The burbled reply makes no sense but, as before, words appear in Palchus's head. *I have more names than I care to remember. Some of them might make sense to you, I suppose, but none of them come close to the truth. My current master calls me Cerbalus. That will suffice for one such as you.'

Palchus latches desperately on to these shreds of information. *Your master? Who is your master? Let me speak with him. As soon as he realises who I am, you will finda'

*Oh, Inquisitor Mortmain knows very well who you are, Palchus van Tol. You are here on his instructions, in fact.'

Despite his agony, Palchus lets out an incredulous laugh. *Mortmain? He would not dare!'

The darkness fills with the sound of sc.r.a.ping metal and a face appears directly in front of Palchus. It is the most terrifying thing the Navigator has ever seen. It must once have belonged to a mortal, living man, but now it is a fleshy casket, straining to contain a writhing, unspeakable horror. The shaven scalp has split in several places, revealing cherry-coloured coils of bone and a faint, shimmering light. The eyes have been scorched away, leaving two blackened pits, with cold blue fire shimmering in their centres. The whole head is torn and misshapen. Only one thing seems to be holding the mangled lump together: a ma.s.s of rusty chains snake in and out of the face, embedded deep in the bones and glinting dully as the mouth opens in a wide, toothless grin. *Oh, you would be surprised at what he dares.'

As the ruptured flesh talks, Palchus sees the reason for the gurgling, moist quality of its voice. The thing's throat is torn and ruined, and its vocal cords are clearly exposed, rattling loosely in a nest of glistening muscle.

Palchus tries to pull back from the monster. Terrible as its appearance is, the thing that really appals him is the voice in his head. The words are so unnatural and malignant he can feel his mind buckling under the strain. This is no mortal creature leaning over him. Something unholy has been bound into the flesh of man. The word *daemon' drifts into his thoughts, but he tries to squash it before madness overwhelms him. *You have to help me,' he gasps.

*Of course I do,' answers the pile of gore and chain. *Mortmain was most concerned for your safety. I cannot leave you in this awkward condition.'

Palchus screams. The monster has placed a hand on the sword in his belly and is tugging it up towards his ribcage.

*Of course,' it continues when the Navigator is quiet again, *I can remove this blade quickly or slowly. I can remove it with care, or less care.'

*What do you want of me?' moans the Navigator, as fresh blood pools in his lap.

*I want you to talk, Palchus, that is all. There is no need for any more unpleasantness. I just need to know why you and your family have come to the Domitus.'

Palchus sees a glimmer of hope, then sighs as he realises the truth of his situation. Strangely, he feels his fear diminishing slightly as he accepts his fate. *You could never let me live. Not now you've told me who your master is.'

There is another rattle of shifting chains and something appears in front of Palchus's face. It is the monster's hand. The fingers are grey and crooked. Gleaming patches of bone are visible beneath lines of jagged, crudely sewn skin. The nails are purple and torn. But it is not the ruined flesh that Palchus notices, it is the long, metal syringe in its grip.

*You're quite wrong,' explains the voice in Palchus's head. *If you would just talk to me, I can wipe away all memory of this encounter. My master has an endearing propensity for mercy, you see. He has specifically requested that I try to help you. You will be found slumped in a gutter, near the slaves' quarters, wounded but alive, and your father will reprimand you for nearly getting yourself killed.' The monster brings the needle closer to Palchus's face so that he can see the liquid dripping from its tip. *All you need to do is explain why you have not left for Terra. What is your family's particular interest in this planet? What links you to Ilissus?'

Palchus's heart begins to race again as he sees that he might be able to survive after all. All he need do is tell the monster about the true cause of Ilissus's storms.

The ravaged face moves closer, sensing that the Navigator is about to speak.

Then Palchus closes his eyes and bites down hard on his lip. To his surprise, he realises that something means more to him than his own precious life. How could he confide in this creature? If the truth about Ilissus were revealed, it would be the end of everything; the end of House van Tol. Their long, distinguished history would be stricken from Imperial records. His glorious lineage would be made worthless. Their properties would be taken and, worst of all, they would be disgraced. The whole of Terra would think that Palchus van Tol was the son of a traitor.

Palchus groans in torment. *I won't tell you anything,' he whispers, unable to believe what he is saying.

The monster leans on the broken sword and sends another bolt of agony through Palchus's stomach. *Are you sure?' A long, rusty knife appears in front of Palchus's face. *I'm more than happy to extract the information from you, but people don't generally enjoy my methods.'

Palchus knows all too well the methods that are likely to be employed by an Inquisitorial lackey, but there is a new sensation mixed with his abject terror: a surety that he cannot let this dreadful being discover the truth. *Some things are worth dying for,' he says quietly.

The thing laughs. *Oh, you won't die, Palchus, I will make sure of that.' The blade presses against the Navigator's trembling throat. *I'm very skilled at my craft. I've had millennia to perfect it.'

Palchus's voice remains oddly calm as he replies. *My father had doubts about coming to the Domitus. He knew it would be disastrous if one of us spoke out of turn. His great fear was that Mortmain might discover the truth.'

*The truth, Palchus? What is the truth?'

Palchus lifts his chin and flares his nostrils. *The truth is that you will get nothing from me. My father foresaw just this kind of eventuality. He made us take precautions.'

The voice in Palchus's head sounds excited, as though trying to contain laughter. *Precautions? What do you mean? What kind ofa'

The sentence goes unfinished as Palchus stamps his right foot on the stone floor with all his strength. The heel of his boot collapses and the explosive charge contained within fills the chamber with blinding light.

The blast is so powerful that the sound travels several kilometres, to a small, dingy chamber, where Palchus's father looks up in alarm.

CHAPTER SEVEN.

The ground splits and churns as Halser races towards the tower. Rocks and bolter sh.e.l.ls rattle against his helmet as he weaves through the enemy blasts. At the foot of the building he launches his power-armoured bulk against a rotten door and it implodes in spectacular fashion, sending him tumbling into a small courtyard. The gunfire grows even more frenzied, but the sergeant turns his tumble into a roll and clatters across the exploding flagstones, sc.r.a.ping to a halt behind a ruined well and raising his bolt pistol to return fire.

He sees a row of Traitor Marines, slumped against the undulating parapet at the top of the strange tower. One of them is carrying a twisted, horned lump of metal. At first Halser cannot recognise it, but as a beam of crackling blue light erupts from the thing's barrel, he realises it is a lascannon.

The well disintegrates and Halser is thrown back across the courtyard. The impact would have killed a mortal man, but the sergeant's power armour softens the blast with a wheeze of hydraulics, allowing him to roll clear, unharmed. As a second Traitor Marine opens fire with an equally grotesque bolt pistol, Halser stands and calmly fires back. Shots ring out from several directions at once, filling the courtyard with light, sound and smoke, and making it impossible to see anything. Power-armoured boots pound back and forth, and metallic voices ring out through the din.

Halser cannot be sure if he has. .h.i.t anything. He tries to aim at the traitor with the lascannon, but the drifting smoke makes it impossible to be sure what he is seeing. Twice he almost fires and then lowers his weapon, afraid of hitting one of his own men. He sees a flash of sparking metal to his left. Comus is jamming his force sword into someone Halser cannot see. There is a screech of grinding metal as the Librarian wrenches his blade free, painting the clouds red as he staggers back and prepares to swing again. *Their shots are wild!' he cries, levelling his sword at the walls. *Someone else is attacking them!'

Someone else? Halser pounds through the smoke to get a better view. As he nears the wall he sees the Chaos Marines lined up on the battlements. Comus is right. All of them are being twisted into bizarre positions: dragged awkwardly to one side or wrenched back over the wall. One of them manages to aim his bolter at Halser, but the shot whines past his head, missing by a metre as the traitor struggles to hang on to his gun.

Halser sprints through the whirling clouds, calling for the squad to advance as he spies a staircase at the foot of the circular wall. As he pounds up the crumbling steps, he sees the reason for the Chaos Marines' odd poses. The clouds of smoke and dust have taken hold of them, wrapping around their misshapen power armour in hazy, shifting columns.

The traitor with the lascannon hefts it round to face the oncoming sergeant, but as he tries to aim he slumps forwards onto his knees, weighed down by the storm.

Halser raises his bolt pistol to fire and pauses in shock. His opponent's leg is now encased in stone, stone that merges seamlessly with the clouds. The limbs of smoke are solidifying as they envelop the Chaos Marines, and morphing into rock. *By the Throne,' gasps Halser, stumbling to a halt. He does not have long to consider the strangeness of the scene. The parapet behind him explodes as another shot goes wide. Halser puts aside his amazement and charges at the beleaguered enemy, jamming his rattling chainsword into the first breastplate he reaches and howling a battle-cry as he disappears in a shower of blood and shredded armour.

The others race up after him, firing calm, precise shots into the heaving ma.s.s. The enemy outnumber them two to one, but there is no contest. As the Relictors blast them apart, the Chaos Marines are wrenched to the ground by vast, animated banks of smoke. As they drop to the flagstones, the smoke forms spines of rock a just like all the other twisted pillars that cover the planet's surface.

For a few minutes the clouds pulse with light as Halser and the others unleash a sustained volley at their howling foes. Then, as it become clear that there are no shots being fired in return, Halser wrenches his rattling chainsword from a limp body and staggers back, raising the b.l.o.o.d.y weapon over his head and turning to face his men.

The gunfire ceases and the Relictors lower their guns, surveying the carnage they have wrought. The walls of the tower are scorched and peppered with holes, and the mangled remains of Chaos Marines lie sprawled across the blood-slick masonry. The Relictors watch in amazement as the columns lose their last shreds of smoke and settle into solid, fixed limbs of rock, enveloping the fallen like a shroud. Horned, groaning helmets adorn the towers like onyx studs in a vast piece of jewellery.

Halser counts the s.p.a.ce Marines gathered on the wall. Only seven have climbed up with him. There is no sign of Comus. He looks down into the courtyard and sees the Librarian's distinctive blue power armour, spread-eagled across the flagstones, surrounded by blood. A man is backing away from him, quickly disappearing into the rolling dust clouds.

The sergeant's pulse pounds in his ears, still charged with bloodl.u.s.t and, without a second thought, he raises his pistol and guns down the receding figure. Only as he climbs down the steps does he see that the fallen man is unarmed and his robes are embroidered with Imperial insignia. Halser curses and turns the man over with his boot. He is still alive but gasping for breath and clutching feebly at the ragged hole in his shoulder. His robes must have originally been white, but they are quickly turning red. The wound looks bad but not fatal and Halser cannot decide whether that is a good or bad thing. The Imperial aquila is emblazoned across the man's chest, but there is something about him that reeks of heresy: both his eyes have been surgically removed, replaced by a two lines of ragged st.i.tching, and a lump of crystal in the shape of a star has been hammered into his forehead.

The man tries to speak, but his words are m.u.f.fled by the blood welling up in his mouth.

Halser crouches down next to him and raises him into a sitting position. *What did you say?'

The wounded man spits a gobbet of blood onto his chest and tries again. *Stay away. Stay away from the prophet,' he gurgles, before being wracked by a terrible cough that dislodges even more blood.

*What?' asks Halser, looking anxiously at the slumped form of Comus, lying a couple of metres away. *What prophet? Who are you talking about?'

*Astraeus,' he gasps, grasping Halser by the shoulders. *You must allow him to complete his trials. You must not ruin his great work.'

*Astraeus?' Halser shakes his head. *What great work?'

The man pulls himself closer and Halser has the unnerving sensation that he is looking at him through the crystal star. As he turns his head from side to side, the failing light refracts through the prism to reveal the grey, knotted brain beneath. *Ilissus is just the beginning. He will purge the entire galaxy.' He turns towards the columns of rock that have enveloped the Chaos Marines. *The elements are now his to command. Soon, the Dark Powers will learn to crawl. The Great Enemy will grovel before him like a cur.' The man's voice grows shrill. *But you must leave Ilissus! You will ruin everythinga'

The man stiffens and lets out a hoa.r.s.e croak as a smouldering hole appears in his chest. Blood fountains from his nose and he slumps back in the sergeant's arms.

Halser drops him and whirls around.

*Filthy idolator,' hisses Pylcrafte, lowering his laspistol and withdrawing his optical cables back into his hood.

Halser leaps to his feet and grabs Inquisitor Mortmain's acolyte by the throat, lifting him up from the ground and slamming him against the shattered wall. *You do not make the decisions here!' His words are so loud that they emerge from his helmet as a distorted blast of noise.

Pylcrafte whines with a mixture of terror and outrage. *This planet is d.a.m.ned! We cannot preserve the life of transgressors! The unsparing severity of the Emperor's wrath must be as swift as aa'

His words end in an explosion of air as Halser slams Pylcrafte onto the ground and aims his pistol at his undulating hood. *Silence!' he howls, his whole body trembling with anger.

Pylcrafte looks up at the circle of s.p.a.ce Marines who have gathered around him. Every one of them has levelled a weapon at him. He mutters under his breath but says nothing more.

Halser looses him and turns away, waving his men over to the fallen Librarian. *Comus,' he says, kneeling down beside him. *Are you shot?'

The Librarian shakes his head and grimaces at the clouds undulating over their heads. *No, I can continue.' He nods at the dead stranger. *I'm starting to understand. The pilgrims never left Ilissus. They never died. They are still here, after all these centuries, but their worship has become confused.' He waves at the clouds again. *The prophet he mentioned is somehow connected to all this. He is the one who has doomed Ilissus.' He clutches his head and groans in pain and confusion. *But he is not a follower of the Ruinous Powers.'

Pylcrafte cannot hold his tongue. *Then why have they defiled a shrine of the Immortal Emperor! What does it matter who their leader is? They are the worst kind ofa'

At a nod from Halser, one of the Relictors steps forwards and clamps a gauntleted hand over Pylcrafte's face.

*Whoever this prophet is, we are very close to him,' continues Comus as he sits up and looks around the courtyard. *Either by chance or his design we have stumbled across one of the routes to his home.' He taps his finger against the small leather-bound book. *According to the libellus, if we find the Zeuxis Scriptorium, we will find the prophet.'

Halser turns to look through the ruined walls of the tower. The sinking sun flashes crimson across the visor of his helmet. *Come nightfall, Mortmain will begin the orbital bombardment. We have less than four hours left to find the scriptorium.' He lowers his voice. *Brother Silvius and the others must manage without us.'

Comus shakes his head as Halser helps him to his feet. *But what really is the use in finding the scriptorium, without any guidance from the Domitus?'

There is a hiss of escaping air as Halser removes his helmet. His brutal features are as red as the sky. *This is our last chance, Comus, don't you understand? Mortmain is our only friend and our enemies are legion. We have to convince them all. We have to show them that our willingness to learn is not heresy, but the Imperium's last hope. We have the courage to go where the other Chapters will not. We are the only ones whoa'

*You do not have to explain any of this to me,' interrupts the Librarian with a look of disbelief. He leads Halser a few paces away from the others and speaks in an urgent whisper. *But how will we get off the planet before Mortmain begins dropping his bombs? If we cannot navigate the clouds, how will we make it off the planet alive? We have four hours left. Perhaps we should return to the gunship and see if we can help the tech-priests?'

A network of throbbing veins spreads across Halser's face and he hisses through gritted teeth. *If we return empty handed we are dead anyway. You remember Captain Asamon's orders: find a weapon powerful enough to cleanse every world in the system. Only if the Inquisition sees our true potential will we have any hope of redemption. If we return now, with nothing, the Relictors are doomed. Every last one of us.' He clutches his hands together as though praying. *But if we can show the strength of our faith, show them that we can wield even the most powerful artefacts, they will have to accept us once more as true servants of the Emperor.' As the sergeant looks around at the shattered tower there is an edge of mania to his voice. *And anyway, what use do you think it would be returning to the gunship?' He waves at the dust clouds. *We have no signal. How would we fly? I doubt we would make ten kilometres before hitting a mountain.'

Comus narrows his eyes, unnerved by the sergeant's odd tone, but he cannot deny his logic. It was a miracle that they managed to land as well as they did. And since then the weather has become even more violent.

Halser pounds his chest armour. *We're not done yet, Comus. I will not allow it!' He stamps one of his boots on the ground, surrounding them both in a cloud of dust. *The Zeuxis Scriptorium is the best known of Ilissus's reliquaries. Think what treasures might be there.' He nods at the bloodstained flagstones. *And you say it is also the source of all this,' he waves at the sky, *sorcery. Why should we head back to the gunship without at least investigating this so-called prophet? I do not doubt he is a charlatan, but who knows what kinds of artefacts he is h.o.a.rding. Alone, without any Imperial support, he has outwitted the Black Legion. Think what that might mean! He has surrounded the whole planet with clouds that turn men to stone. How could he achieve such things? Perhaps by harnessing a forbidden text? Perhaps by uncovering a relic from the days when the Emperor Himself walked here?'

Comus shakes his head. *I don't understand. You want us to head towards the man who has corrupted the whole planet?'

*Why not?' Halser's voice is a ragged snarl. *By the Throne, Comus, can't you see? Maybe we are doomed, but at least we might end our days covered in glory. At least we might put an end to whatever monster is plaguing this wretched planet. And perhaps...' A trace of smile appears on his face. *Perhaps we could find something that truly makes the trip worthwhile.'

The Librarian turns to look at the other s.p.a.ce Marines. They are waiting patiently for orders, as proud and n.o.ble as ever. He sighs and shakes his head. They do not deserve to die in Mortmain's firestorm, but he knows Halser is right: they are doomed anyway. For decades now, the Inquisition has been working towards their destruction. Perhaps this would be a more fitting end: death in battle, at the hands of the Imperium's foes, rather than excommunication and disgrace at the hands of a shadowy cabal. He looks back at the sergeant and falls quiet, unsure what to say. All the options seem black. Then he looks into Halser's eyes and sees how fiercely they are burning. If they have any hope at all, he decides, it is here a in the fury of Sergeant Halser.

Comus takes out the strange little book and attaches another cable to it. The others wait patiently as he prays. Even Pylcrafte ceases his struggles.

*I see another group of towers,' says the Librarian in a hoa.r.s.e voice. *Two kilometres south of this one. They are on the exact location of the underground temple network that once housed various scriptoria, including Zeuxis. If we can make it that far, I believe we will find the man who is in control of Ilissus. What we would do then, I cannot imagine.'

Halser grabs the Librarian by both arms. *Have faith, Comus.' He looks south and watches the spirals of wind, whipping across the desolate landscape. *We will be heroes again, I promise you.'

CHAPTER EIGHT.

Inquisitor Mortmain picks his way through chunks of glowing metal and smouldering flesh. The s.p.a.ce where the interrogation chamber once stood is now a blackened wound. The blast was so fierce that several walls have buckled and fallen, creating an oddly liquid scene: girders, doors and coving lie draped over each other in a surreal slump of melted steel and shattered stone. Mortmain wrinkles his nose in distaste; the air is thick with the smell of charred meat. *Oh, Palchus,' he breathes, kneeling to examine a pile of ash, *What did you do?'

A towering figure watches from the darkness: a hulking giant, clad in gleaming bare ceramite. As he steps closer, the light of Mortmain's torch washes across the giant's power armour, revealing rows of intricate letters engraved into every available s.p.a.ce. When he speaks, his voice peals from his helmet like a sword being drawn. *Does it live?'

The inquisitor lifts a piece of broken chain from the rubble and holds it to his chest, muttering a prayer. *Emperor save us, Justicar Lyctus, it might.' He looks up at the silver-clad s.p.a.ce Marine and shakes his head. *I've been a fool. Cerbalus must have seen this coming. Whatever the Navigator used to do this has broken the wards and bonds we used to bind the daemon. If it managed to latch on to any other living thing, it will now be loose on the Domitus.' He rises and turns to face the s.p.a.ce Marine looming over him, his face utterly drained of colour. *Cerbalus knows everything. It knows that Ilissus is on the verge of plunging the whole sector into madness. If it lives, it will attempt to stop the Exterminatus.'

Justicar Lyctus seems unimpressed by the urgency in Mortmain's voice. His glittering gauntlets remain draped calmly over the hilt of his halberd; if not for the faint light, flickering across the weapon's blade, Lyctus could be mistaken for a statue. *What do you intend to do, inquisitor?' he asks, in the same ringing tones.

Mortmain clutches his shaven scalp in both hands and mutters another curse. *I have no choice.' He looks out through a misshapen viewport at the wraith-like planet below. *I can wait no longer. Baron van Tol's wretched secrets will have to wait. I must destroy Ilissus now.' He looks back at the s.p.a.ce Marine and shakes his head in disbelief. *d.a.m.n it all. If Cerbalus lives, I may already be too late. It will tear the Domitus apart.' He looks past Justicar Lyctus into the shattered remains of the corridor. The light of his torch reveals more glittering, statuesque figures. *You and your squad must do what you can.' Mortmain places a hand on the cover of a metal book, hung around the s.p.a.ce Marine's cuira.s.s. *I will pray for you.'

Lyctus nods and envelops the inquisitor's hand in his own ma.s.sive, silver gauntlet. *If it lives, we will bring it to heel, Inquisitor Mortmain.'

Mortmain shakes his head and withdraws his hand. *No, you will not, justicar. Not this one. Even you will be unable to destroy a horror such as Cerbalus.'

There is a hint of emotion in the s.p.a.ce Marine's reply that is either disbelief or injured pride. *Then what are you asking?'

Mortmain looks up at him. *If Cerbalus is free, we are already dead. But Ilissus must still be destroyed. Too much is at stake.' He looks out at the planet again. *You must buy me whatever time you can. Find Cerbalus and throw yourself against it with all the fury you can muster. You cannot win against such a being, but you must try anyway. If you can keep the thing at bay long enough, I will be able to begin the bombardment of Ilissus.'

*And what about Sergeant Halser?'

Mortmain lowers his head. *I will pray for him too.'

CHAPTER NINE.

Baron Cornelius van Tol stumbles awkwardly to the door of his chamber, clumsy with fear. The dry, ironic tone is entirely absent from his voice as he calls for his guards. *Something is approaching,' he cries as ranks of soldiers, wearing peaked caps and epaulettes, hurry towards him. *The inquisitor has sent some kind of...' His words trail off and he seems unsure how to continue. He shakes his head. *No, not Mortmain, this is something else. Something worse. Man the doors!'