The Iron Warrior and his servitors pursued, occasionally raking the Scions with quick bursts of fire to keep them invested. Employed as a prod, the judicious use of a Reaper chaincannon was a powerful motivator. He activated his auto-senses’ preysight as he followed them into the lower fortress, banishing the darkness beneath a riot of heat signatures and motion sensitivity.

  ‘Numus, the signal dome has collapsed. What is happening?’

  Blodt sighed. Zelazko’s timing was terrible, as usual.

  ‘Merely a test, brother. Don’t trouble yourself.’

  ‘You still have not transmitted the plans.’

  ‘I am in the process of compiling new and comprehensive data,’ Blodt said. ‘I will forward it shortly.’

  ‘Shall I send Matebos?’

  Blodt ground his teeth. That hurt.

  His irritation got the better of him as he raked fire across the loyalists with unintentional accuracy. The one who had shot him at Kiemchek collapsed beneath his fusillade, forcing him to intentionally pull the rest of his shots so that her fellows could drag her clear – he had something special in mind for her, and he would be remiss if he allowed a moment’s choler to spoil it.

  ‘Have I ever failed you, Shomael?’ Blodt asked indignantly.

  ‘Numus…’

  ‘If submitting the Warsmith an incomplete assessment is sufficient for you, brother, then I will do so immediately – with an addendum that I was provided with inadequate time to sufficiently test my design and my requests for deferral went unmarked. I am certain he will understand.’

  That shut him up.

  ‘Just finish what you’re doing and get me that data,’ Zelazko said sourly. ‘We are rapidly falling behind schedule.’

  The link fell silent.

  Blodt grinned. It was so easy to vex his younger brother when he was yoked to a schedule. For years, Blodt had been saying that Zelazko should relax and enjoy the moment – just as he was now.

  He released another salvo of chain-fire after the loyalists, humming merrily to himself as he pursued them deeper into the complex.

  Assisted by Actis’ augurs, Norroll led the eradicant through the winding labyrinth of the fortress’ sub-complex. The entire level was blacked out, forcing the Scions to rely upon their night filters to see. They dared not activate their monoscopes for fear of making themselves more obvious to the Iron Warrior, though the darkness did not appear to impede him in the least.

  The blast door to the central control room lay partially open, the mechanism operating it having apparently failed at some point in the past. Fennech grasped the edge of the door, wrenching at it with powerful hydraulic fingers in an attempt to close it behind them, but the enormous hatch was stuck fast. The enemy’s ponderous tread echoed down the corridor, forcing him to abandon his endeavour. The doorway, too narrow for the Traitor Astartes to fit through, was hopefully impediment enough.

  Another sound carried down the hallway – a low, rhythmic bass throb, barely audible above the thudding footfalls following them. It was an unidentifiable, uniquely strange sound, reminiscent of the chugging of a faulty promethium combustion engine, that grew louder with the enemy’s approach.

  Norroll had the impression that the Adeptus Astartes was herding them, rather than trying to kill them outright, as another salvo roared from the chaincannon. Distorted by the Space Marine’s voxmitters, the bass hum began again.

  Norroll realised the hum was exactly what he thought it was – despite the absurdity of it, the Iron Warrior was humming to himself, his vox-speaker picking up and enhancing the low sound.

  ‘He’s enjoying this!’ Norroll exclaimed, suddenly incensed at the realisation. ‘We’re a happy diversion to him!’

  The control room was circular, maintaining enough work­stations to outfit an entire regimental staff. A large circular platform lay in the very centre of the room, approximately three and a half feet higher than the rest of the workstations that radiated out from the walls. They concealed themselves in the dark behind ancient graven lecterns of dark stone and waited. Rybak and Bissot flanked the door, while the rest of the eradicant arrayed themselves around the central platform.

  The humming stopped as the Iron Warrior and his formation of servitors halted outside the blast door. Slowly, the door ground open, groaning and juddering. Metal shrieked against metal, followed by the heavy pop and hissing crumple of bursting pneumatics as the Space Marine wrenched it open.

  Bissot opened fire, spraying the Iron Warrior with las-fire that stitched glowing divots across his armoured chest and shoulder. One of the servitors returned fire, fist-sized bolter shells splintering the desk she sheltered behind. The volley gunner threw herself out of the way, snarling as she crawled behind the shelter of another desk with her right hip lacerated by a detonating mass-reactive.

  Rybak rose from behind a desk, plasma gun at his shoulder, and narrowly avoided being cut in half by heavy bolter fire. Like Bissot, he dived for cover as the desk he sheltered behind was smashed to flinders.

  The Traitor Astartes climbed up onto the platform. His servitors ranged out to the far edges around him, covering the space where First Eradicant sheltered below. The ironclad menials opened fire at even the slightest movement from the workstations beneath them, the darkness no impediment to their enhanced vision as they forced the Scions to keep their heads down. As awkward and clumsy as the gun servitors’ movements initially appeared, they operated as one. Slaved to the will of the Adeptus Astartes, the constructs functioned with uncanny synchronicity, as if their master wielded their weapons with his own hands.

  Screened by the flawless perimeter of his servitors, the Space Marine carefully opened a steel panel next to the central command terminal. Entirely unperturbed by the Scions, he squatted down, chaingun angled towards the ceiling. He hummed to himself as he worked on something, daring the eradicant to brave his unblinking servitors. Lights flared across the console as nearby cogitator systems clattered back to life. The Traitor Astartes rose, carefully replacing the panel before tapping a series of commands onto a cogitator runepad with his left hand.

  Generators around the facility shuddered to life with knocking ticks, the whine of their dynamos increasing in pitch until it became a smooth, flat drone. An instant later, the lights kicked on across the entire level.

  The Scions recoiled, momentarily blinded by the glare as their optics cut out to clear their night filters.

  The Space Marine took his chaincannon with both hands and depressed the power stud, spinning up the barrels before raking a quick salvo across the desks below. Daviland and Traxel went prone as the hail of bullets shattered the desks above them.

  ‘I am impressed you made it so far,’ the Traitor Astartes said. ‘Exploiting the little gateways I left in my defences is not something many have been able to manage.’ He ripped off another burst, this time over Atebe’s and Akraatumo’s heads. ‘Surviving an Iron Warrior’s fortress for as long as you have is admirable.’ His steps thumped heavily across the raised platform. ‘I am curious – I have never seen servants of the False Emperor like you. Are you Solar Auxilia, or whatever passes for them in this benighted epoch?’

  Norroll glanced down at Actis’ readings. He had deployed the servo-skull into the upper reaches of the room before the Iron Warrior’s arrival to develop a comprehensive image of what they fought, and the Space Marine had thus far overlooked the construct. His vambrace scraped the ground as he scrolled through the augury data and one of the servitors opened fire, the heavy bolter shells missing the recon trooper by a hand’s span.

  The Iron Warrior sighed, a low, static-laden growl from his voxmitter. ‘I don’t expect you to answer,’ he said, strafing the tops of the desks. His servitors joined in this time, sending chunks of splintered stone and shattered cogitators spinning about the room. ‘Sometimes, the mystery is preferable.’

  ‘That’s it,’ Norroll whispered to himself. The servitor on the right side of the podium nearest the door and another on the opposite edge fired slightly out of sync with the others. It wouldn’t be immediately obvious, but Actis’ sensors detected a brief, exploitable lag.

  ‘Atebe, Rybak,’ Norroll called over the vox, ‘Actis has picked up a deficiency in the servitors nearest you. If I draw their fire, can you bring them down?’

  ‘Yes,’ Atebe answered.

  Rybak scoffed. ‘Certainly.’

  ‘Good. We move in–’

  ‘No,’ Traxel said. ‘Maintain position.’

  ‘Tempestor,’ Norroll protested. ‘I’ve analysed the data three times. Two of the servitors are damaged. There is almost half a second’s lag between when the first servitors start up and those two begin firing.’

  ‘And I stand to lose three Scions at once if things don’t go to your plan.’

  ‘Are we to hide behind these desks and wait for them to shoot us?’

  ‘No, we wait for them to run out of ammunition – which, if you haven’t noticed, they are squandering on intimidation.’

  As if to reinforce Traxel’s point, the Iron Warrior and his servitors opened fire again. Daviland grunted as a heavy round fragmented the stone lectern she sheltered beneath and burst against her left pauldron.

  ‘Atebe, Rybak… Moving in three. Two. One.’

  ‘Norroll…’

  Norroll leapt to his feet and sprang out from beneath the desk, almost immediately diving for cover once again as the servitors pivoted to open fire.

  Mass-reactives ploughed through the workstations above him, blasting overturned stone pews to flinders as they tracked him.

  Rybak jumped out of cover as the servitor nearest him pivoted after Norroll, bringing the plasma gun to his shoulder and taking aim in a single, smooth motion. He squeezed the trigger, releasing a plasma bolt into the side of the servitor’s ironclad skull. The construct’s head detonated like a bomb and Rybak ducked back beneath the desk, his plasma gun venting steam.

  Atebe leapt up on the opposite side of the room. The second servitor’s lifeless left eye filled the centre of her sight aperture. The high-powered las-round punched through its skull, halting its torrent of heavy bolter fire immediately. It tottered for a few seconds before collapsing heavily onto its back.

  Before she could duck back behind cover, the Iron Warrior raked chaincannon fire across her chest, kicking her backwards. She collapsed in a heap beneath the withering storm of shells.

  ‘You, again,’ the Space Marine grumbled.

  Norroll exploded forward, exploiting the gap in coverage left by the two destroyed servitors. He drew his monoblades, hurling himself at the Iron Warrior and latching on to the hulking legionary’s backpack. He sliced through the Reaper cannon’s power feed cable with his right blade, protected from the remaining servitors’ fire by his proximity to their master. Norroll braced himself against the Reaper cannon, seeking leverage to stab the other blade through the flexible armour beneath the Traitor Astartes’ right armpit.

  Before he could drive the blade home, the Iron Warrior hurled him off. The chaincannon crashed into Norroll’s sternum, sending him spinning over desks and through cogitators. The Space Marine levelled the Reaper and depressed the trigger, but nothing happened. Not wasting time pondering the problem, he launched himself at the stunned Scion, smashing desks aside as he powered forward.

  The plasma bolt struck the Iron Warrior in the left side of his chest. Fired on maximal power, the round punched straight through the Space Marine’s power armour, flash-cooking the flesh and organs beneath. Trapped by the war plate, the burst of pressurised steam within the Traitor Astartes’ body vented through the weak point under his left arm, blowing the limb free in a churning cloud of vaporised blood.

  Rybak ducked down beneath cover, plasma gun steaming, the last of its fuel spent.

  Even then, the Iron Warrior did not fall. Transhuman flesh and blood laboured to overcome the catastrophic harm that would have killed an ordinary man ten times over. The Traitor Astartes staggered but remained upright, roaring as he searched for the source of this affront.

  Fennech and Traxel were on him simultaneously, taking advantage of the chaos to slip inside the legionary’s defences. As the massed fire of the Tempestus Scions brought down the final two servitors, who remained mind-locked in place, Traxel struck at the wounded Space Marine from behind, his chainblade shredding through the soft armour on the Iron Warrior’s right hip and deep into flesh and bone.

  The Traitor Astartes snarled, backhanding the Tempestor with a vicious blow from his chaincannon. The strike hurled Traxel through the air, sending him sliding on his stomach off the platform and into the shattered remains of the workstations below.

  The Iron Warrior’s targeting eyepiece exploded, snapping his head back as a point-blank round from Fennech’s bolt pistol struck home. The wounded Space Marine rolled with the strike, using the weight of his heavy weapon as a counterbalance as he angled it towards the commissar.

  Fennech blocked the chaincannon with his crackling power fist. The impact shattered the Reaper with a thunderclap of energy, sending the weapon’s multiple barrels and furnishings exploding free of the Iron Warrior in a flash of arcing white sparks and twisted barrels that took his lower arm with it.

  Even the loss of his second arm below the elbow did not seem to deter the furious Adeptus Astartes, who struck out at the commissar with a vicious kick, every mote of the transhuman warrior’s being channelled into offensive action. Fennech dodged backwards, losing his cap as he narrowly managed to avoid a strike that would have staved in his sternum.

  The Traitor Astartes staggered as Traxel clambered back onto the platform, repeatedly firing his plasma pistol at the Space Marine. The chaincannon’s backpack-mounted ammunition hoppers ignited in a fireball, tearing the pack free of its moorings and pitching the Iron Warrior forward.

  In the absence of the mini-reactor powering his armour, the crippled Space Marine struggled beneath the weight of his own war plate. He stumbled, attempting to right himself on legs suddenly transformed into dead weights, without the benefit of arms for counterbalance.

  Lightning arced from Fennech’s power fist as he drove it into the Iron Warrior’s head, smashing it against the snarling brass faceplate with an explosion of dazzling force. The arcane technologies at work within the gauntlet crumpled ceramite and adamantine like parchment as the Traitor Astartes’ skull burst.

  Headless, the armoured corpse pitched backwards with a heavy crash, buckling the surface of the platform beneath its weight.

  Fennech retrieved his cap, carefully dusting it off before setting it back on his head.

  ‘There is nothing as wretched or hated, in all the worlds, as a traitor,’ he stated to the disarticulated corpse at his feet. ‘May your faithless soul languish eternally.’

  Below, the eradicant picked themselves up from the ruins of desks and administrative equipment, shrugging free of their cover as they verified the servitors were indeed dead. Norroll grunted as he rolled over and sat up. Thanks to the vitalotox, he still felt little enough in the way of pain – probably a good thing, considering his body was not moving as it was supposed to.

  Daviland rushed to where Atebe had fallen, any concern for her own wounds rendered secondary to the well-being of her squadmates. The sniper struggled for breath, her armour rent across her chest from pauldron to pauldron. The stream of high-powered bullets from the Reaper chaincannon had churned a swathe of the ablative top layers to powder, but the plates beneath had held. Atebe bled from beneath both her arms, superficial wounds that had scorched through the ballistic cloth and creased the flesh beneath. Daviland’s cursory examination yielded that several of Atebe’s ribs were broken, but there was no major internal damage.

  A flatline droned across the Scion’s slates monitron. ‘Can you manage?’ Daviland asked, helping the sniper sit up.

  Atebe nodded. ‘Go. I can manage,’ she said breathlessly.

  ‘Remember the Rotes for Clear Mind and Sound Body,’ Daviland advised as she rose. ‘Quisse and Phed,’ she said urgently as she rushed past Traxel.

  The Tempestor nodded, his attention fixed on the Iron Warrior’s corpse. ‘Bissot, Durlo, go with her.’

  ‘Salenna, wait,’ Bissot called as she and Durlo rushed after the medicae-adept.

  ‘The Three-Hundred-and-Seventeenth is reporting that they destroyed the drop pod, Tempestor,’ Akraatumo stated. ‘They’ve restored comms with the Hundred-and-Thirty-Ninth. Foretrak’s defence systems are wholly inoperative, and air defences are offline as well.’

  Traxel nodded his acknowledgement again as he approached the Traitor Astartes’ remains. ‘Excellent shot, Rybak,’ the Tempestor said.

  ‘Thank you, Tempestor.’

  Norroll regarded Traxel quizzically – he was moving as stiffly as a servitor, his eyes looking at nothing but the massive armoured corpse.

  ‘Well done, Tempestor,’ Fennech said, the faintest smile stretching his thin lips as Traxel approached. ‘There are few who can boast of surviving an encounter with one of the Traitor Astartes, and fewer still who may claim to have done so twice.’

  Traxel made no reply. He stopped next to the Iron Warrior, staring at the heavy plastron that curved protectively over the traitor’s chest and abdomen. The Tempestor’s left hand, the aug­metic, trembled slightly as it gripped his plasma pistol. Sheathing his chainsword, he reached up with his right hand and raised his helm’s optics before unsealing his respirator. He lifted off his helmet and dropped it ­heavily to the floor. The Tempestor’s dusky skin was ashen and sheened with sweat, his dark eyes alight with a furious hatred behind the creases of dark, puffy flesh ringing them.

  Traxel’s plasma pistol flashed up. He fired three bolts into the Iron Warrior’s corpse in quick succession before the trigger clicked empty.