*Wait!' cries Captain Thayer, reaching out to the s.p.a.ce Marine, but he finds himself barged unceremoniously to one side as the warrior ploughs through the crowds towards the still-growing monster.

The captain scrambles back to his feet and manages to climb onto the pedestal of a broken statue. As he looks out over the heaving throng, he catches other glimpses of silver, appearing at various points in the vast, shifting darkness. It seems almost as though they are arriving from nowhere. As Thayer watches in disbelief seven of the glittering figures materialise from the shadows and begin charging towards the mountain of thrashing limbs.

Thayer looks back at the door and sees that he has a chance to escape, but he finds he cannot leave. The scene unfolding before him is like a tale from the oldest legends: a giant creature from the warp, surrounded by glittering, armour-clad knights. The captain forgets his terror for a moment as he watches the s.p.a.ce Marines charge towards the thing that is devouring the ship.

The monster lifts its mountainous pile of limbs, severing a cl.u.s.ter of fuel pipes and spilling gouts of blue flame across the hangar. Whole swathes of the crowd ignite and their agonised shadows begin to dance and writhe across the walls.

The fire does not slow the s.p.a.ce Marines and as they race towards the writhing monster they raise their halberds with mute synchronicity, levelling the pulsing blades at its huge, arachnid limbs.

At the last minute, Captain Thayer looks away, unwilling to watch the creature feed on its silver-clad attackers. Then, rather than the sounds of messy consumption he was expecting, he hears a new sound: a thin, piercing whistle, so loud he has to clamp his hands over his ears. He looks back and sees to his amazement that the vile creature is rearing up in pain. The s.p.a.ce Marines' weapons are embedded deep in its legs and their power has spread across its flesh in a network of glittering, sapphire veins.

As he follows the lines of light, Thayer sees that they are racing towards the warp creature's featureless, sack-like head. The captain howls in fear, realising too late that he has made a terrible mistake: in his excitement he has looked directly at the thing. His mind recoils from the insanity of it. *Mercy,' he groans, sliding down the pedestal onto the trembling floor. No mercy is forthcoming as his thoughts race down avenues best left unexplored. In a fraction of a second the captain perceives all the dreadful, pitiless lunacy of the universe. *Mercy, mercy, mercy,' he repeats as screaming, burning figures barge past him. His shattered thoughts present him with a variety of disturbing images, one of which might be reality. He sees the monster lash out with its countless limbs, sending a s.p.a.ce Marine spinning through the air like a child's toy. The warrior flies up towards the gloomy, vaulted ceiling of the hangar, then plummets back down into the h.e.l.lish inferno.

The vast hangar is quickly filling with flames and the temperature is rocketing. As Captain Thayer lies gibbering against the pedestal, the rows of faces racing past him begin to shimmer in the heat. Then he starts to question even that; is it really the heat making their features undulate and slide? There is something fierce and b.e.s.t.i.a.l about their expressions.

He looks back at the warp being and sees that, incredibly, most of the s.p.a.ce Marines are still attacking it. The light spreading from their halberds is blazing even brighter and the monster is recoiling in pain. Captain Thayer realises that the thin squealing sound is coming from its yellow, membranous head. *Mercy,' he says again, but this time his tone is one of awed respect. Even from the depths of his growing madness, he realises the immensity of what they are doing. How can they be so calm, he wonders, in the face of such a mind-bending horror?

As the creature attempts to wrench its limbs free, its impossible bulk topples back against the wall of the chamber. The whole edifice teeters and as the wall gives way, so does a large section of the ceiling. Marble saints topple from the shadows: gleaming goliaths the size of houses explode as they slam down on the raging fires.

Still the s.p.a.ce Marines endure, climbing, mountaineer-like, up the monster's heaving bulk. Another one dies, pulped against the wall as a twitching, kilometre-long limb breaks free. But the rest simply thrust their blades deeper. The blue light is now so bright that the warp creature's innards are visible a pulsing like the flames below.

Captain Thayer realises that however hard they fight, the s.p.a.ce Marines have no hope. With every second that pa.s.ses, the monster continues to grow in size and fury. Thayer starts to laugh. It is a wild, shrill sound, almost in tune with the monster's screams. As he laughs he places the muzzle of his pistol against his head and makes a final plea for mercy.

CHAPTER TWELVE.

As they enter the catacombs, Frater Gortyn plucks a torch from the walls and waves it around his head, pushing back the darkness to reveal a jumbled mess of broken headstones and shattered sarcophagi.

*These old stones mark the heroism of a glorious age,' he says, dusting down one of the inscriptions with his silk-clad hand.

Sergeant Halser's eyes glitter hungrily in the flames. The names carved into the stones have long since faded, but their power still hangs heavy in the air. This is clearly the resting place of legendary figures. Rows of alcoves lead off into the darkness, each one filled with tall, pillared tombs, grandiose winged sculptures and faded murals. *Who were these champions?' he asks, taking another torch from the wall and holding it over a tomb.

The gaunt-faced pilgrim still has the same, inane grin frozen on his face, even as he discusses the dead. *Forgotten heroes, Sergeant Halser, of the highest order. These men and women fought beside the Holy Emperor as He carved a great empire in the stars. Only the bravest and most loyal of His servants were interred in the sacred earth of Ilissus. For many decades they were brought here, as defiant and n.o.ble in death as they were in life. As the Emperor's wars grew in ambition, the number of casualties grew too. But we cared for them all, placing their remains in the most beautiful caskets we could build and storing the spoils of their crusade in our most secret reliquaries.'

Brother-Librarian Comus is still hesitating at the entrance, but Frater Gortyn waves him in and hurries off down the aisles of gloomy alcoves. *But the Emperor never forgot his loyal comrades. He visited Ilissus several times in his star chariot. Many records from those days are still held in the scriptoria. They describe how the Emperor did not just come here to pay His respects, He came seeking solace and even advice when He was most sorely pressed. The Zeuxis chamber contains several portraits of Him, kneeling at these very tombs.'

Most of the Relictors look around in awe, shocked by the idea that they might be treading in the Emperor's footsteps, but Halser rushes after the pilgrims, lifting his torch higher. *Then the scriptorium does still exist!'

Frater Gortyn turns his grin back on the sergeant. *The Pilgrims of the Sacred Light have endured on Ilissus since the days of the Holy Emperor, guarding and waiting. When the Emperor's fallen heroes came to us laden with strange, dangerous treasures, we swore to protect not just their memories, but their power. Our centuries of vigilance are recorded in great detail.' His smile falters. *There were many dark years, of course.' He waves at the dozens of smaller pa.s.sageways that lead off from the main artery of the catacombs. *The Emperor's visits ceased without explanation and we were forced to hide ourselves down here as the Great Enemy ran unchallenged, razing our forests and farms to the ground.' Then the smile returns to his face and he makes the strange gesture again, flicking his fingers away from the crystal. *But finally the Emperor sent us a sign that He still lived. A star fell from the sky. And that star was His prophet, Astraeus.'

As the Relictors squeeze their armoured bulk past the mounds of shattered stone, the smaller, hooded shape of Pylcrafte hurries after them, eyeing the group of pilgrims with undisguised hate. *And just how did you survive all those "dark years"?' He points his cane at the ceiling. *Hiding under a few rocks is not usually enough to avoid the snares of the Ruinous Powers.'

The bile in Pylcrafte's voice is obvious to everyone except Frater Gortyn, who smiles cheerfully back at him. *You are quite right, friend. Over the years the black knights hunted us down without mercy. Our numbers dwindled and many priceless treasures had to be destroyed, lest they fall into the enemy's hands.'

Pylcrafte shakes his head, but keeps his optical cables fixed on the grinning pilgrim. *And I suppose you had no option but to lay your hands on those "priceless treasures" and turn them against your foes? After all, why would you let your fraternity fail, when you had access to items of unnatural power?' He shivers in disgust. *Whatever the source of that power might be.'

Frater Gortyn stumbles to a halt and shakes his head in speechless denial. The smile drops from his face.

One of the other pilgrims steps from the shadows, looking equally dismayed. *Oh, no. You don't understand. We cannot use the objects left in our care. They are for the hands of the Emperor alone.' He shrugs. *And the hands of His prophet, of course.'

Pylcrafte sounds unconvinced, and Sergeant Halser makes no move to silence him, keen to hear more detail about the relics left in the scriptorium. *So how have you survived?' demands Pycrafte in a peevish tone. *It is a matter of Imperial record that the Black Legion landed on Ilissus in large numbers. How can your order have survived intact, unless...' He draws himself erect and places a hand on the medallion swinging beneath his hood. *Unless you are in league with them?'

Frater Gortyn steps closer to Pylcrafte, oblivious to the revulsion his nearness induces in Inquisitor Mortmain's acolyte. Despite his lack of eyes, the pilgrim reaches unerringly for Pylcrafte's arm and grips it with his silk-bound fingers. *Some of us fell, it is true. Mephitis and Axum and many other places failed in their duty, overcome by fear, but who can really blame them?'

Pylcrafte s.n.a.t.c.hes his arm free and jabs a finger at the pilgrim. *You do not even condemn their heresy, then?' The cables under his hood flick out like snakes and focus on the s.p.a.ce Marines towering over them. *Did you hear that? He who excuses heresy must himself be a brother of the d.a.m.ned. He just said that they have survived down here for years, but we know that in recent times the planet has been utterly overrun by Chaos. How can they have survived? Answer me that?'

He draws his laspistol and levels it at Frater Gortyn. His voice is verging on a scream. *There is blatant heresy here, Sergeant Halser. Are you really willing to let it go unpunished? By the Emperor a they don't even have eyes! How do they see? Will you really endorse such repugnant sin?'

*Brother Volter,' says the sergeant, with a nod to one of his men.

As the s.p.a.ce Marine steps towards him, Pylcrafte backs away, cursing, and holsters his gun.

Halser's jaw ripples with muscle as he glares at the hooded figure. Then he turns to Frater Gortyn. *How did you survive?'

The pilgrim steps away from Pylcrafte and raises his hands in a gesture of bemused innocence. *Astraeus, of course.' He frowns at the sergeant. *If you have travelled from the heavenly bodies surely you must know of the Emperor's prophet? Have you never heard of Astraeus?'

Halser shakes his head and looks back at Comus. *Does the name mean anything to you? Is it recorded in the libellus?'

The Librarian is clutching his temples again, clearly in pain, but he manages to shake his head.

*Well,' exclaims Frater Gortyn, grinning at his fellow pilgrims. *It looks like we are going to spread a lot of happiness this day!'

They grin back at him, nodding eagerly.

*The prophet is both father and shield,' he continues, turning his crystal star in the direction of Pylcrafte. *He is one with Ilissus. He is one with the earth and the air. He blinds the eyes that would wish us harm.'

*And this prophet,' asks Halser, *is he here somewhere? We have very little time.'

*Of course!' beams Frater Gortyn. *He knows everything about you. He's dying to meet you. He's waiting for you in the City of Stars.'

CHAPTER THIRTEEN.

Inquisitor Mortmain stands in the doorway for a moment, silhouetted by the inferno raging behind him. His leather cloak is lined with smoke and his shaven head is caked in blood. His eyes are as flat and lifeless as those of a corpse.

*My lord?' cries a young Naval officer, rushing towards him. *Are you injured?'

Mortmain gives no reply as he slams the door shut. He turns, aims his laspistol at the lock and fires repeatedly, turning the mechanism into a molten lump. Then he stands there in silence, staring at the door as the officer watches him anxiously.

*The ship is lost,' he announces after a few moments, without turning to face the officer.

The officer laughs nervously and looks around. They are standing at the end of a long antechamber that leads onto the bridge of the Domitus. Ranks of limbless, hooded servitors line the walls, grafted onto flickering control panels. Their pallid, slack-jawed faces show no sign of recognition but the officer hurries to the inquisitor's side and lowers his voice. *Perhaps you should speak to the captain, I'm sure he can rea.s.sure you.'

Mortmain finally looks at the officer and sees that he is little more than a boy. The inquisitor shakes his head sadly, then says: *Lead me to him, son.'

Captain Severinus is a ruddy-faced bear of a man, with a wispy crown of red hair and a barrel chest that his braided jacket cannot quite hold in check. His reply is a deep bellow of laughter. *I do not think we should write off an Imperial battleship quite so easily, Inquisitor Mortmain. Do you realise what kind of manpower we have on board?'

Mortmain gives no reply, and the captain looks to his officers for an explanation. They look as confused as he does.

*What have you seen, Inquisitor Mortmain?' The captain cannot entirely hide the fear in his voice. Whole sections of his ship are imploding without any sane explanation. The only information that has made its way back to him is the kind of lunatic gibberish that he would rather not consider.

The inquisitor looks at the hunched rows of servitors. *We don't have much time. We will have to begin sooner than I thought.' He grabs the captain by the arm and drags him back to his chair. *Give the order to drop into orbit. Alert the rest of the fleet. We must prepare the missiles for launch.'

Captain Severinus wrenches his arm free and his cheeks shift from red to purple. *I'm not a navvy!' he roars, drawing back his shoulders. *This is my ship, Inquisitor Mortmain. Show some b.l.o.o.d.y respect! I give the orders on this bridge. Even the Ordo Malleus can manage a littlea'

Inquisitor Mortmain rounds on him with a snarl. *We're going to die.' His voice is low and dangerous. *Very soon.'

The captain shakes his head and opens his mouth to reply, but the inquisitor is too fast.

*Listen to me!' he roars. *We are going to die. All of us. But if you can shut up and listen for a second we may still be able to save the rest of the sector.'

Captain Severinus's jaw drops. He has never heard the inquisitor's voice raised before.

When he is sure he has the captain's full attention, Mortmain gives a nod of satisfaction. *Good,' he says, in a softer voice.

*What is it? What has happened?' asks the young officer.

Mortmain runs a hand over his blistered scalp and looks back at the door. The sounds of destruction are growing louder with every second that pa.s.ses. Deep, rumbling explosions rock through the hull and the rattle of gunfire rings up through the mesh floor. It feels as though the ship is already in its death throes. *The immaterium has taken physical form. And it is hungry.'

*What do you mean?' The captain regains a little of his anger. *We left warp s.p.a.ce weeks ago. How could such a thing happen?'

Mortmain looks at the floor for a moment, unsure how to reply. *There is no time to explain, captain. It is enough for you to understand that we are carrying a daemon. A daemon. It is making its way towards us, but it wants more than just our souls. I believe it will attempt to stop the Exterminatus.'

Captain Severinus drops heavily into his chair, looking dazed. *A daemon from the warp?' He clutches his head. *How could that happen?'

*What interest would such a thing have in Ilissus?' asks one of the other officers, his face draining of colour. *The planet has already fallen to the Ruinous Powers.'

Mortmain looks out at the vaporous planet. *The daemon knows of our mission. It knows the strange nature of the weather that has been spreading from Ilissus. I believe it will attempt to save the planet and then feed the disturbance with its own life-force. No one entirely understands what is happening down there, but one thing is clear: if the disturbance is not curtailed immediately, we could be looking at a catastrophe of unimaginable proportions.' He taps the tube of parchment clasped to his belt. *All these pretty signatures will be meaningless if the daemon manages to stoke whatever strange fire is burning down there. The temporal disturbances that have been plaguing this system could spread to the whole sector.' He looks at the officer. *Even I cannot predict what would happen then.' His voice drops even lower. *We must destroy the planet now, while our souls are still intact.'

Captain Severinus lifts his head from his hands. *But we've just sent men down there. And not just any men: Adeptus Astartes.' His jabs a finger at the viewports. *One of them is your friend!'

Mortmain nods and closes his eyes for a second, but gives no other reply.

Severinus shakes his head. *There has to be a way to stop this thing. Even a daemon must have a weakness. Surely the Ordo Malleus has faced such things before?' He narrows his eyes. *I hear that you have s.p.a.ce Marines in your own entourage, Inquisitor Mortmain. Adeptus Astartes who travel with an inquisitor? What horrors must they have seen? Surely they can do something to help?'

Mortmain scowls. The captain has been prying into things that do not concern him. Then he shrugs. What difference does it make now? He waves his hand at the door. *If you listen carefully, Captain Severinus, you can hear them dying.'

They all listen to the distant sounds of battle, the wailing of sirens and the groaning of the damaged ship.

Mortmain closes his eyes. *Their heroism is beyond reckoning, but it will not be enough.'

The captain's cheeks flush darker. He places a hand on the hilt of his sabre and glares at Mortmain. *And what if you're wrong? What if it's our close proximity to Ilissus that's causing the problems? If we enter attack formation we might open ourselves up to even greater danger. What ifa'

Inquisitor Mortmain moves with unnerving speed. Before the captain can finish his sentence he steps forwards, draws his laspistol and clubs him to the ground.

There is a loud thud as Captain Severinus slams onto the floor.

Mortmain calmly wipes a splash of blood from his cheek and looks around the circle of officers. His expression is a sharp contrast to their looks of shocked disbelief. *I apologise for my rough manners, gentlemen,' he says, holstering his pistol, *but we really don't have time for a debate. Does anyone else wish to question my authority?'

The officers shake their heads and back away, looking anxiously at the pool of blood spreading around their captain's head.

*See to him,' mutters the inquisitor, turning to the young officer.

As the youth kneels to examine the captain's injury, Mortmain addresses the others. *Inform the rest of Fleet Sanctus. Prepare for bombardment.'

CHAPTER FOURTEEN.

As they leave the catacombs Frater Gortyn steps proudly to one side so that the Relictors can enjoy the view.

Sergeant Halser is the first to emerge, taking a deep, grateful breath of evening air as he steps out onto a rocky promontory. He immediately staggers back and mutters an oath, stunned by the unexpected scene spread out before him. They have come out at one end of a long, steep-sided valley. The strange, convoluted mountains rear up on either side of them, dripping with scarlet fire, robed by the setting sun. It is not the sheer-sided peaks that cause Sergeant Halser to gasp, though. At the heart of the hidden valley lies a beautiful, glittering secret.

*Welcome to Madrepore,' sighs Frater Gortyn, his voice trembling. *The City of Stars.'

As the other Relictors climb up out of the shadows, they are as stunned as their sergeant. Madrepore is a small, walled city, designed in the shape of a five-pointed star and even in the fading light it sparkles like a polished jewel. The towering walls are as organic and coral-like as their surroundings, but they are also bedecked with countless shimmering lights. The whole structure has a shifting, pearlescent quality quite unlike anything the s.p.a.ce Marines have ever seen. It seems as though a portion of the heavens has fallen to earth and is slumbering amongst the mountains of Ilissus.

Halser steps further onto the ledge. *What is this place?' He shakes his head. *That's not Imperial architecture.' He grabs the hilt of his chainsword and glares at the grinning pilgrims. *Where have you brought us? Is this a xenos city?'

*Far from it. This is our home.' The pilgrim laughs and points to a single tower that reaches even higher than the city's outer walls. *Astraeus lifted these stones from beneath the ground with nothing but the power of prayer. His father, the Emperor of Terra, bequeathed him the merest scintilla of his eternal light, but that was enough to create this blessed, beautiful haven.' He waves at the surrounding mountains. *For decades we hid ourselves down here in this valley, guarding the ruins of the old scriptoria in the knowledge that one day, inevitably, the Great Enemy would find us. But then, when the prophet came, his prayers did more than build us a city a they also shrouded the valley from sight. n.o.body can see over these peaks. If Astraeus had not willed it, even you could never have found this place.'

Sergeant Halser looks back at Brother-Librarian Comus with a raised eyebrow.

Comus nods in reply but is too weak to make comment. He has clasped the libellus back onto his belt, but there is no sign of his pain lessening. If not for the firm grip of Brother Volter, he would not have made it through the catacombs.

Halser looks down at the sparkling city walls. *What are the lights in the rock?'

Frater Gortyn's smile becomes a giggle and he does not seem to have heard the question. *The prophet's vision goes far beyond mortal sight. His mind is alive with countless images. He sees the movements of the heavens and the changing of the weather. In fact, he is the weather.' Gortyn waves at the tumultuous clouds, merging seamlessly with the spirals of rock that cover the landscape. *What you see here is only a fraction of his power. The spirit of the Immortal Emperor has been harnessed and refracted through the prophet's flesh. The towers you see out there are the fingers of Astraeus, reaching up and dragging us to salvation.'