied the chance to take part in the Clone and Legions Wars, its privileged bond with the Ninth Legion ending after the reveal of Sanguinius' madness at Iydris and the splintering of the Blood Angels.

Yet for all of Ahriman's power – and the mortal's soul burned bright in the daemon's sight, radiating with the accumulated knowledge of centuries – it was the other Chosen of Magnus that Kyriss truly feared, if daemons can be said to fear anything. Ephrael Stern's presence was a blight to the Neverborn, her very existence an insult to the Dark Prince it served. With the death of the Emperor, one could argue that no other being in existence represented as much of a threat to Slaanesh as Ephrael Stern – at least so long as Ynnead, the Eldar God of the Dead, hadn't fully awakened. Even the loyal Primarchs were not so specifically opposed to Slaanesh, so attuned to his defeat as the Daemonifuge.

The Astronomican had been Kyriss' target in the Angel War, but Stern's presence now took priority. The bonds that had brought Kyriss to Terra compelled it to do whatever was necessary to remove the Daemonifuge from the board, regardless of its own dread at the prospect of facing the Daemonifuge. The Greater Daemon hurled its horde at the ramparts, its infernal will driving them to ignore the volleys of fire raking their ranks as they charged. The Laer soldier-forms among the attackers were unlike anything the Imperials had ever encountered before, but Space Marines are nothing if not adaptable, and they soon learned that they bled and died as easily as any other xenos abomination.

Among the Slaaneshi forces, those mutated nobles who had fallen from the skies along the Gift of Eden were driven toward Ephrael Stern, their bestial minds suddenly consumed by lust for her blood – even though devouring it would surely destroy them. With claws and fangs and monstrous speed they came upon her, jostling each other out of the way as their thirst overcame all other instincts. Even as bolt shells and las-bolts slammed into them they kept charging, and the Daemonifuge strode forth to meet them.

Her eyes blazing with power, Ephrael crashed into the tide of mutants with her sword – the same sword that had held against the might of Sarthorael, the Ever-Watcher – held up high. A corona of white fire spread from her, and those vampires it touched shrieked in agony as their flesh shrivelled and died on their bones. More of their vile kind came – of the hundreds of nobles that had gathered aboard the Gift, dozens had survived the crash – and those met the blade of the Bane of Slaanesh.

She cut through them like a scythe through wheat, and there was nothing they could do against her. Whenever the vampires managed to surround her, her power would flare, and the encirclement would be broken. The Warp-gifted might of the mutants was not enough to overcome the Daemonifuge, and within moments Ephrael emerged from the vampires, her sword running red with their blood, leaving only corpses in her wake.

Meanwhile, under the awed gaze of the other Space Marines, who looked upon a legend straight out of their Legions' annals, Ahzek Ahriman unleashed his psychic might upon the Lost and the Damned. Lightning and fire incinerated dozens of cultists with every heartbeat, arcs of power crackling on the Thousand Son's ancient armor.

"The Wolves have left their mark on you, lord" shouted Deradaeddon, glancing at Ahriman with approval in his gaze even as he slammed his power hammer into the reptilian face of another monstrous xenos, sending it flying into more of its kind.

"… I wasn't there when Prospero fell," Ahriman said cautiously, unsure whether the commander meant insult or not. The Son of Horus shook his head.

"Not the beasts of Fenris," the Cthonian spat, before a twinkle of humor returned to his gaze. "The old Wolves of the Moon. You fight with the same strength as they do, old man !"

Kyriss saw the display of arcane might, and bade its own sorcerous minions to remove that threat. A trio of Laer psykers, four-legged beasts with six eyes glowing with eldritch fire, tore a path through the defenders, scattering those who stood in their way with bursts of telekine power. Ahriman felt their coming, for what passed for the xenos' souls was like nails being drawn on chalkboard to his sixth sense. With gritted teeth, Ahriman told his allies to step back, and began to battle the three monsters.

In a scene reminiscent of lone hunters of Old Earth facing the packs of predators that had once walked the world, Ahriman fought with his staff, always staying in motion as his senses warned him of the beasts' attempts to attack him from behind. The air around the duelling psykers grew cold, sparks of fell energy leaping from them all as their battle went beyond the physical and into the Warp itself. Nearby combatants heard sounds like laughter echoing in their skulls, and more than one mortal guard fell to the enemy while distracted by the unholy sensation of the Laer beasts' proximity.

While Ahriman was distracted by the Laer sorcerers, Kyriss strode forward, eyes fixed upon Ephrael Stern. The Daemonifuge had sensed the approach of the Greater Daemon long before it had appeared on the horizon, and she met its coming with her sword held firm and determination in her gaze. While around them the Imperial lines met the charge of the Slaaneshi horde, the two champions of opposite powers met.

Ephrael had defeated Keepers of Secrets before : her very essence was aligned toward the destruction of the Dark Prince, and her bloody past was littered with the remnants of her many confrontations with Slaanesh's servants. But she realized in the first exchanges of the duel that Kyriss was mightier than any daemon she had ever encountered before. The Keeper of Secrets was Exalted by its foul deity, and the Tear of Nightmares burning overhead imbued it with greater power still.

Its long, needle-like sword and whip moved with impossible speed, and it was only Ephrael's instincts, sharpened through several lifetimes of battle, that kept her from being struck. With short, controlled bursts from her jump-pack, she dodged the more powerful blows, turning the others aside with her blade. Yet she could not match the strength of Kyriss, and was slowly forced to step back.

Ephrael did not fear death, for she had perished before, only to return to life, driven from the grave by her incomplete destiny. But the prospect of failure – of Kyriss succeeding in claiming the light of the Astronomican, that holy remnant of the God-Emperor's might – that scared her like nothing had in a long, long time.

She did not let that fear consume her, instead drawing strength from it, letting her reinforce her determination not to fail. The aura of daemonslaying power around her intensified steadily even as the duel progressed in Kyriss' favor, but it was not enough to overcome the ruinous blessing that empowered the Exalted daemon.

From where he was battling the Laer sorcerers, Ahriman saw his comrade's plight. He was not alone in that : several Sons of Horus and Alpha Legionaries had tried to come to the Daemonifuge's aid, only to be swat aside by Kyriss with contemptuous ease, their blood added to the flow that had already stained the ground.

During the journey from the Tower of Hegemon to the Hollow Mountain, Ahriman's powers of foresight had granted him a singular truth amidst the madness and confusion that engulfed Sol. He knew, without doubt, that if the Imperium was to survive the Angel War, it would need Ephrael's unique abilities. Yet he could not simply let the Laers kill him in order to inflict a blow to Kyriss – even the fullness of his power might not be enough against the Exalted daemon's strength.

Rising high in the Enumerations, Ahriman considered his options, his thoughts racing behind his helm. When inspiration came, it came with a glimmer of sunlight, passing through the tortured heavens to shine on the broken pieces of a dead Son of Horus' eye-lens.

With a burst of power, Ahriman forced the Laers to briefly withdraw, before falling to one knee, planting his staff into the ground with enough strength to penetrate the rockrete. Head bowed, the Librarian reached toward the greatest source of power nearby – the Astronomican itself. His mind touched the Beacon, and he sensed the presence of his Primarch within it.

In that moment of contact, the Crimson King understood what his son planned, and granted him his help. A flicker of power passed from the Astronomican and into Ahriman – less than a thousandth of the full might of the Beacon, which shone bright enough to be visible across the galaxy. Yet even that fraction of a fraction was almost enough to destroy Ahriman outright, before he could force it out of his own body and into Ephrael's.

The Daemonifuge saw the beam of purest light that emanated from Ahriman's staff. Ahead of that beam ran Ahriman's thoughts, and the Librarian's plan reached Ephrael just in time for her to play her part. She opened herself to the Astronomican's power, focusing it through the lens of her unique soul.

She blazed like a newborn sun, and all who took part in the battle felt righteous fire wash over their souls. Only the Custodes were unaffected, their souls too twisted by the gene-alchemy that had produced them for there to be anything of Slaanesh in their souls. The Space Marines stumbled, fighting against a pain they could not source, and the human defenders cried out in pain.

But the effect was far worse on the Slaaneshi horde. The Laer element simply dropped dead, their tainted souls extinguished by the fire, while the daemons shrieked as it burned them, not only dissolving their corporeal forms but even incinerating their immortal essences. The screams of the mortal cultists were the stuff of nightmares, as their mortal souls were mutilated. The pain of the Slaaneshi taint being excised from their souls was too much to bear, and many perished, their bodies unable to bear the agony. Even those whose flesh endured were left as empty shells, collapsing on the ground without moving, no intelligence left behind their wide, bloodshot eyes.

Nothing remained of the daemon's false majesty. It was a ruined wreck, its pristine skin charred and broken apart. It was bleeding its essence onto the ground it had desecrated. Its weapons laid in shards around it, as unable to bear the power she had channelled as their wielder.

Ephrael forced herself to walk forward, ignoring the pain that permeated her entire body, dragging her sword behind her with each step. She stopped near the daemon's head.

It must have sensed her presence, for one eye opened amidst what was left of its face to look at her. Even now, in its current state, she could feel the hatred of her that burned within … and the fear, too.

"You will die alone," croaked Kyriss. "Your soul will know no peace, no rest, no reward : only oblivion. Doom approaches, Abomination, and you will not escape it."

"I know," replied Ephrael Stern, before extinguishing the essence of the thing that was called Kyriss forever.

In a singular blow, Ephrael and Ahriman had secured victory at the Hollow Mountain. But it had not come without a cost. Many loyal Imperial soldiers had died, and the damage Ahriman and Ephrael had sustained while calling upon the power of the Astronomican made it clear that this was not a card they could play again. The Daemonifuge felt herself drained, and her body was covered in burns, while Ahriman was still kneeling, unmoving. When the Apothecaries of the Sons of Horus rushed to his side, they found him unconscious within his armor, his life signs still present but dangerously weak.

AN : A bit shorter this time. Most chapters of the Angel War are going to be longer, but I felt adding anything to this one would just be padding. The ending may be a bit ... abrupt, but I felt it was appropriate given the rythm of the chapter. What did you think of it ?

The lore for the Hollow Mountain comes mostly from the book The Hollow Mountain, by Chris Wraight. Between the Vault of Terra series that book is from, and the Watchers of the Throne series, I got a lot of lore for Terra and the various factions there. Of course, I have made changes where appropriate. Greatest of these is the fact that it was Perturabo who rebuilt the Imperial Palace rather than Dorn, which is the perfect excuse for any difference between my early descriptions of the Siege of Terra and the revelations of the Siege of Terra series. Boy, did I dodge a bullet with that one.

As I may have mentioned when I wrote The Siege of Terathalion, I really like the concept of Ephrael Stern in canon. I was glad when GW brought her back for Psychic Awakening, though I question the wisdom (both in and out-of universe) of sending her against Necrons. I mean, that woman is a walking, talking, anti-daemon weapon of mass destruction. Surely there are other places in the Imperium where her unique skills would be more useful ? And yes, I am aware that I had her first show up in an arc where the main villains were Tzeentchians, but my point still stands, dammit.

As always, thanks to Jaenera Targaryen for beta-reading this. Next week, the Black Cells. I know a lot of you have been looking forward to that one; hopefully I can deliver something that lives up to your anticipation.

Zahariel out.