*Like knights from a bygone age of Terra,' said Kane, setting off along the serried ranks of thousands upon thousands of suits of armour contained within the chamber. *A byword for honour, duty and courage.'

*My lord?'

Kane gestured towards the armour with a dramatic sweep of his hand. *This armour is a resource more precious than the wealth of worlds, Lachine. On most days it gives me great satisfaction to know how much the Astartes depend on us. I can normally lose myself in this place.'

He saw Lachine about to speak and said, *Not literally, of course. I look at the sheer volume of armour stored here and, even though none of these suits are occupied by one of the Emperor's finest, I am still awed by the power of the Astartes and take solace that we are protected by such awesome heroes.'

*Conclusion: your words lead me to infer that on this day you do not take the same satisfaction you would normally.'

*Indeed I do not, Lachine. Despite my attempts to immerse myself in the daily tasks of the forge, I find my thoughts returning to the chaos that has engulfed our beloved world over the last few weeks.'

Beginning on the day the freakish and unnatural storms had broken over the faraway peak of Olympus Mons and the devastating machine plague had wreaked havoc across Mars, an epidemic of riots, suicides and murders had swept through Mondus Occulum, claiming thousands of lives and, more importantly, doing untold damage to the production facilities.

Scores of factories and weapon shops had been destroyed, burned to the ground or smashed beyond repair in the whipping, shuddering waves of panic and psychosis that had swept through the habs and factories like contagious lunacy.

The forge marshals had been unable to cope with the paroxysms of violence and, though it pained him to do so, Kane had ordered them to withdraw and allow the rioters to run their course.

*Who would have thought such trouble could have been touched off by a freak weather system over three thousand kilometres away?' he said.

*Studies by Magos Cantore have shown that uncomfortably cold weather can stimulate aggressiveness and a willingness to take risks, while apathy prevails in the heat,' said Lachine. *Additional: temperature has previously been shown to affect mood, which in turn affects behaviour, with higher temperature or barometric pressure related to higher mood, better memory, and broadened cognitive style. Humidity, temperature and hours of exposure to sunshine have the greatest effect on mood, though Cantore believes humidity to be the most significant predictor in regression and canonical correlation a.n.a.lysis. Implications for the climate control of forges and subsequent worker performance are discussed in detail in the study's conclusion. Would you like me to summarise them?'

*In the name of the Omnissiah, please don't,' said Kane, striding onwards into the depths of the armorium. Lachine and his retinue struggled to match his long, purposeful stride.

As the panting Lachine drew alongside him, Kane said, *Certainly, its absurd to believe that a meteorological phenomenon, even one so fierce, could affect the psyches of so many, yet the evidence before us is hard to ignore. However, the damage was not restricted just to the cognitive processes of the forge's population.'

That fact troubled him more than any other.

As the storm raged over Olympus Mons, the vox-lines and data highways of Mars had swarmed with screaming, shrieking packets of corrupted data that sliced into the delicate systems that governed almost every aspect of the workings of Mondus Occulum.

The outlying forge cogitators and logic engines had clogged with corrupt data, howling ghosts of sourceless machine-noise and dangerous code packets of infected algorithms that many of the most advanced aegis protocols were helpless to defeat.

Only Kane's swift action to shut down the I/O highways and the fact that the vast majority of his systems had recently been upgraded to take advantage of Koriel Zeth's revolutionary system of noospheric data transference had spared them the worst of the attack, for an attack it surely had been.

*How much longer do the code-scrubbers need before they will have my system cleaned out?' he asked.

*Current estimates range from six full rotations to thirty.'

*That's a wide range. Can't they narrow their estimation?'

*Apparently the corrupt code is proving to be most resilient to their efforts,' explained Lachine. *Each portion of circuitry that is certified purged soon develops faulty lines of code at a geometric rate once again. They dare not reconnect any system touched by the polluted algorithms for fear of re-infection.'

*Have they identified its point of origin?'

*Not with any certainty, though the infection of systems appears to be spreading outwards from the forge of the Fabricator General, suggesting that it was the first to suffer.'

*Or where it was released,' muttered Kane. Despite repeated attempts to communicate with Kelbor-Hal, every transmission had been rebuffed by squalling code screams like barking dogs or was simply ignored.

*Query: you believe this sc.r.a.pcode to have been released into the Martian systems on purpose?' Even the normally logical and literal Lachine could not keep an emotional response from his voice at the notion that the sc.r.a.pcode had been unleashed deliberately.

Kane cursed himself for his verbal slip and shrugged.

*It's a possibility,' he admitted, keeping his tone light. He didn't particularly want to voice his suspicions to Lachine. His apprenta was loyal, but he was naive, and Kane knew that information could be thieved by any number of means from supposedly secure sources.

No, the less Lachine knew of Kane's suspicions the better.

According to the code-scrubbers, the sc.r.a.pcode had attempted to shut down the vox network and defence protocols that protected his forge and then release the tension in the Tsiolkovsky towers' guy wires. Kane had shut off the links between Mondus Occulum and the rest of Mars in an instant, leaving them floundering in the dark, but safe from further attack.

Even communications off-world had become next to impossible thanks to a sourceless backwash of psychic interference. Kane had only been able to maintain contact between the forge of Ipluvien Maximal and the Magma City of Adept Zeth thanks to the noosphere.

The news coming from both was neither rea.s.suring nor particularly illuminating.

Both adepts had suffered similar outbreaks of inexplicable violence and madness among their populace, though only Maximal had experienced serious machine failures, losing three of his prized reactors to critical ma.s.s overloads. Zeth had spoken of a failed experiment that had seen virtually all of her psykers dead, no doubt related to the psychic interference surrounding Mars.

As if things weren't bad enough, Maximal went on to tell of fragmentary communications he had inloaded from the expedition fleets that spoke of an equally terrible catastrophe in the Istvaan system.

Details were sketchy and Maximal had not wanted to speculate without firmer information, but it appeared that a dreadful incident had occurred around the third planet, which was now said to be a blasted, ashen wasteland.

Kane knew of only one weapon that could reduce a planet to such a wretched, h.e.l.lish state in so short a time.

Had the Warmaster unleashed the Life Eater or was this the desperate last act of a defeated foe? Maximal's sources had no answer to that, but claimed that the Astartes had taken fearful casualties.

Whether they had suffered as a result of enemy action or a terrible accident of friendly fire was unclear, but for Astartes to suffer any loss on such a scale was almost impossible to imagine.

Of all of them, Maximal's vox-systems had suffered least in the deluge of unclean code, and he was even now attempting to restore communications with agencies beyond the surface of Mars for further information.

Via secure noospheric links, all three adepts expressed their certainty that the infection of the Martian systems bore all the hallmarks of a pre-emptive strike, but without more solid data, there was nothing they could do but strengthen their defences in case of further a.s.sault.

Kane had heard the fear in Maximal's ridiculously rarefied voice and despised him for it. Maximal was not an easy adept to like and Kane considered him to be little more than an archivist rather than an innovator. Koriel Zeth, on the other hand, had spoken boldly of resisting any follow-up attacks and of how she had despatched envoys to allied warrior orders of t.i.tans and Knights to secure their a.s.sistance.

With Mars under attack from an unknown foe, it was time to gather one's friends close.

Kane respected Zeth, for she reminded him of a younger version of himself, an adept unafraid to push the boundaries of the known. To Kane, Zeth represented all that was good about the Mechanic.u.m, an adept who possessed a proper reverence for the past and what earlier pioneers had developed that meshed with an unashamed hunger to build upon that knowledge to reach still greater heights.

An ancient alchemist and scientist of Terra had once said that he had seen further by standing on the shoulders of giants. That perfectly applied to Adept Zeth, and Kane knew that if anyone was going to advance the cause of science and reason in the Imperium it was her.

Emboldened by that thought, Kane watched as huge, tracked haulers lifted sealed containers of Astartes weapons and armour for transport to the orbital elevators of Uranius Patera.

*Come, Lachine,' he said. *Even during a crisis, the work of Mondus Occulum must continue.'

GREY DUST, LIKE ashen bone, billowed around the legs of the two Knights as they loped along the edges of the Aganippe Fossae, the long trench that carved into the plains west of the towering form of Arsia Mons.

Leopold Cronus led the way in Pax Mortis, with Raf Maven following behind in the newly repaired Equitos Bellum. Cronus set a brisk striding pace, and Maven had to work hard to keep up with him, for Equitos Bellum was skittish, its controls tight, and the Manifold willfully resisted him at every turn.

It knows the thing that hurt it is still out there, thought Maven, angling his course to follow Cronus and the deep canyon. Dust clouds obscured the view from his c.o.c.kpit, but there was little to see in this region and he was piloting via the Manifold anyway. The toxic deserts of the pallidus stretched out to the west and south, and the northern sub-hives between here and Ipluvien Maximal's forge were little more than black smudges of hanging smoke and fear to the north.

The Knights followed the course of the chasm towards the Median Bridge, a section of collapsed rock where they could cross before turning eastwards towards their chapter house within the Arsia Chasmata.

*How's it doing?' asked Cronus over the vox-link.

*It's hard work,' admitted Maven. *It keeps pulling at the controls, but there's no sense to it. Each time I compensate, it returns on the opposite side a moment later.'

*It will take time to readjust,' said Cronus. *The entire link a.s.sembly had to be rebuilt.'

*I know, but it feels stronger than that.'

*Stronger how? What do you mean?'

*Like it's trying to guide me,' said Maven, at a loss how else to explain it. *Guide you? To where?'

*I don't know, but it's like... like something's pulling at me too.'

Maven heard Cronus sigh over the vox and wished he had something more solid to offer his friend by way of an explanation. All he had was a gut feeling and the firmly-held conviction that his mount knew better than he what needed to be done.

Their deployment had begun three days ago, when they left the chapter house in a fanfare of cheers, squires' trumpets, blaring warhorns and waving cobalt banners. Equitos Bellum marched out, and the brothers of the Knights of Taranis had come to watch it walk once more. For a mount to have returned from the verge of destruction was no small matter and the occasion had to be marked.

Like most of the warrior orders of Tharsis, the Knights of Taranis had been on high alert since the chaos that had engulfed Mars began. Thanks to the noospheric links installed by Adept Zeth, the halls of Taranis had not suffered as horrifically as many others had, though the enginseers had been forced to order an emergency shutdown of the chapter house's main reactor after a fragment of sc.r.a.pcode attempted to disengage its coolant protocols.

That speedy response had saved the Order of Taranis from a nuclear holocaust, but until the code-scrubbers could purge the corrupted systems, those Knight machines without full power cells would not be able to recharge.

Nor had that been the worst of the damage. Much to Lord Verticorda's anguish, the data looms of the order's librarium had been corrupted beyond repair, taking with them a roll of honour and battle stretching back a thousand years and more.

At the request of Adept Zeth, Lords Caturix and Verticorda had ordered the Knights of Taranis to ride from their chapter house in defence of Mars and the Magma City. Rumour had it that Zeth had also despatched emissaries to Lord Cavalerio of Tempestus to pet.i.tion their engines to walk, but no one knew what answer she had received.

With several machines powerless to ride until the reactor was repaired, the Knights of Taranis were forced to operate in teams of two instead of three to cover the scale of their deployment. Old Stator had marched out alongside Brother Gentran, a rider newly-elevated from the Errantry, and Maven had been surprised to find that he missed the flinty presence of his preceptor.

Maven and Cronus had ridden east, following a patrol circuit that carried them clockwise around the rumpled skirts of the ancient volcano, before turning to follow the line of the Oti Fossae southwards. As night fell on the second day of their ride, they turned west towards the Magma City to refuel and recharge before continuing on their patrol circuit.

The forge of Koriel Zeth never failed to amaze Maven, glowing like an ember in the distance while the skies above seethed with orange light as though the clouds themselves were afire. Riding closer, lava-filled aqueducts had shone like threads of gold as they carried molten rock from the top of Aetna's Dam, the monolithic structure that formed the entirety of the volcano's southern flank, to the magma lagoon surrounding the city.

Towering walls of ceramite and adamantium ringed the enormous city, and the light of the planet's lifeblood dispelled the darkness as the Knights marched along the mighty, statue-lined Typhon Causeway towards the Vulkan Gate.

Silver and black spires jutted over the walls like metallic teeth, and only after convoluted binaric interrogation by the gate's defences had they been allowed inside. They had stayed within the circuit of the walls just long enough for their mounts' power cells to be brought back to maximum charge before riding out.

The two Knights had continued on their patrol circuit of the enormous volcano, skirting the Magma City's port facilities where millions of tonnes of war materiel was ferried into the hungry bellies of ma.s.s-conveyers hanging low in the crowded skies. No sooner had they left the smoking grandeur of Zeth's city than Maven had felt Equitos Bellum pulling at him, an insistent urge that nagged at his hindbrain and sent painful skewers of pain into his mind whenever he resisted.

With their course soon to carry them eastwards towards home, the pull was getting stronger, and Maven gripped the controls tighter as he felt a building ache behind his eyes. He felt every one of his hard-plugs scratching with irritation, as though Equitos Bellum was trying to dislodge him like a wild colt.

*What's the matter with you?' he hissed.

As if in answer, a ghostly flare on the auspex spiked to the south, and Maven flinched as a surge of recognition pulsed in his mind. The image vanished almost as soon as it appeared and he wasn't even sure he'd seen it, but for the briefest instant it had looked like a dreadfully familiar spider-like pattern of electromagnetic energy.

Maven drew his mount to a halt, feeling the pain behind his eyes ease as he did so. The tall machine's hydraulics hissed as it sank down onto its haunches.

*Cronus, wait!' he called, rotating the Knight's upper body with a deft movement of the controls. There was nothing to see here, just bone white ash and dust whipped in from the southern pallidus. He heard the relaxing groan of metal as Equitos Bellum settled, feeling the tension in its limbs and the restless hunger for vengeance burning in its core.

*What is it?' replied Cronus, and Maven read the telltales of his brother's machine a.s.suming a war posture through the Manifold. *What do you see?'

*I don't know,' admitted Maven. *I don't think there's actually anything out there, but Equitos Bellum's got the scent of something.'

*Did you get an auspex return?'

*Sort of, maybe... I don't know,' said Maven. *It was like a ghost image or something. It was just like the energy signature I saw right before the attack on Maximal's reactor.'

Pax Mortis rode alongside him, and Maven could see Leopold Cronus through the armagla.s.s canopy. His brother looked unconvinced, but not yet ready to write off Maven's a and Equitos Bellum's a instincts for danger.

*Send it over,' ordered Cronus. *The auspex log for the last few minutes.'

Maven nodded, exloading the data from his auspex panel to Cronus' machine in a brief data squirt. As he waited for Cronus to review the data, he cast his gaze out into the depths of the pallidus.

The ashen deserts were desolate and uninhabitable, a landscape of tortured grandeur rendered barren and toxic by rapacious over-mining and unthinking plundering of the resources buried beneath the Martian soil. Pollutants blown in from the equatorial refinery belt carpeted the barren, scarred rock, making it a treacherous landscape of sand-covered creva.s.ses and sinkholes.

Nothing lived in the pallidus, yet Maven found himself unaccountably drawn to grip the controls of his mount and ride south into the wasteland. His power cells were fully charged and he had more than enough reserves of nutrients and water to last him for weeks if need be.

His hands twitched at the controls and he felt the heart of his mount respond to his desire. It goaded him with warlike whispers and an insistent pressure at the back of his mind. His lip curled into a snarl as he thought of hunting the monstrous, dead thing that had almost killed him.

It was out there, and Equitos Bellum knew it. He could feel the certainty of that fact in every molecule of his being. The ghost image had been a reminder of his duty to his mount.

*There's nothing here,' said Cronus, breaking into his thoughts. *Auspex track is clean.'

*I know,' said Maven, with calm, cold certainty. *There's nothing nearby.'

*Then why have we stopped?'

*Because Equitos Bellum is telling me where I need to go-'

*Go?' asked Cronus. *What are you talking about? The only place we need to go is across the Median Bridge and back to the chapter house.'

*No,' insisted Maven. *It's out there. The thing that tried to kill us. It's in the south, I know it.'

*How can you know it?' demanded Cronus. *There's nothing on the auspex. You said so yourself.'

*I know that, Leo, but I saw what I saw. Equitos Bellum can feel it and I trust its instincts.'

*And what? You're going to go after it on your own?'

*If I have to,' said Maven.

*Don't be foolish,' warned Cronus. *Caturix will have your spurs if you do this.'

*He can have them,' said Maven, powering up and raising the Knight to its full height once more. *I need to do this. Equitos Bellum needs this if it's ever going to be whole again.'

*You're willing to risk your spurs by going off-mission on what, a hunch?'

*It's more than that, Leo,' said Maven. *I know it's out there and I'm going after it whether you like it or not.'

Once again, Maven heard Cronus sigh, and though he hated to abandon his friend he knew he had no choice. Equitos Bellum would give him no peace until they had been avenged.

*Very well,' said Cronus. *Where is it? Give me a heading.'