Ventanus splits his Ultramarines into four spearheads, the faster vehicles moving on the flanks while the super-heavies and Dreadnoughts advance up the centre. Ventanus commands this element. Selaton commands the left, Sydance the right. Urath of the 39th will rendezvous with them at the Malonik Transit, and the strike force will swell as more of their scattered brothers bleed in from each of the Lanshear Arterials.

The Burning Cloud, the Titan that killed the traitor engine Mortis Maxor, marches over the buckled superhighway of the Tarxis Traverse, its warhorn echoing mournfully over the ruins. Captain Aethon's warriors are sweeping down from the north, but his force will only join with Ventanus when they meet in the middle of Foedral Fell's ruined fortress.

The last element of the assault force is Eikos Lamiad.

Tetrarch of Ultramar, Primarch's Champion. Eikos of the Arm they call him now; his army is an eclectic muster of forces stitched together from the survivors of the parched deserts and burning muster fields around the Holophusikon. Army, skitarii and Defence Auxilia rally to his banner, together with the great Telemechrus the Sky Warrior, the twice-birthed.

With his arm lost to Word Bearers bolts, Lamiad's warriors have declared themselves his Shield Bearers. Already the survivors of the attack are building a mythology.

Perhaps there is something to Sydance's assertion that they will all have names of legend by the time this war is done. Something to inter in the museum of the future.

Ventanus drags his thoughts from potential futures to the present.

He has brought together a force greater than any assembled since the muster. This is an appropriate response. What little information Tawren was able to collate from the brief link with the Word Bearers cogitators before the betrayal indicates that Foedral Fell is a war-leader of great prowess and charisma.

If he is allowed to effectively rally the Word Bearers, the war for Calth will take decades.

That cannot be allowed to happen.

His fortress stronghold in the foundry districts must be razed to the ground.

The going is slower than Ventanus would like, but his time-table has allowed for this. A number of paths thought clear from orbital pict-capture are proving to be impassable on the ground. The Land Speeders are creating passage with their guns or feeding back updated routes.

In five hours the co-ordinated arms of the Ultramarines assault will be at the outskirts of Foedral Fell's stronghold, within minutes of the fresh telemetry from orbit.

And armed with the most up-to-date information at his disposal, Ventanus will wipe Foedral Fell from the face of Calth.

XVIII.

Hol Beloth follows Maloq Kartho into the ruins of a Lanshear starscraper whose spine has been broken. The towering structure lost its upper three hundred storeys when the portside void array of the Antrodamicus sheared them away with the precision of a thousand-metre blade. The shock of that impact buckled the ventral pier and robbed the building of its structural integrity. The starscraper creaks and groans in the howling winds, and wide cracks have spread from the floor to the metres-thick support columns.

It is only a matter of time until the tower collapses.

Neither this nor their proximity to a known Ultramarines stronghold seems to bother Maloq Kartho, who leads their small warband into the corpse-choked atrium. Concussive force from an engine engagement three kilometres away on the Niansur Lateral blew out the building's heliotropic windows, and the scorched bodies are shrouded in ash-stained glass with brittle reflections.

Eriesh Kigal and his Terminators have said little since they took possession of the weapon from the disintegrating cult-warriors. Zu Gunara is even more uncommunicative, and Hol Beloth is beginning to feel like less of a commander, and more of a passenger.

'Why are we here?' he asks, stopping in the midst of the corpses. A flaking skull, black and pitted, stares up at him, the jaw sagging open with the vibration of his footfall. He crushes it beneath his boot.

'You ask a question that has vexed the greatest minds since man first learned to walk upright,' replies Kartho. He puts a hand out to support himself, as though weary from their trek across the shattered hinterlands of Calth. Their armour is straining to keep the worst of the radiation at bay, and the power capacitors in their backpacks will need to be charged soon.

Yet what they have endured is nowhere near enough to tire the Dark Apostle.

Only now does Hol Beloth realise that Kartho no longer has his Octed staff.

'You know what I mean,' says Hol Beloth. 'Here. This building. Why?'

Kartho cranes his neck upwards, looking through the great void at the building's heart. Hol Beloth follows his gaze. Dust and particles of glass spin in light filtered through the broken windows. They form strange patterns, spirals, loops and hints of suggested forms just out of reach. For the briefest moment, Hol Beloth sees something in the dancing motes, but it slips from perception even as he thinks he sees it.

'We are here to witness something,' says Kartho, as though that explains everything.

'Witness what?' demands Hol Beloth, his hand curling around the leather-wrapped grip of his sword. He no longer cares if the muttering shadows attack him, he simply wants answers.

'A moment in history,' says Kartho, holding up his hand to forestall another angry outburst at his cryptic answer. 'Contrary to what some believe, the universe is not a sterile place. It is a grand melodrama, a tapestry of consequences, both man-made and celestial. Most are minor things, easily missed, but some are of galactic significance, universal even. And these dramas must be witnessed if they are to register in the universal paean to the dark monarchs. A number of such dramas are close, and we are here to bear witness to one.'

'What's going to happen?' asks Hol Beloth.

Kartho sighs and says, 'Climb with me and we will witness it together.'

Hol Beloth looks back up the atrium. Even with its top sliced away, the starscraper still soars to a height of nearly a kilometre and a half.

'I suppose it's too much to hope that the transit lifts still have power?' says Hol Beloth.

Kartho laughs, a mockery of the sound.

'Good drama is earned,' he says, setting off towards a dust and corpse-choked stairwell. 'And, trust me, you won't want to miss this.'

XIX.

Like everything to do with the war on Calth, Foedral Fell's stronghold is a thing of ugliness. Dismantled manufactoria have provided the raw materials for his fortifications: sharp-edged bastions, low-lying artillery deflectors and sunken blockhouses. It is a cancerous blight on the landscape, a fog-wreathed, orange-lit vision of damnation. Tar-black smoke streams up like claw marks on a canvas, and the air stinks of petrochemical fires.

Ventanus remembers a Word Bearer who called himself Morpal Cxir who claimed that Foedral Fell's warhost numbered in the tens of thousands. Those numbers will have been decimated by Tawren's orbital strikes, but by how much is the real question.

'Come on...' he mutters, watching the counter on the main slate diminish.

At last it reaches zero, and heart-stopping seconds pass before the combat logister flickers to life. Real-time data inloads from the geo-sats. Information pours in. Ventanus processes it instantaneously, parsing tactical feeds on avenues of approach, heat signatures, topographical layouts and enemy troop dispersals. He had feared that the Word Bearers might have their own scouts in place and be ready for them, but it now appears that he was wrong to credit the enemy with such foresight.

Readiness icons flash on the logister as the information passes down to his force commanders. They have seen what he has seen, they are hungry for this fight: dogs of war, straining to be let slip. Even Lamiad defers to his command. It is Ventanus's right and honour to give the word.

His theoretical is solid. The practical is in place. They all know it.

'All commands, unleash havoc,' orders Ventanus.

XX.

The plotter table within the Ultimus is not designed to handle military-grade inloads. Its Lexaur-Kale photon arrays were designed to distribute system-wide shipping timetables and manifest lists, not co-ordinate Legion war-planning. Server Tawren has been forced to make numerous alterations to its bio-organic cognitive centres.

Most are sanctioned modifications, but a few are those taught to her by Koriel Zeth during her apprenticeship at the Magma City. Not forbidden, per se, but frowned upon. Hesst would have approved, and the thought of her binary life-partner observing her work makes her smile.

Colonel Hamadri and Captain Ullyet are present, but they are ghosts to her. Unaugmented and without noospheric enablement, little more than blurs in her peripheral vision. All she sees is data. They are speaking softly, but she does not hear them.

Calth's atmospherics are lousy with rad-squalls, but Tawren has learned to compensate for this. She adjusts her filters and the optics of the geo-sats respond to her commands. Static blurs. Holographics waver. Resolution refreshes and she sees what she needs to see.

She reads the energy signatures of buried power sources, thermal blooms from what are most likely barrack structures. Everything the Word Bearers have tried to hide is laid bare before her and she relishes the godlike aspect to her current position.

Everything she is seeing is consistent with the deployment characteristics known of the Word Bearers. Heat patterns are consistent with Legiones Astartes power plants, and this reassures her that nothing significant has changed since the last exload from the geo-sats.

Half a dozen savants and logi are plugged into the table, each assigned to a command element of the assault force. The geo-sats send their findings back to Arcology X in compressed data blurts, which are then passed to the attacking Ultramarines. Each Space Marine commander has his own dedicated battle-savant to break the data inloads into packets of information more easily digested by those without cognitive process augmetics.

The bio-architecture of Space Marine brains is greatly enhanced compared to mortals, but they are not Mechanicum.

'Geo-sats will remain overhead for another fifty-three seconds,' says a savant with dark skin and warm eyes that are still his own. 'Five three seconds.'

His accent is equator-thick, and Tawren likes the flexing epenthesis of his words.

She watches the inloading data spread through the plotting table, the gold icons moving in a carefully orchestrated ballet. Everything moves with precision. Every sweep and thrust made by the warriors of the XIII is perfectly co-ordinated.

It does not feel like watching a battle, it feels like watching a replay of a battle.

Her eyes flick to a noospheric countdown hovering over the rune indicating the force element containing Captain Ventanus.

XXI.

The Shadowsword fills with crackling electrical feedback as its main gun fires. Static charge lifts energised dust fragments from armour plates and makes the hairs on the back of his neck stand to attention. Ventanus could have ridden into battle within a Land Raider, but the awesome destructive potential of the Shadowsword was too great to resist.

On the grainy pict-slate before him, a wall disintegrates as the super-heavy's main gun obliterates it. This is a tank capable of killing battle engines. An ad-hoc fortification has no chance. Bodies tumble from the wreckage, cultist bodies. Those that are still recognisable as human are on fire.

Ventanus cannot hear their screams, but wishes he could.

His capacity to enjoy the suffering of his enemies has become something feral.

Ventanus activates the pressure seals that isolate his forward station from the rest of the super-heavy. He wants to see Foedral Fell's stronghold laid waste with his own eyes.

A green bulb lights up beside him. Pressure seals secure.

He enters his command code onto an oversized keypad. The hatch above unlocks with a snap of vulcanised seals and durasteel locking bars. It slides back and Ventanus pushes himself upright.

Flames surround the tank as it bludgeons its way through the outer reaches of Foedral Fell's defences. Bands of brotherhood warriors in scavenged exo-suits run from the Shadowsword. None of their weapons are capable of denting its thick armour, and they know it.

Banks of heavy bolters mow them down as they flee. Streams of las and solid rounds saw through their disordered ranks. Plumes of hot blood puff from their exploding bodies like geothermal geysers.

Ventanus slews the pintle-mounted combi-bolter around and hauls back on the arming lever. The magazine engages with a satisfying clatter and he mashes the trigger. The recoil of a combi-bolter is ferocious, more suited to the man-capable tanks that are Terminators, but the Shadowsword's assembly and his genhanced strength keep his rounds on target.

Bodies detonate, reduced to meat and gristle.

Here and there a warrior band holds its ground. Ventanus has brief glimpses of iron masks, ragged robes and wholly inadequate rad-shielding. They fire weapons that are sub-Army in quality and effectiveness. He wonders how such rabble ever gained a foothold on Calth. He kills them as soon as he sees them.

There are no Word Bearers amongst the cultists, but everything he saw of the fighting before the retreat below ground displayed total disregard for their mortal allies. The humans are here only to slow the Ultramarines' advance, to soak up their fury. If that is Fell's plan, then he has sorely underestimated the well of fury from which the XIII Legion can draw.

Ventanus savours the sight of hundreds of Ultramarines tanks thundering over the hellish wasteland of Fell's outer fortifications. To either side of him, Land Raiders rear up over hastily-raised berms of scorched earth, slamming back down with thunderous force. The enemy warriors who have held their ground are crushed beneath their tracks or buried in the dust. Squadrons of Predators fire syncopated volleys of heavy las-fire and the fiery contrails of Whirlwind missiles arc overhead in dizzying numbers.

Squadron upon squadron of Land Speeders flit like murderous raptors over the battlefield, strafing exposed enemy formations. Their multi-meltas breach bunkers, and Assault squads drop in their wake to end pockets of resistance with shrieking chain-blades and pistols.

The Burning Cloud strides in from the east, its guns wreathed in smoke and light as it sears the sky with magma blasts. Mushrooming explosions erupt in the centre of the fortifications. Adamantium walls are turned to slag with each impact. Air-bursting rockets flare from the Titan's void shields, and its warhorn sounds like booming laughter.

Ventanus brings a tactical overlay onto his visor. Gold icons close like a fist on Fell's fortification, but these are just the outer layers. Easily overcome. The real defences are a kilometre ahead, towering walls that can withstand a Titan's guns, hellish bastions of dark steel and sunken bunker complexes that even a Shadowsword will struggle to breach.

But he has bigger guns than even a Reaver or a Shadowsword can mount.

Ventanus opens a vox-channel to Arcology X.

'Meer Edv Tawren,' he says. 'Just like before.'

XXII.

Tawren links with the orbital guns and disengages their safety protocols with an outward sweep of both hands, like an actor parting a curtain and taking the stage. It takes a moment for the multiple layers of security put in place since the invasion to disengage, but each platform comes under her command without issue.

Every orbital gun is now slaved to Arcology X.

She has control.

'Brace for full bombardment,' says Tawren.

XXIII.

For a single, beautiful moment, Calth's night ends.

The poisoned air lights up. Daylight returns.

But it is a false dawn, heralding not the promise of fresh beginnings, only endings.

The undersides of clouds heavy with acid rain glow for an instant as high powered lasers burn through them. Meson trails flash-burn the volatile, chemically-rich bands of vapour that have gathered above the strongpoint. The landscape is lit up for hundreds of kilometres as the sky catches fire.

All of this happens in an instant. Fractions of seconds later, searing beams of energy slice down from space like arrow-straight lightning. The beams make no sound in themselves, but the atmosphere ignites with their passage. Each impact is swiftly followed by a hard bang of displaced air.

Ventanus watches it through the filtering insulation of his armour's auto-senses. Aural dampers resist deafening cracks of thunder that would otherwise rupture his eardrums. Visual protection keeps him from being blinded. Ceramite plates protect him from heat that would sear the flesh from his bones.

The exposed cultists have no such protection and their formations are reduced to swirling banks of meat-smoke. Skeletons have the flesh burned from them, blood boils and impregnable walls are left as little more than heaped rubble.

The first wave of overpressure hits and the ground quakes. The Shadowsword rocks back on its suspension as the percussive blast slams into it like an army of Contemptors slamming its hull with graviton hammers. Ventanus leans into the blast wave, riding out the pummelling force. His link with the super-heavy tells him that numerous onboard systems have failed. Feed lines rupture, hydraulics burst and delicate systems overload.

A kilometre from the nearest impact point, and still they are too close.

Laser lances and kinetic rounds all slam down on Foedral Fell's stronghold, blowing out its pathetic blast shielding and rudimentary void fields. There is nothing left of the fortifications. Its soft underbelly has been exposed and Ventanus has the harpoon ready to thrust.

Excited chatter bursts over the vox. A hundred voices all saying the same thing.

'Did you see that?'

'Throne!'

'There can't be anything left alive in there!'

Ventanus knows there will be survivors. The Word Bearers will not be dug out so easily.

He cuts across the vox-network.

'We still have a practical to achieve,' he says. 'Carry out your orders.'