He turns to the Relictor crouched next to him in the ditch. Brother Borellus has his bolter balanced on the scorched earth and his shoulder is jerking back as he fires round after round down the road, picking off the advancing traitors with medical precision. For a second, Comus cannot recall exactly how they got there.

*Where are the others?' he groans, wiping the blood from his eyes.

Brother Borellus holds fire for a second but does not turn around. *Brothers Sabine and Thaler are just behind you, further down the ditch. Stra.s.ser, Vortimer and Brunman are holed up in the barn, although they've taken some heavy hits. Volter is on the far side of the road.' A note of pride enters his voice. *His lascannon is giving them pause for thought.' He fires off another few rounds, muttering happily to himself as more of the traitors spin back into the clouds. *And Sergeant Halser has entered the city, with Inquisitor Mortmain's servant, but...' He looks down at the Librarian briefly, his voice hesitant. *...you know that.'

Comus nods, relieved that Borellus's words make sense. He cannot help but notice, though, that his battle-brother's Low Gothic seems unusually crude and clumsy. He realises, to his horror, that he is comparing it unfavourably to the alien language that has embedded itself in his thoughts. Anger knots his stomach. Why should they have to endure this? Why should they have to prove themselves after so many long centuries of service and so many sacrifices in the Emperor's name? He shakes his head and looks back along the ditch. As Borellus stated, there are another two Relictors crouched behind him firing steadily into the oncoming ranks. Above them, further down the road, rise the walls of Madrepore and its shimmering, hexagonal tower. Prove them wrong, Sergeant Halser, he thinks, grasping one of the religious texts chained to his power armour. Show them what we are worth.

CHAPTER SEVENTEEN.

As Inquisitor Mortmain marches through the Domitus, he draws the billhook from his belt. The black metal blinks red under the flashing lights as he strides through the corridors, swinging it back and forth, testing the weight of the blade in his hand. Crude script runs down its centre: words too vile for even an inquisitor to study. As he reaches a shattered door he pauses, listening to what he hopes is the sound of vast, thermonuclear weapons powering up. But the ship is shaking so violently he cannot be sure if he is hearing the result of his orders or the sound of the approaching daemon.

*Cerbalus,' he breathes, wondering if he has the strength to face the coming encounter. He is an old man, and all the faith in the galaxy cannot match the fury of youth. The officers on the bridge have their orders and they will work fast, but he will still need to buy them time. The inquisitor casts his mind back through the decades to the day he bound Cerbalus to his will. On the scorched earth of Azoras he and his brothers faced the monster down, armed with powerful, ancient wards and a bitter chorus of litanies. But the cabal that saved Azoras is no more. Inquisitors Medeon, Orium and Shaaraim are long dead. This time he must face the beast alone. Even his old friend Sergeant Halser will soon be gone: torn apart by a firestorm of Mortmain's own creation.

Mortmain looks down at the capital I emblazoned across his breastplate. Youth is gone. Friendship is gone. Faith will have to suffice. He kicks the broken door, scattering the blackened metal across the heaving corridor and strides into the next chamber. He enters a pillar-lined cloister, so wide and tall it seems as though he has stepped out into a stormy, summer's evening. The air is cloying, thick and sulphurous. Ancient, beautiful mosaics are tumbling from the walls, exploding across the flagstones like brittle, enamelled rain.

At the far end of the central colonnade there is a shape. It is no more than a shadow amongst shadows, but Mortmain knows his prey. Evil seeps from it like smoke. The inquisitor peers through the darkness, straining to make out details, but the shadow shifts and ripples across the floor, liquid and supple.

There is still hope, thinks Mortmain. The idea surprises him, but once loosed from his subconscious it grows in certainty. *There is hope,' he breathes, realising that the daemon is bodiless; it has no host. Its vile presence has been set loose by Justicar Lyctus and his Grey Knights, and without a physical home it will soon be dragged into the immaterium, folded back into the shifting h.e.l.l that sp.a.w.ned it.

The shadow elongates and drifts down the colonnade, a.s.suming a fixed shape only when it is a few metres away. It adopts the form of a man; or, at least, something resembling a man. It towers over Mortmain, three metres tall and topped by the head of a diseased, slick-feathered carrion crow. As the daemon steps closer, it spreads a pair of ink-black wings and two scrawny arms, delighting in the destruction it has wrought. *Do you think, master,' it asks in an amiable tone, *that, after all these years of service, I might request something in return?'

Mortmain gives no reply, stepping sideways between the columns, pa.s.sing the billhook from hand to hand. He knows his pistol would only feed the thing's strength, but the blade has secrets even Cerbalus does not share.

*Come now,' laughs the daemon. *Is it so much to ask?' Its form breaks apart and rea.s.sembles itself behind Mortmain, causing him to whirl around and adopt a fighting stance. *Think of the squalid deeds I have performed at your request. Think of the blood on my hands that should have been on yours. Surely I deserve a little thanks? A little recompense?'

Mortmain backs carefully away. There is hope, he thinks again as he notices an edge to the daemon's voice. Despite its attempt to sound calm, he senses an undercurrent of emotion. Decades of interrogation have honed his senses until he can discern even the subtlest hints of fear, or anger. As he circles the daemon, Mortmain realises that he has one final weapon: the daemon hates him, hates him with a pa.s.sion that could even blind it to anything else.

*You think I would let your vile presence pollute the body of an Imperial inquisitor?' Mortmain's voice is as calm and even as the daemon's. Suddenly he feels as though his entire life has been building to this moment, this single test of his will. Can he keep the daemon distracted long enough for the crew to launch the attack on Ilissus? Can he play one final trick on a servant of the greatest trickster of them all? *Try me, Cerbalus!' he roars, relishing the look of shock in the daemon's avian eyes. *I will take you down, daemon! Send you back to the pit you crawled out of!'

Cerbalus's huge, ragged wings droop and it tilts its head to one side, surprised to find the old man in such a defiant mood.

Before the daemon has chance to reply, Mortmain snaps a syllable so coa.r.s.e and guttural he has to spit it out with a grimace. As he speaks, the first of the glyphs carved into his billhook blazes with light and he attacks with surprising speed, slashing the blade through the daemon's leg before it has chance to recoil.

Cerbalus screeches. The sound slices through the cacophony, shrill and hideous as it echoes around the towering columns. *How?' it whines, scrabbling back into the darkness, tearing up flagstones with its clawed feet.

*How?' cries Mortmain. *How can I hurt you like that?' He swings the billhook from side to side, flinging inky blood into the shadows as he advances on the huge, cowering shape. The first character on the blade is still aflame with the force of his oath, and as he advances he spits out another contorted syllable. As the sound leaves his lips, a second glyph pulses into life and Mortmain leaps forwards, hacking another chunk out of the daemon's leg.

Cerbalus wails in pain and shock and, with a beat of its enormous wings, hurls itself up towards the distant, ribbed vaults of the ceiling.

*Your name, daemon!' Mortmain's voice is a deep, victorious howl. *I did not share everything with you! Do you think I have been idle all these long decades? Do you think I never foresaw this moment?' The inquisitor climbs on the shattered stump of a marble column and levels the billhook at the shape hovering overhead. *Face me, abomination! Or are you afraid?'

Cerbalus swoops across the chamber and wraps its shifting form around one of the pillars, several metres above Mortmain. At the word *afraid' its bird-like head snaps around and glares at the inquisitor. *Afraid?' it screeches. Its rage is so great that its form shifts through dozens of shapes, trembling and flickering in and out of view. *You are nothing! You are the lapdog of a puppet corpse. How can you even look at me? You are an insect!'

The lights in the chamber dim as a grinding, deafening hum rumbles through the walls.

The daemon snaps its head in the other direction, peering at the broken door. *You have already begun,' it whispers. *Exterminatus.'

The chamber lurches to one side and Mortmain is forced to grab a pillar to steady himself. *Go, then, daemon,' he cries. *You will find nothing but pain here.'

Cerbalus looks back at the inquisitor, its eyes full of dark fire. *What would you know of pain?' The daemon launches itself from the pillar, ripples through the darkness and materialises next to Mortmain.

Before the inquisitor can raise his billhook, a ragged, filthy claw slices through his leather cloak and sends him flying across the room in a spray of blood. He slams into a pillar with a howl of pain and scrambles away into the darkness, cursing under his breath.

Cerbalus spins on the spot, spreading its wings and arching its long neck as it laughs with pleasure, forgetting everything but the ecstasy of revenge.

Mortmain staggers from pillar to pillar, his head spinning. Once he reaches the far side of the chamber he pulls back the shreds of his cloak to reveal an arm that is equally torn. His left bicep is completely ruined, hanging from his tattered flesh like raw steak. As the daemon continues spinning through the shadows, laughing to itself, Mortmain tears a strip of leather from his cloak and ties a quick tourniquet. He still has the glowing billhook in his right hand, and as he taps it against his breastplate he is relieved to feel that it is still intact. Without the prayers and sigils worked into its ornate metal, the mere presence of the daemon would split his mind as thoroughly as his ruined arm.

Suddenly the laughter is right next to him, but this time Mortmain is ready. He rolls clear of the daemon's claws and chants a third, potent syllable, lighting up another character on his weapon.

Cerbalus cringes at the sound, but before it can withdraw its claw, Mortmain chops down with the billhook, slicing another piece of the daemon and causing it to screech in pain and frustration.

This time it does not flee, though. Before Mortmain can draw breath for another letter, the daemon stoops low over him and a talon rips open his thigh, sending him toppling to the ground. The pain is like nothing he has ever experienced but, as he slams onto the floor, he manages to gasp another syllable and lash out with the billhook.

Cerbalus croaks and gurgles as the blade rips open its throat.

By now the inquisitor's black weapon is alive with flaming characters. *I have your name!' howls Mortmain, attempting to disguise the lie by screaming it with all the force he can muster. *I will banish you, Cerbalus! You have no place here!'

The daemon's twisted, stooping form backs away from him, clutching at the wound in its throat, unable to comprehend how the inquisitor's weapon could sever flesh that does not even exist. *My name? How could you?'

The lights dip again as another deafening rumble fills the chamber.

Almost there, thinks Mortmain. Just a few more minutes.

The daemon looks at the doorway, its head twitching with indecision. It looks in the direction of the Domitus's bridge, then back at the gore-splattered man writhing at its feet. It peers suspiciously at the short, curved blade pulsing in Mortmain's grip, trying to make out the characters that have yet to ignite. *You do not have the power to wield such a thing. If my name were really held in that piece of metal it would tear your mind open.'

Knowing that he only has to maintain the lie for a few more minutes, Mortmain screams another syllable and attempts to stab Cerbalus again.

The daemon beats its wings and disappears.

Mortmain's broken body floods with adrenaline at the thought that the daemon has given up on him and made for the bridge. Then he sees it reappear, crouched like a gargoyle on the broken pillar where he was standing a few minutes earlier.

*My flesh is not for one such as you!' he cries, spraying blood across his breasplate. He tries to stand, but his leg collapses beneath him and he sprawls across the flagstones like a drunk. *Try me, Cerbalus. Just a few more characters and you will be in my power once more.'

Cerbalus lets out a scream that even drowns out the klaxons. It launches itself from the pillar, smashing headlong into the inquisitor and sending them both tumbling across the b.l.o.o.d.y flagstones.

As they roll, Mortmain continues crying out the foul syllables and hacking into the daemon's shifting flesh, even as Cerbalus's frenzied claws tear his body apart.

Finally, they come to a halt against the feet of a statue and Mortmain begins to laugh.

*You are mine!' screams the daemon, lifting the inquisitor up into the air by the throat and shaking him like a broken toy.

Mortmain continues to laugh even as his innards spill to the floor. The chamber is shaking more violently than ever as the Domitus's weapons silos finally launch their missiles at Ilissus.

*Perhaps you will have me after all, Cerbalus,' he laughs, vaguely aware that silver-clad figures are emerging from the shadows, their weapons trained on the daemon. *But you will never have Ilissus.'

Far below, the planet's surface flashes red, then purple, then a beautiful opalescent white as it begins to die.

CHAPTER EIGHTEEN.

The temple of Astraeus is the grandest of follies. As Halser races through the great hall its walls swoop and bulge around him like the sails of a ship. Every inch of the place a floor, ceiling and walls a is studded with thousands of eyes, all of which follow the sergeant as he pounds towards the archway at the far end. The windows have been constructed in such a way that stars appear to hang in the air, and the dervish-like eddies of dust and cloud are even more fierce inside the building: waltzing and swaying like dancers across the floor, merging seamlessly with the undulating walls. It seems to Halser that he has been cut adrift in the heavens, and as he runs he weaves drunkenly from side to side, disorientated by the extraordinary display.

*Heresy!' whines Pylcrafte, stumbling after him and firing shots at the walls with his laspistol, shattering as many of the blinking eyes as he can. *Heresy, heresy, heresy, heresy, heresy!' He has his cane in his other hand and he tries to stab the rolling clouds, hacking and lunging like a deranged swordsman.

Halser ignores him and keeps running towards the archway.

*He's going to unfetter us.' Comus's pain is clear to Halser, even over the vox. *Whatever he's doing, it's going to unhinge time.'

*I don't understand!' cries Halser, reaching the archway and leaning against the stone to catch his breath.

*Ilissus is heading towards some kind of time loop. Maybe even the whole sector. Whoever this prophet is, you need to stop him.' There is an uncharacteristic note of fear in the Librarian's voice. *You have to kill him, sergeant. The Black Legion want him to succeed. They have only attacked now to stop us hindering him. They could have struck at any time. He is dangerous, Halser. More than I guessed. Maybe he doesn't even realise it himself.'

Halser shakes his head and stumbles into the next chamber. *A time loop? I don't understand.' The room he has entered is a vast, gla.s.s-roofed atrium, surrounding the hexagonal tower at the heart of the temple. Most of the pilgrims have fled to the walls to launch whatever strange defence they can manage, but a few are leaving the tower as Halser approaches. They drop to their knees and start screaming, horrified by his presence in their inner sanctum. The sergeant gasps and reels backwards. Their screamed prayers fill his head like a sickness. The pain s.n.a.t.c.hes his breath and he stumbles, gasping inside his helmet, unable to breathe. He drops to his knees, feeling unconsciousness looming. Before he blacks out, he fires his bolt pistol. The shots are wild and frenzied, but one of the pilgrims crumples to the floor and the pain lessens. Feeling stronger, Halser manages to stand and fire off a few more shots. The pilgrims make no attempt to flee and it takes seconds to kill them. Then he staggers on, feeling his mouth filling with blood.

Pylcrafte staggers after him, waving his cane at nothing as he goes, trying to strike the prayers that fill the air.

Halser does not pause as he pa.s.ses the pilgrims' corpses and enters the tower. He sees a wide, serpentine, spiral staircase and begins to climb. His mind is numb with pain. He can barely remember his purpose, beyond a fierce drive to reach the architect who summoned this nightmarish temple into being. As he climbs the stairs more of the pilgrims launch attacks on his mind, but he guns them down without even pausing, haunted by Comus's ominous term: *time loop'.

*Pull back to the city!' cries Comus, staggering through the shrapnel and smoke, and pointing his force sword at the walls of Madrepore. *We have to buy Halser some time. We can hold them at the gates!'

The barn has become a smouldering crater. Brothers Stra.s.ser, Vortimer and Brunman are dead. The remnants of their power armour is scattered throughout the rubble, torn open by the enemy's heavy artillery. There are five Relictors left to make the run. Brothers Sabine and Thaler help Comus while Borellus and Volter give them covering fire.

After a few minutes, Volter lowers his lascannon and races down the road after them, but Borellus remains crouched in a ditch, firing blast after blast with his bolter.

*Borellus!' snaps Comus as he reaches the relative safety of the city. *Move!'

Brother Borellus shakes his head and continues firing.

Volter reaches the gates and rolls clear as a storm of bolter fire follows him into the city.

Comus jerks to one side as a hole explodes in the wall next to him. Then he peers briefly through it and sees that Borellus is still in the ditch, firing as calmly as ever, despite the fact that the enemy ranks are almost on him.

*Borellus,' he repeats, but there is no command in his voice now, only respect.

Borellus nods calmly in reply, then vanishes from view as the black-clad figures swarm over the ditch.

Comus hears a brief cough of pain over the vox as the Traitor Marines tear Borellus apart, and he lowers his head in prayer. Then he looks around the city. Hundreds, if not thousands of pilgrims are gathered on the city walls. He can feel the weight of their prayers as they try to repel the attacking army. And he can also feel their panic as they realise their words are having no effect.

*They could have killed you at any time,' he mutters, his voice full of disgust. *But they wanted your prophet to complete his work as much as you did.' Then he notices a low, flat-roofed building to the left of the gates, with thick walls and small windows. He waves his force sword at the building and staggers towards it, ignoring the sound of enemy fire pulverising the city walls.

The other three Relictors sprint after him.

By the time Halser reaches the top of the stairs his mind is like that of an animal closing in on its prey, blind to everything but the chase. The City of Stars is collapsing but all he can think of is the prophet. He can barely remember why, but he knows he must stop Astraeus, even if it means his life.

Ahead of him is a tall, white door, studded with the same rolling eyes that line the walls. He pauses for a second and looks at them; blue, grey and brown irises look back, filled with terror and hate. Hate. Suddenly Halser remembers something other than the prophet of Ilissus. He remembers every doubt, rumour and lie that has been levelled at his beloved Chapter. An involuntary growl rolls deep in his chest and he shoves the door open, entering the central chamber.

The scene that greets him is strange enough to halt him in his steps. Pilgrims line the walls, kneeling in the five corners of a room built in the shape of a star, and the object of their genuflection is even more peculiar than they are. The man that Halser a.s.sumes is the prophet is as tall as a s.p.a.ce Marine, but where Halser is an armour-clad hulk of muscle, the prophet is a grey, emaciated wraith of a man, draped in voluminous black robes that hide most of his skeletal frame. His flesh is the colour of rain clouds and his limbs and hands are oddly elongated. The fingers clutching the arms of his ornate throne resemble pale spider's legs; they are also webbed, like those of a lizard and end in long, crimson talons. Strangest of all is his head. It is swollen to three times the size of a normal skull and it is contained within a spherical, liquid-filled bowl. His eyes are barely visible behind thick, tinted goggles that also cover most of his forehead, and his pallid skull is pierced by a forest of thick wires that emerge from the gla.s.s helmet and connect to a bewildering collection of measuring devices: bra.s.s s.e.xtants, compa.s.ses and spinning, ticking depth gauges are all piled on the gla.s.s bowl like a rusty crown.

Despite everything he has seen on Ilissus, the sight of the prophet leaves Halser speechless. Everything strange about the planet clearly emanates from this one, bizarre figure. The coils of cloud that spread from the temple to the heavens are all trailing from his swollen, smiling face.

It takes Pylcrafte, stumbling into the room a few moments later, to state the undeniable truth. *Youayou're a Navigator,' he stammers, as his nest of cables snake from his hood to focus on the prophet.

Astraeus smiles, eliciting a chorus of sighs from his subjects. *I used to be.' His voice sounds odd and distant, m.u.f.fled by the liquid in his helmet, and as he speaks the air in the chamber ripples like heat haze. *I was once Iarbonel van Tol, the first son of Baron Cornelius van Tol. But that was a long time ago, and I have a suspicion I might have been disinherited. The Emperor has a better name for me now, though, and a far greater purpose.' He fixes his gaze on Halser. As the light in the chamber swells, his eyes become visible behind the lenses of his goggles.

Halser forgets his purpose for a moment, hypnotised by the prophet's stare, then he shakes his head and recalls the words of Comus. *What are you doing here?' he snaps, waving his gun at the rolling clouds and the banks of eyes. *What sorcery is this?'

The prophet's smile falters. He frowns, clearly surprised by the accusation of sorcery. *I have watched you from afar, s.p.a.ce Marine,' he says. *I thought you at least would understand.'

Halser continues shaking his head, too confused to answer.

*When the Emperor cast me down onto Ilissus I thought He had abandoned me.' The prophet waves at the ceiling. *My beloved ship was utterly destroyed.'

Halser looks up and notices Imperial designs, warped into the strange architecture, as though the whole place has been grown from the carca.s.s of a battleship.

*My injuries were horrendous,' he turns his head slightly revealing the signs of crude, brutal surgery on the back of his skull, *but my children kept me safe.' He smiles at the adoring pilgrims. *Over time, I realised the damage to my brain had untapped my true potential. That is all you are seeing here, sergeant: the true potential of a loyal subject.' He flexes his fingers and the air ripples visibly, like water. *Soon I will have the power to crush those who would oppose us.' His voice grows higher in pitch. *I will be invincible.'

Halser grips his bolt pistol tighter as he remembers his goal. He must stop this deluded monster before he tears the whole galaxy apart with his witchcraft. He raises his gun and mutters a prayer, but before he can fire, the temple lurches to one side.

The pilgrims' prayers become a scream of terror as the walls start to bulge and sag.

*It is beginning,' smiles the prophet, leaning his head forwards so that the gla.s.s bowl touches Halser's gun with a clink. *Your friends have sent you to your death. They want us to die together.'

Halser gasps. *You're a liar!' he cries, but as he speaks he recognises the scale of the explosions. He s.n.a.t.c.hes the chronograph at his belt. *I still have time!' He looks at the crumbling walls in disbelief. *Mortmain would not do this to me!'

The prophet nods. *They fear courage more than anything. My own father has sent them to kill me. And you...' He pauses. *They sent you here to die, my friend. Your death, by my side, will be their final proof. Now they will speak openly the word they have long whispered against you: heretic.'

I am betrayed, thinks Sergeant Halser. Betrayed.

*Comus is down!' howls Brother Volter over the vox. *Dead, maybe... IaI can't be sure. They've taken the infirmary. I'm pulling back. What are your orders? Sergeant?' His voice is broken, his words half-buried beneath the sound of artillery. *Are you there? Sergeant Halser?'

Halser keeps his gun pressed to the prophet's head and gives no reply. The pilgrims scream at him from the shadows, but he keeps his gaze fixed on a pair of grotesque, fathomless eyes.

The prophet stares back.