Rules of Engagement
Graham McNeill

	He wanted to weep, but the last two years had turned his heart to stone. Too much had been asked of him, too much had been lost, and he had no more sorrow left. Brothers forsaken, a world of Ultramar burned and the golden dream of galactic unity reduced to ashes. Such a singular moment in history should be mourned. It demanded tears, a rending of clothes, a tearing of hair, or, at the very least, an outburst of primal rage.
	He indulged none of these cathartic releases.
	If he allowed tears of sorrow to fall, they might never stop.
	The interior of the Arcanium was a twenty metre square cube with an arched doorway in each wall, softly lit by thick candles held aloft in iron sconces worked in the form of eagles and lions rampant. The floor was of a dark slate, and its walls were formed from bare timbers, polished and worked smooth by a plane wielded by his own hands. He remembered finding refuge here many years ago, when the incessant bickering between the senators of Macragge had become too unbearable for a boy who thrived on action and excitement.
	That boy was gone now, drowned in the blood of Konor’s murder and the greater tide of slaughter he had unleashed in the wake of that treachery. Once he had called it justice, but the passage of time gave him the perspective to recognise the truth of his motivation. Revenge was never a worthy reason to send men to war, and he had resolved to never again fall prey to its seductions. Having identified the flaw, he had taken steps to purge himself of that weakness, and the execution of Gallan had been the last time emotion guided his hand.
	He returned his attention to the book before him, hearing the bustle of the fortress beyond the lovingly crafted walls of his private sanctum. Once this place had been remote from any petitioners, built hundreds of miles from the nearest settlement, but its isolation was now a thing of the past. Acres of marbled walls, glittering geodesic domes, soaring towers and perfectly proportioned structures surrounded it. An entire library had been raised up around the chamber, and though the architects and mathematicians had begged him to consider the harmonious geometry of the golden mean inherent within their plans, he had refused to allow the Arcanium to be demolished.
	He wanted to smile, recognising that perhaps Gallan’s execution hadn’t quite been the last time emotion had played a part in his decision-making process after all. But the smile refused to come, and in the face of all that occupied his thoughts now, his determination to hang on to this fragment of his youth seemed a wilfully petty thing. 
	Seated at a heavy table of dark wood that filled the centre of the chamber, he read the words he had just written in the enormous tome before him. Its spine was a metre long and thick enough to enclose a book fully thirty centimetres deep. Brilliant gold leaf edged the warm leather binding, and the pages were pale vellum that still carried the scent of the beast from which it had been cut. Tightly wound script filled the leftmost page, each letter precisely formed and arranged in perfectly even lines of text.
	The work was progressing, and every day brought him closer to completion.
	It was to be his greatest work, his Magnum Opus, the undertaking for which he would be forever remembered. Some might consider such sentiment to be vanity on his part, but he knew better. This was a work that would save everything his gene-father had tried to build. Its teachings would form the foundation of what was needed to weather the coming storm. Selflessness, not pride, guided his hand as he set down decades of accumulated wisdom, each chapter and verse a fragment of his biologically encoded genius, each morsel of imparted knowledge a building block that would combine to form a work immeasurably greater than the sum of its parts. 
	In the wake of the devastation unleashed on Calth, the Legion was looking to him for leadership more than ever. His warriors had suffered a grievous blow to their pride, and desperately needed to see their primogenitor. Helots brought petitions for audiences from his Chapter captains every day, but this endeavour was too important to grant such requests.
	They did not understand why he sequestered himself away from his sons, but they did not need to understand. All that was required of them was obedience, even when his orders made no sense and seemed as heretical as those that had set the galaxy ablaze.
	In all his years of service to his gene-father, he had never faced so terrible a choice.
	The Imperium was lost. Everything he knew told him so, and this betrayal was the one thing that would save the dream at its heart from extinction.
	The body of the Imperium was dying, but the ideals of its foundation could live on.
	His father would understand that, even if others would not.
	Roboute Guilliman wrote two words at the top of the right-hand page: words of treachery, words of salvation. Words to herald a new beginning.
	Imperium Secundus.
	Engagement 94
	His name was Remus Ventanus of the Ultramarines 4th Company, and he was a traitor.
	This sat ill with him, but there was little he could do to change it. The orders came directly from the primarch, and if there was one thing drilled into Ultramarines from the earliest days of their training it was that orders were always obeyed, no matter what.
	Intermittent flashes lit the mountains of Talassar with a scratchy, pale glow as bright streamers of fire dropped burning traceries like phosphor tears across the night sky. The retreat from Castra Publius had been long and gruelling, made more so by the relentless, dogged pursuit of their attackers. Like razorfins with the scent of blood in the water, the warriors of Mortarion never gave up, never let up the pressure and never, ever, stopped attacking once battle had been joined.
	It was a trait Remus had once admired.
	He had no idea how the war across the rest of Talassar went. All he knew was what the planners in the grand strategium fed him through his helmet, but they jealously guarded their secrets and were miserly when it came to distributing information.
	Eighteenth Company had held Castra Publius to the last man, long enough for the remainder of the Ultramarines to escape, falling back to pre-prepared positions raised by helots, Talassar Defence Pioneers and the monstrous construction engines of the Mechanicum. Those engines were proving key to their strategy, and Remus was grateful the primarch had seen fit to demand a permanent presence of the Martian priesthood on each world of Ultramar before the Red Planet had fallen to the Warmaster’s allies.
	Remus pushed himself to his feet and lifted his bolter from the rocks beside him. He ran through the readiness checks and snapped home the safety, the action so ingrained it was automatic. Just like everything a warrior of the XIII Legion did. He clamped the weapon to his thigh and looked out over the landscape around him.
	The mountains of Talassar snaked across the planet’s single continent like a buckled spine, each vertebra a gnarled peak and each gap a series of corrugated valleys with hairline fractures that penetrated deep into the rock to form hidden valleys, dead-end grabens and narrow gorges whose floors never saw sunlight. It was terrain to favour the defenders, and every scenario of invasion relied upon the mountainous bulwark and its linked fortresses.
	What those scenarios hadn’t counted on was a foe as implacable as the Death Guard.
	An angled wall of compacted rubble and rapid-setting rockcrete sealed this particular valley with a series of fortified redoubts and strongpoints. Remus was no stranger to the speed and completeness with which the Mechanicum could sculpt landscapes, yet the sight before him was still incredible.
	The valley had grown wider and deeper, its flanks blasted, excavated, drilled and dug out to form the linked series of earthworks that spanned its width. He and the 4th Company had deployed from here less than half a day ago, when the valley floor had been smooth and empty, and the black, volcanic walls were coloured by hardy lichen and projecting evergreen firs. All that was gone; the once verdant highland valley now resembled a quarry that had been worked for decades. Talassar Auxilia units manned artfully wrought redoubts formed from pre-stressed slabs, and Ultramarines heavy guns occupied revetments that hadn’t been there ten hours ago.
	It had been a hard retreat, with the forward units of the Death Guard harrying them every step of the way. Remus had balked at the idea of allowing the enemy to maintain the initiative, but the new doctrine required them to give ground. 
	Gathered in carefully placed groups, the three thousand Legiones Astartes of the 4th Company took their rest behind the high wall, and Remus threaded his way through them. He shivered as he passed beneath the shadow of one of the Mechanicum’s construction engines. It towered over him, longer and wider than the Gallery of Swords on Macragge; and set the earth trembling with the low bass note of its mighty engine core. Its enormous bulk was a dusty ochre colour, studded with weapon mounts, striped with hazard chevrons and stamped with monochrome representations of the Cog Mechanicum.
	His warriors were deployed behind the wall, each squad placed exactly according to the new tactical doctrines recently put in place. As part of a radical shake-up of the way the Legion was organised, a series of new regulations and orders of battle had come down from the Fortress of Hera, imposing strict guidelines upon how each warrior and squad operated within the Legion as a whole. It felt strange to devolve command autonomy to a set of predetermined strictures, but if there was anyone who could devise a tactical doctrine to meet any foe and any situation, it was Roboute Guilliman.
	He saw Sergeant Barkha at the steps leading to the fighting platform, listening to the reports from the 4th Company Scouts on the cliffs above. Of all the warriors of the Ultramarines, these warriors had the toughest time adapting to imposed rules, but such was the comprehensive nature of their new operating procedures that even the 4th Company’s irascible Head Scout, Naron Vattian, was finding it near impossible to find fault with them.
	‘Any sign yet, sergeant?’ asked Remus.
	Barkha turned and hammered his fist to his chest, the pre-Unity salute. It felt strange to see his sergeant make such a gesture, but Remus supposed it was more appropriate than the aquila, given that they were now traitors.
	‘Lots of activity around Castra Publius, but no sign yet that they’re on their way,’ said Barkha, his hands now ramrod straight at his side, as though he stood on a parade ground instead of a battlefield.
	‘We’re not on Macragge, sergeant,’ said Remus. ‘No need for such arch formality.’ 
	Barkha nodded, but his stance remained unchanged.
	‘Standards, captain,’ replied the sergeant. ‘Just because we’re on a war footing is no reason to let them slip. That’s how this mess began after all. Standards slipped. Won’t happen on my watch.’
	‘Is that a rebuke?’ said Remus, wiping the coarse black dust of the mountains from the azure surfaces of his battle-plate.
	‘No, sir,’ replied Barkha, staring at a point over his right shoulder. ‘Simply a fact.’
	‘You’re absolutely right, sergeant,’ said Remus. ‘If only the Warmaster had been attended by a naysmith like you, then this could all have been avoided.’
	‘I was being serious, captain,’ said Barkha.
	‘So was I,’ replied Remus, climbing the steps to the ramparts and casting his gaze down the mountains. Barkha dutifully followed him and stood at his side, ready to enact whatever order he gave. Though Remus couldn’t see them, he knew Death Guard units were probing the lower valleys, seeking the weakness in the Ultramarines defence line.
	‘I’m no engineer, but even I can see we won’t hold this wall,’ said Barkha.
	‘Why do you say that?’
	‘They’ve built the wall too far out. The narrowest part of the valley is behind us.’
	‘And?’
	‘That’s made the wall too long,’ said Barkha, as though unable to comprehend how his captain couldn’t see what was so obvious to him. ‘We don’t have enough warriors or heavy guns to repel a serious assault.’
	Barkha gestured over his shoulder. ‘Yaelen’s Gorge is to the south, but it’s too narrow to move heavy armour at any speed. Castra Maestor blocks the Helican Stairs to the north. This is the only viable route through our line, and the Death Guard will see that swiftly enough.’
	‘All of what you say is true, sergeant,’ said Remus. ‘Do you have a point?’
	‘Of course. It’s almost like you want them to attack here. What I don’t understand is why we are letting them when we should be taking the fight to them.’
	‘The Death Guard advance like a surge tide,’ said Remus. ‘If we meet them head on, their strength will sweep us away. But we pull back, drawing them ever onwards until they are thin and spent. Then we will strike them.’
	‘This is your plan?’
	‘No,’ said Remus. ‘It is our strategy as decreed by the primarch’s writings.’
	‘Permission to speak freely, captain?’ asked Barkha.
	‘Granted.’
	‘Are we really going to play this out basing our tactics on a book?’
	‘The primarch’s book,’ Remus reminded him.
	‘I know, and I mean no disrespect by these questions, but can any book – even one written by a primarch – cover every tactical eventuality?’
	‘I suppose we are about to find out,’ said Remus, as he heard chatter over the vox.
	Death Guard units were moving into the lower reaches of the valley.
	‘Stand the men to arms, sergeant,’ ordered Remus.
	‘Aye, captain,’ said Barkha. He saluted and turned to get the 4th Company moving.
	Remus Ventanus stared off into the distance, seeing a glitter of fires from further down the mountains. Castra Publius was gone, Ultramarines were being lost and the Death Guard were coming to destroy them.
	How had it come to this?
	The Death Guard attacked fifty-two minutes later, a brutal assault spearheaded by heavy armour and Dreadnoughts. It was a mailed fist, calculated to bludgeon the defenders into insensibility before the follow-up punch slammed home to complete their destruction. Mechanised infantry squads rumbled forwards in the wake of olive-painted Land Raiders that hurled incandescent bolts at the defenders. Disciplined phalanxes of warriors armoured in the same livery deployed from the armoured transports and began their inexorable advance upon the Ultramarines position.
	Laser fire and bolters hammered the advancing warriors, punching holes in the advance but slowing it not at all. What little artillery they had dropped specially manufactured munitions into the enemy ranks, felling enemy squads in shrieks of light and sound. Enemy Dreadnoughts waded into the fight, weaponised arms sawing through the defenders with machine-like precision and lethality.
	Remus saw an entire squad of Ultramarines put down by two Dreadnoughts working in concert, and bellowed to his one remaining heavy weapons team to take them out. A trio of missiles leapt towards the Dreadnoughts, and one fell silent as it was struck in the flank by two warheads. The second was dealt with moments later as a multi-melta scored a direct hit on its sarcophagus.
	These were fleeting victories, bright moments in the face of overwhelming odds. The Death Guard fought like machines, driving forwards with the unthinking, unfeeling ardour of something soulless and mechanical. Remus was a warrior, a gene-crafted killer of superlative ability, but he had been created to be so much more than that. He took pride in his abilities as a warrior, relishing the chance to match his skill against another, but to see the Death Guard at war was to face an opponent to whom war was simply attrition.
	But Remus had no intention of dancing to the Death Guard’s war drums.
	Tactical feeds flickered and scrolled on his visor, casualty rates, kill-ratios, projected outcomes, and a dozen other battlefield variables. The flow of information would have left even an augmented Imperial Army Tacticus overwhelmed, but Remus’s genhanced cognitive architecture processed it in the time it took to blink.
	As the Death Guard regrouped for another assault on the walls, Remus’s eidetic memory accessed the parameters of battle as contained in the primarch’s tactical schematics. He found a match, following the logic path through its predetermined courses of action. Now was the time to pull back.
	Remus clamped his bolter to his thigh and issued the withdrawal order, one of two dozen permitted options available to him. With smooth precision, the Ultramarines began falling back by squads as the Talassar Auxilia filled the killing ground before the wall with las-fire. The Mechanicum engine, though not designed as a war machine, was nevertheless equipped with a fearsome array of defensive weaponry. As its enormous treads ground it away from the battle, the barking roar of its close-in guns ripped overhead, the sound strangely flat and without the usual percussive banging of massed bolters. Artillery pieces launched a last volley over the walls before turning and racing up the winding road through the mountains.
	Remus turned and dropped from the wall, joining Sergeant Barkha and the depleted ranks of his command squad. Ithus, Helika and Pilus were gone, which left his squad dangerously under strength, but the primarch’s writings had considered such an eventuality, and Remus acquired replacements from those squads who had come through the fighting unscathed.
	Behind them, the Death Guard finally reached the wall, forcing their way over it as the defenders made their escape. As the Ultramarines crested the ridge behind the wall, Remus sent a coded burst transmission to the Mechanicum adept in the gargantuan construction engine. Seconds later, a controlled series of detonations brought down the valley walls in a thunderous avalanche. It was little more than a delaying tactic. The Death Guard would break through before long, but it was enough for now.
	Barkha nodded to him as they retreated into the mountains.
	‘We’re running out of room,’ said Barkha. ‘You think we’ve done enough to break them against the walls of Castra Tanagra?’
	Remus didn’t answer right away. The tactical plots of kill-to-casualty ratios were scrolling down his screen. It made for grim reading, but they were still within the parameters set by the predicted conditions of the engagement. Overviews from the grand strategium filtered through the tactical information, revealing the extent to which the Death Guard had been bled white by constantly hammering the Ultramarines fortifications.
	‘It looks like it,’ he replied. ‘The other Chapters have done well.’
	‘Not as well as us, though?’ asked Barkha.
	‘No, not as well as us,’ said Remus. ‘No one outdoes the Troublesome Fourth, eh?’
	‘Not on my watch,’ agreed Barkha.
	Remus liked the heart his sergeant displayed, pleased to hear such proud aggression in the warrior’s voice. It seemed the primarch’s purely doctrinal approach to war was holding up to the vagaries of battle.
	But this was simply one fight, and one opponent of many ranged against them.
	The real tests would come later.
	Engagement 136
	The holo-pict projected above the glossy surface of the plotter cast a stark light around the grand strategium. It folded sharp shadows around the gleaming walls and bleached deeply tanned faces of colour. The air was thick and close, redolent with the toxic oils and caustic unguents smouldering in the Mechanicum’s censers. It smelled of engine oil mixed with at least a dozen poisonous elements, and though it was Mechanicum witchery, it was certainly effective. The Legiones Astartes endured these effluvia without effect, but the mortals within the grand strategium coughed and rubbed eyes that constantly streamed with tears.
	Remus Ventanus didn’t know if they were tears engendered by the petrochemical irritants in the burners or the sight of so beautiful a world being destroyed. A measure of both, he surmised.
	He stared at the desolation of Prandium and wanted to weep. The most beautiful world of Ultramar by any reckoning, its wondrous forests, sculpted mountains and shimmering lakes were either burning or wreathed in smoke and choked with pollutants.
	Never afraid of extreme measures, Angron had let slip his World Eaters in the most vicious way imaginable. Remus had once heard his primarch say that Angron’s Legion could succeed where all others would fail because the Red Angel was willing to go further than any other Legion, to countenance behaviour that any civilised code of war would deem abhorrent. 
	Seeing what had been done to Prandium, Remus understood completely.
	This was no honourable war, this was butchery and destruction embodied. The primarch’s great work could surely never have contemplated war with so terrible a face.
	The World Eaters had dropped on Prandium after a punishing saturation bombardment that levelled most of its great cities and set the world ablaze from pole to pole. In truth, there was little worth saving. Millions of people were dead and the detonations of volatile munitions had polluted the atmosphere and seas for millennia to come.
	Yet Prandium was still valuable. Its orbital track passed close to the coreward jump-point, meaning that whoever controlled Prandium could control entry to Ultramar. Even if Prandium was reduced to a barren, lifeless rock, it was still a world of Ultramar, and nowhere trod by Roboute Guilliman would be surrendered without a fight.
	Coming so soon after the devastation wrought on Calth’s sun, it seemed to Remus that their worlds were being torn apart piece by piece. Like an ancient, crumbling standard removed from its stasis vault in the Fortress of Hera, the warp and weft of Ultramar’s fabric was coming undone. Alone among the many savage assaults tearing at the Ultramarines empire, the invasion of Talassar had been repulsed. Driven on by their apparent success, Mortarion’s warriors had over-extended their forces and been left dangerously exposed when they finally hurled themselves at the mountain fastness of Castra Tanagra.
	Elements of the 4th, 9th and 45th Companies had garrisoned the fortress, and as the Death Guard attacked, the encircling horns of the 49th, 34th, 20th and 1st Companies drew in and completed the destruction. It had been an uplifting moment, yet Remus could not see how something similar could be done here.
	Surrounding the plotter, their faces grim and carved from granite, were the captains of fourteen of the Ultramarines battle companies, together with their lieutenants, senior sergeants and savants. Battle-logisters pumped information into the plotter, real-time strategic data that depicted a world torn apart by war.
	A world dying before their very eyes.
	‘Fifth Company manoeuvring into position,’ said Captain Honoria of the 23rd. ‘Seventeenth moving in support.’
	‘Enemy forces engaging the Twenty-fifth,’ said Urath of the 39th.
	‘Eastern flank of Adapolis is folding,’ commented Evexian of the 7th. ‘They’ll break through in a matter of hours. I’m ordering the Forty-third and the Thirty-seventh to fall back.’
	‘Are the Thirteenth and Twenty-eighth in position to meet the northern push?’ asked Remus.
	‘They are,’ confirmed Honoria. ‘World Eaters Third, Fifth and Ninth are pushing hard at the borders of Zaragossa Province. If we don’t send in reinforcements, we could lose the entire western flank.’
	Remus circled the plotter with his hands behind his back, looking for some flaw in Angron’s battle plan. As senior captain in the grand strategium, he had overall command of Ultramarines forces on Prandium, a level of command he had never before held, but the primarch himself had made the appointment.
	Why had he been chosen? There were others in the grand strategium with more experience. Since Talassar, Remus and the 4th Company had fought dozens of smaller actions, each time emerging victorious, but each of them had been a company-level engagement, with no more than a few thousand warriors at his command.
	This was another strata of warfare entirely. To command the defences of an entire world was something that Remus had, of course, trained for but never actually done. The primarch’s teachings were indelibly etched on his mind: options, variables, parameters, action paths, outcome responses and a thousand detailed plans covering every possible eventuality of war.
	It had worked on Talassar, and Remus had to trust that it would work here.
	He stepped up to the tactical plotter and took in the strategic overview in a heartbeat. The motion of armies, divisions and cohorts – a thousand elements of planetary warfare – was a spider’s web of furious advances, flank marches, brutal battles and encirclements. At Pardusia, the 19th Company had been all but destroyed, and the World Eaters had powered north through the wastelands of what had once been ornamental pasturelands where wild horses had roamed freely and rare flora, virtually extinct in Ultramar, had again bloomed in glorious bursts of kaleidoscopic colour.
	The assembled captains glared at him, resentful at sending their brothers to die following orders that broke the cohesion of the Ultramarines defence lines. Arcs and lines of blue snaked across the map at random, each one an isolated bastion of Ultramarines, Defence Auxilia and requisitioned Imperial Army units.
	‘What are your orders, Captain Ventanus?’ demanded Captain Honoria.
	Remus stared at the map, feeding the current situation through the filters of the primarch’s work. Orders presented themselves to him, but they made no sense. He checked his conclusions again, knowing they were correct, but checking them anyway.
	‘Order the Twenty-fifth and the Seventh to realign their frontage,’ ordered Ventanus. ‘The Seventeenth is to halt and hold position.’
	‘But the Fifth,’ protested Urath. ‘They’ll be cut off without the Seventeenth covering their flank.’
	‘Do it,’ said Remus.
	‘You will condemn those warriors to die needlessly,’ said Honoria, gripping the side of the plotter tightly. ‘I cannot stand by and watch you lose this world and our Legion’s best and bravest with such insanity.’
	‘Are you questioning my orders?’ asked Ventanus.
	‘You’re damn right I am,’ snapped Honoria, before remembering himself. The captain of the 23rd took a deep breath. ‘I know what you did on Calth, Remus. Damn it, we all respect you for that, and I know you have the primarch’s ear. He has his eye on you for great things, I know that, but this is madness. Surely you must see that?’
	‘Question my orders and you question the primarch,’ said Remus softly. ‘Is that really a stance you wish to take, Honoria?’
	‘I question nothing, Remus,’ said Honoria guardedly. He swept his hand out to encompass the disastrous tactical situation on the projection of Prandium. ‘But how can those manoeuvres halt the World Eaters? The Red Angel’s butchers are gutting Prandium, and you are helping them to do it.’
	Remus held his tongue. For all that he agreed with Honoria’s sentiments, he had to trust that the primarch knew what he was doing. To try and understand the workings of a mind crafted by the genetic mastery of the Emperor was as close to unattainable as it was possible to be. The leaps of imagination, intuition and logic the primarch of the Ultramarines could make were unreachable to anyone save another primarch. And even then, Remus doubted any of Roboute Guilliman’s brothers could match his grand strategic vision.
	Yet what he had devised and passed down to them would only work if every cog in the machine was turning in the same direction. Honoria, for all his courage and honour, was twisting the machine’s workings. And that couldn’t be allowed. Not now.
	‘You are relieved of command, Honoria,’ said Remus. ‘Remove yourself from this post and have your lieutenant step up.’
	‘Ventanus, wait–’ began Evexian.
	‘You wish to align with Honoria?’ said Remus.
	‘No, Captain Ventanus,’ said Evexian with a curt bow. ‘But even you must admit that your orders appear somewhat… contradictory. You know this, I can see it in your eyes.’
	‘All I need to know is that my orders bear the authority of the primarch,’ said Remus. ‘Do any of you believe you know better than our progenitor? Can any of you say that you have a better grasp of the nuances of war than our sire?’
	Silence provided Remus with all the answer he needed.
	‘Then carry out my orders,’ he said.
	Prandium burned. Smaller Ultramarines icons winked out as they were destroyed, and the angry red icons of the World Eaters slowly broke apart like ripples of blood. No part of Prandium was left unscathed. The beautiful wild woods of the southern provinces were ashen, atomic wastelands, the crystal mountains of the east irradiated with toxic fallout that would take thousands of years to dissipate. Glorious cities of soaring gold and silver marble had fallen to ruin, pounded to rubble by orbital barrages that wiped them from the face of the world as if they had never existed.
	What had begun as a worldwide conflict had degenerated into a thousand or more scrappy brushfire wars waged between isolated battle groups. Ultramarines forces fought within a few miles of one another, but might as well have been on different worlds for all the support they could provide to one another.
	Remus felt as though he was sinking fast, already regretting his decision to remove Honoria from the command echelons of the grand strategium. Hadn’t he spoken of the value of a naysmith with Barkha? Didn’t every leader need a voice of dissent at his ear to force him to question his decisions?
	He searched the tactical plot for any sign of hope, wondering where he had gone wrong. What could he have done differently? What aspect of his primarch’s teachings had he failed to heed? He had reacted to every development with a rigorous application of the new doctrines, yet Prandium was on the verge of being lost forever.
	‘Push the Thirteenth forward,’ he said, as automatic memory called up yet more of the primarch’s lessons. ‘Bolster the Seventeenth, and order the Eleventh to reform to flank the World Eaters advancing on Thardonis. Advance to contact and pin them in place.’
	‘So ordered,’ replied Urath.
	‘Order the Eighth Battle Group to withdraw to the borders of Ixian Province. Mechanicum units to cover and pioneers to establish temporary fortifications,’ said Remus as yet more tactical variables fed into his precise recall. A pattern emerged, and Remus began to appreciate just how tenuous the World Eaters position was. It had cost blood and lives to bring them to this point, but only now did Remus see how delicately balanced this grand strategy had been.
	‘To win the greatest victory, one must take the greatest risks,’ the primarch had told him on the rad-wastes of Calth.
	‘You never take risks,’ countered Remus.
	‘Not that you would know,’ replied Guilliman.
	As the myriad situational variables displayed on the plotter flooded into the processing centres of Remus’s consciousness, the answers and manoeuvres required leapt to the forefront of his brain. He had heard it said that the greatest generals were those who made the fewest mistakes, but that was nonsense of the highest order. The greatest generals were those who planned for every eventuality and knew exactly how their foes would fight. Seeing the breathtaking beauty and complexity of the stratagems unfolding in his mind, he knew without a doubt that Roboute Guilliman was just such a general.
	The words virtually said themselves, using him as their conduit to life.
	‘Order Battlegroup Ultima to realign its frontage along the River Axiana,’ he said. ‘Ninth and Twenty-fifth to alter the direction of their advance. North-east to grid reference six-nine-alpha/eight-three-delta.’
	The captains followed his orders without question, but Remus wasn’t done. Orders poured from him, each one spat like a poisoned dart into the heart of the enemy commander. His subordinates could barely keep up with him as he sent manoeuvre orders into the field with breathtaking rapidity. Confusion lit every face, but as the worldwide stance of the Ultramarines armies began to realign and enact Remus’s orders, he watched those same faces transform into expressions of wonderment.
	In the centre of the Praxos Territories, a cluster of red icons, representing one of the main World Eater battlegroups, now found itself surrounded on all sides as previously isolated Ultramarines units merged and swung around like closing gates to trap it within a deadly killing zone. Within minutes those icons were winking out as the combined firepower of three Ultramarines battle companies flensed the region with artillery, massed bolters and overlapping fields of fire from cunningly positioned Devastators.
	All across Prandium, World Eater cohorts were suddenly surrounded and cut off from one another as their hot-blooded aggression pushed them straight into the Ultramarines guns. The effect was akin to a million dominos ranked up in seemingly random patterns that tumbled together to create a masterpiece of kinetic energy at work. Ultramarines companies that had been in full retreat swung around to link with their brothers to seal the World Eaters in deadly traps from which there was no escape.
	Like the most graceful ballet, the Ultramarines danced to the tune of Remus’s commands, working together in flawless harmony: an elegantly and perfectly designed killing machine. One by one, the red icons of the invaders winked out, while those of the Ultramarines remained a steady blue. Casualty indicators began dropping, until eventually falling to zero. And the World Eaters continued to die.
	Within an hour, the battles were over and Prandium was saved.
	‘I don’t believe it,’ whispered Urath as reports of secure battlefields chimed in from all across the ravaged world.
	‘It doesn’t seem possible,’ breathed Evexian. ‘So fast, so merciless.’
	In truth, Remus was having a hard time believing the end had come so swiftly. It was one thing to have trust in the primarch’s vision for his great work, quite another to see it in action.
	‘What’s our operational effectiveness level?’ asked Remus.
	His captains hurried to collate the information, filtering in reports from the field, casualty reports, ammo expenditure levels and unit degradation ratios. Reports streamed across the plotter, a few in red, fewer in orange, but the majority in a healthy green. Urath summed up the incoming flow of information, but Remus needed no interpretation of the data, the visual results were clear enough.
	‘Seventy-seven per cent of units in the field report immediate battlefield effectiveness,’ said Urath. ‘Eight per cent are at minimum or unsafe levels of readiness, and a further thirteen per cent are at dangerous threshold levels of unit effectiveness. Only two per cent are combat ineffective.’
	‘If I hadn’t seen it for myself…’ said Evexian, voicing the thoughts of them all.
	‘And this all came from the primarch’s work?’ said Urath.
	‘Did you ever doubt it?’ asked Remus.
	‘Damn me, but I wondered for a moment, Remus,’ replied Urath, wiping the sweat from his brow. ‘Reprimand me if you must, but I feared Prandium was lost. Along with much of the Legion.’
	‘Prandium might as well be lost,’ said Evexian bitterly. ‘Look at what those murderous bastards did to the Fair Maiden of Ultramar. How could any planet recover from such an ordeal?’
	‘Worlds of Ultramar are stronger than most, Evexian,’ said Remus, letting out a long breath and smiling at the victory he had just won. ‘Prandium can recover from this and bloom even more beautiful than before. Trust me, it would take more than Angron’s butchers to snuff out her radiance.’
	Engagement 228
	‘I don’t like this,’ said Sergeant Barkha. ‘Feels like we’re flying in a rations can. I could spit through this fuselage.’
	‘You can spit acid,’ Remus reminded him. ‘There aren’t many hulls or fuselages you couldn’t put a hole in with your saliva.’
	‘You know what I mean.’
	‘I do, but I wouldn’t worry. The Thunderhawk is just a stopgap design. It won’t be around for long.’
	‘Good,’ said Barkha, looking around the crude, factory-stamped interior of the rolling gunship. Its metal ribs were exposed and the wiring guts of the aircraft were visible in tag-tied bundles of cabling that snaked from one end of the boxy fuselage to the other. Ultramar was far from the centres of Mechanicum forge-worlds, and the XIII Legion had only recently taken delivery of a fleet of the new gunships. It irked Remus to see the hasty work, the shoddy specifications and unprofessional workmanship that had gone into the design and construction of the aircraft.
	No craftsman had deemed the design worthy of attaching his name, and Remus wasn’t surprised. This aircraft had all the hallmarks of servitor-assembled work, and that he was forced to trust his life to it didn’t make him feel any better. The stamp of the Mechanicum was acid-etched onto the bulkhead beside him, and Remus touched it for good luck.
	‘I saw that,’ said Barkha. ‘Superstitious are you?’
	The question was lightly asked, but Remus heard the warning behind it, the suggestion that his answer should be carefully chosen. Barkha would be quite within his rights to condemn his superior officer for conduct unbecoming an Ultramarines warrior. Even now, in the midst of a combat situation.
	Especially now.
	‘No, but I take reassurance from the fact they believe in this machine enough to mark it with their seal.’
	‘It’s probably the only thing holding it together,’ observed Barkha as the gunship banked around one of the sun-baked agri-silos of Quintarn. Spars of light from the vision blocks inset in the gunship’s fuselage swayed with the motion, and Remus felt something shear from the underside of the craft. Impact or system failure? His heart lurched as the gunship dropped, its wings passing within a metre of the silver-skinned silo.
	‘Target ahead,’ came a voice over the internal vox, sounding strained with the effort of holding the bucking craft steady. The timbre of the pilot’s voice told Remus exactly what the crew of this new craft made of it. A Stormbird had weight behind it, a solidity that made it a pleasure to fly and a safely cocooned means of transporting the killer Legionaries where they needed to be.
	Remus linked his helmet’s inloaders with the forward picters mounted in the gunship’s prow, seeing the pristine symmetry of Idrisia, one of the most central of the great agricultural hydropolis cities of Quintarn. Though given over to the utilitarian need for crops and industry, the city was still beautiful in its own way, with majestic towers, pillared hangars and marble-fronted meeting halls. Its street plan overlaid his vision, a masterful arrangement of function and aesthetic. Like most things in Ultramar, the primarch had turned his genius to the design and layout of its cities.
	Too bad he hadn’t turned it to the design of this gunship.
	Enemy strongpoints within the city were marked in red, and Remus saw how deeply they had sunk their fiery claws into the metropolis. City fighting was where this particular enemy excelled, with a propensity for weaponry that functioned best at short to mid range and could burn through cover as though it didn’t exist.
	This would be the most testing battle yet. The others had driven them to the point of defeat before the primarch’s great work had proved its worth. It had done so time and time again, in engagement after engagement. The 4th Company was by no means the only company now armed with their primarch’s incredible achievement. Even as the 4th Company’s aerial assault drew closer to its target, other companies were engaged in varied theatres of war with the enemy on Quintarn.
	But Remus felt sure that he and his warriors were the ones who would be watched the closest to see whether its teachings would embed in their psyche.
	In some circles they were known as the Troublesome Fourth, a company known for its daredevil actions, heroic follies and the personal bravery of its individual warriors. If the primarch’s work could be made to stick with the 4th Company, then it would stick anywhere. 
	And after Calth…
	Where the 4th Company led, the other battle companies followed.
	Remus switched out of his tactical view as the gunship juddered and the pilot jinked it to the side in a series of gut-wrenching evasion manoeuvres. The ready light above the forward assault ramp flashed from red to green and Remus slammed his palm against the gravity harness. The restraint lifted up and over his head, and he retrieved his bolter from the niche beside him. The Thunderhawk might be a ramshackle piece of junk, but it had cleverly designed stowage that at least made it functional.
	‘Fourth!’ yelled Remus. ‘Touchdown in fifteen seconds.’
	Thirty warriors filled the interior of the Thunderhawk, a force capable of meeting most enemy forces with a high degree of certainty that they would destroy it. Yet it felt strange to Remus to be going into battle without at least fifty warriors at his back. Warfare wasn’t about being fair or acknowledging the honour of your opponent, it was about crushing him into the dust with overwhelming force. Few enemies would survive the attention of fifty warriors of the Ultramarines.
	True, not many would survive an attack by thirty, but the point still rankled.
	Remus took his place at the front of the assault ramp, as the pitch of the gunship’s engines changed and the pilot brought it to a shrieking hover. The ramp dropped and the dry heat of scorched stone and hot metal filled the compartment. As powerful as those smells were, they couldn’t compete with the reek of synthetic fertilisers, chemical soil additives, the rich scent of turned earth and thousands of acres of crops. Remus charged out, his warriors forming up in perfectly aligned squads to either side of him. They spread out, keeping low to avoid the searing jetwash from the Thunderhawk.
	They were on a roof, seared black and reeking of burning propellant. Green-armoured bodies lay unmoving at the roof parapets, and Remus saw numerous missile tubes amid the clusters of the fallen.
	‘Good landing kills,’ said Barkha, following his gaze.
	‘True,’ replied Remus. He hadn’t felt the Thunderhawk’s nose guns firing, but supposed that was only natural. To effect an assault drop in a hot landing zone was a difficult and risky manoeuvre, but the guns of the Thunderhawk had efficiently cleared their insertion point of hostiles. He almost pulled up short at that last thought. It had been easy enough to submerge himself in the immediacy of his previous engagements, but this operation was very different.
	‘Something the matter, captain?’ asked Barkha. ‘We need to keep moving. We’ve caught them by surprise, but that won’t last.’
	‘I’m fine,’ Remus assured him, taking a last look at the bodies and shaking his head. The unthinkable had become a very real threat, and it was beholden to him to keep what was at stake in mind at all times. The nature of the opponent didn’t matter. All that mattered was the outcome. The Ultramarines had to fight, and they had to win.
	The stakes had never been higher.
	Victory ensured the survival of the most precious thing in the galaxy.
	Defeat would see it snuffed out forever, never to be seen again.
	Remus shook off thoughts that had no bearing on this fight. He was a captain of the Ultramarines and had a job to do. The enemy command post was located in this structure, and taking it out was key to the primarch’s overall strategy. Weeks of probing, cipher-breaking and after-action interpretation had allowed Ultramarines strategic planners to plot the most probable deployments of the enemy command and control elements. With the war for Quintarn still hanging in the balance, the time to make use of that predictive intelligence had arrived.
	As armoured elements engaged the leading edge of the dug-in defenders, Remus led his thirty warriors in a precise strike to decapitate the enemy command structure. Intercepted code transmissions indicated that the senior enemy commander was in theatre and this was too good an opportunity to pass up.
	Remus knew the layout of this structure intimately, and led his warriors towards the armoured blockhouse that contained the stairwell to the upper cloister. He kept low and hugged the parapet, his bolter aimed at the door. It didn’t make sense for the enemy to venture out, but these weren’t Ultramarines. Who could say how recklessly they would behave?
	He paused by a series of raised compression pipes, the metal hot to the touch and dripping with condensate. His warriors were moving into position, ready to assault the blockhouse, and he took a moment to glance over the angled parapet at the roof’s edge.
	The city stretched out around him, its metal-skinned towers and gleaming silos shining like silver beneath the beating sun. The Ultramarines quickly formed a perimeter as the gunship lifted off in a howl of engines that sounded like its namesake, and Remus watched as it peeled away, moving into formation with two-dozen others. Rippling beams of light lashed up from the ground towards the aircraft. Concealed batteries flayed the sky and half a dozen Thunderhawks were struck, each one falling out of formation and describing sinuous arcs towards the ground.
	Remus didn’t watch them fall, but pressed on towards the blockhouse mounted in the centre of the roof. Its door was armoured and no doubt sealed, but it would present no challenge to his assault team. No orders needed to be given. He had briefed his warriors prior to dust-off, and each man was aware of his role. Not only that, but following the prescriptions of the primarch’s great work, each man knew the role of every one of his brothers. Should any man fall, another of his brothers could take up his responsibilities.
	He moved forwards at speed, his bolter pulled tight into his shoulder. He could hear the sounds of fighting coming from other buildings: the sharp bangs of bolters and the whoosh-roar of enemy flame units. Remus felt his lip curl in a sneer. Such weapons might scare xenos forces, but held little fear for warriors armoured in the finest battle-plate forged by the weapon-masters of Macragge.
	Sergeant Archo and Brother Pilera ran to the armoured door. With practiced swiftness they rigged the hinges and lock with krak charges. Det-cord unspooled from their gauntlets as they took position to either side. At a nod from Remus, a silent data-squirt blew the charges and the door bulged inwards, as though struck by an invisible fist of colossal dimensions. Remus and Barkha ran forwards and thundered their boots against the door. The metal buckled, folded nearly in two by the awesome force.
	The twisted door toppled inwards, and before it had landed, another two Ultramarines hurled a handful of grenades through the smoking hole. Rippling detonations, curiously muted, like a string of firecrackers, echoed up from below. Barkha stepped towards the ruined frame, but Remus held up a fist, holding his warriors in place.
	A liquid jet of flame roiled up from within the blockhouse, bellowing with seething power as it licked up the stairs beyond the door. The blaze erupted from the door, but before the weapon could fire again, Remus nodded to Barkha. His sergeant swung around the door and loosed a barrage of bolter fire on full auto down the stairs. The noise was deafening, the booming reports echoing madly around the interior of the stairwell and lighting it with strobing flashes.
	Barkha pounded down the stairs and his squad followed him down. Remus led the second squad down, as Sergeant Archo formed his warriors behind him. The interior of the stairwell was blackened and scorched, like the flue of a volcano.
	Should make the bastards feel right at home, thought Remus.
	He emerged from the stairs into a wide cloister that ran around the inner faces of the structure. The building itself was a hollow rectangle with an interior courtyard, fifty metres wide and a hundred long. Gunfire snapped and banged from below, the enemy desperately trying to reorganise and realign their defences. Remus saw three command tanks – two Rhinos and a Land Raider – each with a forest of whip antenna bristling on its topside. The armoured vehicles were painted a drab green with black draconic heads embossed on their side doors.
	‘Archo, sweep left, Barkha, go right!’ he shouted.
	The words were unnecessary; both men knew exactly what to do. They had read the primarch’s treatise on such storming actions, and needed no input from him. Green-armoured warriors emerged from chambers further along the cloister, guns levelled, but they were already too late.
	The Ultramarines filled the space with shots, putting down such a weight of fire that even artificer-crafted battle-plate couldn’t withstand it for long. Remus fired his bolter on the move, compensating for the additional weight on the underside of his barrel. He automatically braced his shoulders for recoil, before remembering there was no need. The two warriors before him fell back, one toppling over the balustrade into the courtyard below, the other dropping with altogether less theatrics.
	Remus knelt beside the body, studying the armour and its iconography. Jagged-toothed dragons emblazoned upon fields of fire combined with hammer and forge symbols to create an earthy, Promethean feel. Too feral, too cultish to be Imperial. It had the look of a savage culture raised up to civilisation, but which would never really be civilised.
	Salamanders. Even the name sounded barbarous. A Legion named for the legendary fire-breathing monsters of a forgotten age. The name had no gravitas, and Remus shook his head at its primitive, visceral nature.
	‘How does it feel to die knowing you are my enemy?’ Remus asked the fallen Salamander.
	‘No different than when I died as your brother,’ said the warrior, before his head rolled to the side.
	Remus nodded, and paid the warrior no more attention.
	His visor changed to display the tactical situation. His warriors had swept through the upper reaches of the building, and were fighting their way to the lower level. The suddenness of their assault had caught the Salamanders off-guard, but there was still some fight left in these fire-loving cultists. Remus matched the ongoing status of the fight into his perfect recall of the primarch’s works, and immediately saw how they were going to break the defences open.
	‘Sergeants,’ said Remus. ‘The north stair is ready to fall. Archo, I want your squad on the south cloister. Lay down suppressing fire on those tanks and the warriors in the courtyard. Barkha, you and I will break in through the north while Archo keeps their heads down.’
	‘Understood,’ said Sergeant Archo. ‘Moving into position now.’
	Remus led his men around the cloister. Flames jetted up from below, and here and there grenades clattered as they looped over the parapet. Ultramarines hurled them back, but the Salamanders soon learned to hang on to their explosives before hurling them. Remus kept his head down as a cluster of grenades burst against a wall further along from him. Two of his warriors went down, their armour shrieking as they fell. He felt the enormous pressure wave roll over him, but it wasn’t enough to put him out of the fight.
	‘On!’ he cried. ‘Up and forward!’
	The Ultramarines rose and bolted for the stairs. Remus saw Barkha’s men opposite, and rolled around the corner to see the forward elements of his squad pouring fire down the stairwell. Barkha rounded the corner of the opposite cloister at the same time, and both men took up position at the top of the stairs.
	‘Resistance?’ asked Remus.
	‘Minimal, easily dealt with,’ was the terse reply.
	‘Assault in, three, two one…’
	Almost exactly on cue, a volley of heavy gunfire erupted on the far cloister. The chugging bark of heavy bolters filled the courtyard, followed straight after by the swooshing hiss of missiles. The fire up the stairwell slackened almost immediately. Remus spun around the corner and took the stairs down to the courtyard two at a time. A Salamander appeared at the opening below, the archway sparking with coruscating residue of the specially modified missile warheads. He levelled a meltagun at Remus, but a shot from Barkha took him in the head and punched him out of sight. Another Salamander fired his weapon around the archway without exposing himself, but the shots were wild. Remus’s armour registered an impact on his right shoulder, but the strike was glancing, and wasn’t nearly powerful enough to stop his charge.
	Remus burst into the courtyard, firing precise bursts of bolter fire at exposed enemy warriors. Hunched behind their vehicles to shelter from Archo’s fire from above, they were dangerously exposed from the rear, and three bursts of fire put down two of his opponents. The third Salamander took the hit, but didn’t fall. He raised his weapon, a pitch-blackened multi-melta. Remus pulled the trigger, and the hammer of his bolter fell on an empty chamber.
	He cursed his lax fire discipline and ran for the cover of an out-of-action Rhino.
	Before the multi-melta could fire, a missile struck the ground beside the gunner and the concussive force of the blast knocked the warrior from his feet. Remus slammed into cover, grateful that at least one of Archo’s gunners had thought to keep a shot back for an act of 4th Company recklessness. He grinned. Not even a primarch’s tome could completely erase the spirit of the Troublesome Fourth.
	Remus slotted home another magazine and scanned the killing ground of the courtyard, looking for rank badges or some other form of officer markings. He saw etchings of teeth, dragon amulets and various forge symbols, but nothing that resembled a logical progression of rank. He’d been briefed on the Salamander’s system of rank markings, but could see nothing that indicated any high level of commander lay among the dead.
	Had their intelligence been flawed?
	The thought was discarded immediately. The idea that Roboute Guilliman could be wrong about anything was beyond ridiculous. It was heretical, which, given this current engagement, was a rich irony indeed. He returned his attention to the battlefield, anxious that this mission be successful. So far the 4th Company had the foremost record of all the Legion’s battle companies, and he wasn’t about to blot their copybook with failure now.
	The two Salamanders Rhinos were registering as out of action, their command and control facilities destroyed beyond repair, yet the mighty, cliff-sided Land Raider was merely crippled. Its weapons were disabled, and one of its track units had suffered a debilitating impact. It wasn’t going anywhere in a hurry, but whoever was inside it was likely still alive.
	As if to confirm that fact, the Land Raider spun on its axis, its one functioning track grinding the flagstones to powder beneath the vehicle’s monstrous weight. The frontal assault ramp dropped and three figures emerged, titans amongst mortals, giants to their mere men.
	Terminators.
	Remus had seen Terminator armour during the battle for Calth, mighty suits of armour so colossal it seemed impossible that men could wear them. Such was the newness and complexity of the suits that only a handful of the Ultramarines 1st Company had been trained in their use. Nor were there nearly enough to outfit more than a few hundred of the 1st, for the initial Mechanicum mass conveyers had only just arrived at Macragge when news of the massacre at Isstvan V had arrived.
	Hulking, armour-plated behemoths, each Terminator was a full head and shoulders taller than the Ultramarines, the thick plates of their armour shrugging off bolter fire like light rain. Remus had seen the effect these warriors had had on the Word Bearers, but to face one was a new experience, and not one he was keen to repeat.
	One warrior bore a cloak of olive green mail over his left pauldron, and the vast skull of some unknown beast with elongated frontal fangs was affixed to his helmet, giving him the hideous appearance of some strange xenos barbarian warrior. In one hand, this warrior carried an enormous, oversized hammer wreathed with crackling energies, in the other a shield worked in the form of the honour badge that granted him the right to wear such terrifyingly powerful armour.
	Two others warriors accompanied this brutish war leader – surely the commander of this force of Salamanders – each a humanoid fighting tank armed with a monstrously oversized fist and a bulky weapon resembling two bolters welded together.
	Their bolters opened up with a ripping storm of fire, raking the courtyard from left to right in controlled bursts. Three Ultramarines went down, bracketed and gunned down by the commander’s two praetorians in concert. This was no random spray of fire, but a methodical slaughter. Shots flashed past Remus, but he ducked back into the cover of the Rhino as the streaking fire turned in his direction.
	The enemy commander didn’t come at them, instead turning his vast hammer on the walls of the courtyard in the lee of the Land Raider. One swing of the hammer put a man-sized hole in the wall. Masonry and steel reinforcement bars were smashed aside by the lethal weapon. Two more blows at most would see the enemy commander break free of their surprise assault. It would be next to impossible to mount an effective pursuit through the streets of Idrisia. Remus’s armour was already registering the flurry of vox traffic coming from the enemy commander as he summoned reinforcements. Within moments, the target would be lost.
	‘All forces, converge and close the net,’ he ordered. ‘Command target is on the move.’
	Ultramarines warriors broke cover, moving in stepped overwatch patterns, but where any normal enemy would be forced to keep their heads down under such a fusillade, the Terminators walked tall through enough firepower to reduce entire squads to shredded meat.
	Remus saw Barkha hit, his armour struck by multiple impacts from the oversized bolters. Barkha cursed and loosed a string of Talassarian vulgarities before dropping to the ground and lying still. Pinned down and with a rapidly diminishing roster of warriors, Remus knew he had only one chance to win this fight. The tactical situation had only one option left, and he opened a channel to Sergeant Archo.
	‘Archo, suppressive fire on the courtyard. Now!’
	‘Captain, that places you in the kill zone.’
	‘I know, just do it! Fill this place with fire!’
	The order didn’t need to be repeated. Archo knew his place in the chain of command. As did Remus. The mission was paramount. The primarch’s writings made it clear that the lives of friendly combatants were of paramount importance, especially Legiones Astartes lives, for they were sure to be in short supply in the coming years of war.
	But just as clearly, the primarch knew that wars were won by the blood of the soldiers fighting them. Sometimes the only way to win was to sacrifice everything for the victory.
	‘Hurry, Archo!’ he shouted as the enemy commander finally tore down the wall between him and escape.
	The courtyard erupted in fire and flame as missile after missile tore down into the courtyard. Heavy bolters raked back and forth, their fire brutally effective and lethally indiscriminate. A missile took the Salamander captain on the shoulder and the impact spun him around as another struck him full in the plastron. The force of the warheads drove him to his knees. Another missile streaked downwards, but the Salamander warrior brought his shield up to block it. The deflected missile corkscrewed into the courtyard, where it exploded in the midst of a knot of Ultramarines hunkering down behind what little cover remained.
	An unending storm of gunfire filled the courtyard, and Remus lost track of everything as the deafening cacophony of sound rolled through him. He’d lost control of this battle, but he could regain it if he could only see what had become of the Salamander war leader.
	He belly-crawled around the Rhino, his bolter crossed on his forearms as he skidded through the debris of battle. Shell casings, crushed masonry and bodies. The vox crackled and barked in his ear: nearby squads requesting updates, intercepted chatter from enemy units en route to the building, Thunderhawk pilots yelling warnings at one another. Remus blotted it all out, concentrating on moving at speed to fulfil his objective.
	Remus reached the end of the Rhino and scrambled to his knees. He had no chance to weigh his options or consult his primarch’s words, and simply swung around the corner of the vehicle’s track units. The Salamander Terminator had found his feet, though Remus’s visor displayed numerous weakened points on his armour.
	The Salamander war leader, perhaps sensing his presence, turned to face him. Remus met his gaze, eye lens to eye lens. Remus sighted along the length of his bolter, and though he couldn’t see beyond the snarling ceramite war mask, he felt he could see the warrior’s coal dark skin and infernal red eyes. Of course that was ridiculous, but there was a weak spot on the warrior’s faceplate, one that a skilled marksman could exploit…
	Remus squeezed the trigger and the bolter spat a single shot. Though the weapon fired at supersonic speed, Remus felt he could trace its passage through the air. Even as fired, he knew the shot was true. It struck the Salamander square in the face and Remus watched as his visor registered the kill. The Terminator didn’t fall; the armour was too massive to let the wearer collapse, even in death.
	Remus let out a breath, rolling onto his back and letting the exertions of this latest engagement drain from him. Though it had been among the shortest, it had been one of the most demanding.
	High above the building, roaring Thunderhawks descended like carrion birds circling in anticipation of a feast.
	Engagement 314
	A cold wind blew down the basalt canyon, carrying dust from the high peaks of Macragge. Remus smelled the pinesap of highland evergreens and the crystalline sharpness of mountaintop tarns on the breeze. He crouched low behind a marker cairn, a three-metre cone of stacked volcanic rock with ancient markings that directed travellers to safe paths through the mountains, locations of water and shelter. Cut in the ancient cuneiform of Macragge, these markings would be unreadable to anyone not native to this world, meaningless even to another citizen of Ultramar.
	It had been many years since Remus had run through these mountains as a boy, staggering in an exhausted, near-death state from one cairn to another as he fought for his place in the Ultramarines. Of all the boys that had set off on that last run, he alone had survived; the others dying one by one of heat exhaustion, dehydration, or falls from high cliffs, or being picked off by the vicious, cave-dwelling mountain cats that stalked the high peaks.
	Tumbling through the bronze gates of the Fortress of Hera, Remus had been met by Captain Pendarron, the heroic warrior who had fought alongside Roboute Guilliman in the untamed lands of Illyrium before Gallan’s betrayal of the Battle King Konor. The captain had picked him up, dusted him down, and sent him to the apothecarion with a curt nod of approbation.
	Thinking back to that time brought a welcome flush of endorphins, but it was a short-lived pleasure. That was another life ago, and nearly two centuries of war separated that young boy from the Legiones Astartes Remus had become. Decades of training still awaited that young boy, but they had been years of intense pressure, tribulation and, yes, joy. Proving himself worthy of a place within the ranks of the Ultramarines had been his greatest honour, and he still recalled his mother’s pride at seeing him march through the streets of Macragge clad in brilliant blue battle-plate.
	He had never seen his mother again, yet the loss did not touch him as deeply as he felt it should. His mind had been reshaped in myriad ways, and though the capacity for sadness and emotion had not been removed, it took extreme stimuli to trigger emotions connected with his previous life as a mortal.
	A crackle on the vox-network brought Remus out of his reverie, and he shook off thoughts of golden days and concentrated on the present dark ones. This campaign had been the toughest of all, for the Sons of Horus had consistently outfought and outmanoeuvred them at every turn. In space, the Warmaster’s fleets had battered through their picket lines, and flanking forces of stealthy ambush vessels had appeared from nowhere to wreak havoc within the Ultramarines precise battle lines.
	World after world had fallen. Tarentus, Masali and Quintarn were gone, the loss of the latter planet bringing a lump of bile to Remus’s throat after all the 4th Company had gone through in their struggle against the Salamanders. Prandium was now lost, the devastation begun by the World Eaters now concluded by a viral bombardment that stripped the ruined planet of all living matter in a viral hellstorm. All that was left of Prandium was a barren rock.
	Iax had been firebombed until the Garden of Ultramar was an ashen wasteland. No two campaigns the Warmaster waged were fought the same way, and Remus had heard whispers in the higher echelons of command that the planners in the grand strategium were running out of ideas to fight him. Remus knew that could not be true. The primarch’s writings would have a solution to this assault on Ultramar, it was just too complex and overarching a plan to be comprehended by mortals, even ones as cognitively enhanced as the Legiones Astartes.
	Roboute Guilliman had never yet lost a war, and he certainly wouldn’t lose this one.
	Macragge could not fall.
	It just couldn’t.
	Remus didn’t know whether to think of that as fact or wishful thinking.
	Barkha scrambled over the rocky ground towards him, keeping low behind the fangs of rock that sheltered this element of the 4th Company. Thirty metres below, the floor of the canyon twisted a serpentine path through the mountains, the ground flat and hard-packed. Well away from the battles being fought in the lowland approaches to the Fortress of Hera, it had been decided that it was certain the Warmaster would move flanking forces through these canyons to open a second front against the Ultramarines last bastion.
	The 4th Company guarded the passes to ensure no second front was opened.
	‘They’re coming,’ said Barkha. ‘Sons of Horus armour units, with speeders and bikes in the vanguard. It’s a pretty small force, but there’s bound to be others threading their way over the mountains.’
	That was true enough, but numerous elements of the 4th Company were watching the secret paths through the mountains. 
	‘What’s their separation like?’
	‘Sloppy,’ said Barkha. ‘They’re in a hurry. The tanks are labouring, and the bikes are slowing down to keep close.’
	Remus looked down into the canyon, hearing the distant rumbling of the enemy vehicles as they approached the killing box. The mountains of Macragge were a different order of inimical environment to any the Sons of Horus would have encountered before. Time and time again, the enemies of Macragge had been undone by its hostile geography. The Sons of Horus would be no different.
	‘Pass the word. Fire on my signal. Target the lead tank and the rear tank. Trap them in the box and then work your way to the centre.’
	‘Understood,’ said Barkha, and Remus heard the note of exasperation in the sergeant’s voice. The 4th Company had practised drills like these countless times, and didn’t need him to tell them how to run an ambush. Remus checked his bolter one last time and propped himself against a rock with a view through a knife-cut in the rocks before him. He could see down into the canyon, but the shadows and dark hue of the rock concealed him from view.
	He overlaid a tactical schematic over the view of the canyon, seeing his warriors picked out in pale blue throughout the overlooking crags and gullies. There wasn’t an angle left uncovered, an escape route that wasn’t a death trap or a square centimetre of ground that couldn’t be reached by Ultramarines gunfire.
	‘Easy meat,’ whispered Remus.
	The noise of engines grew louder, echoing from the canyon walls. Remus heard the chugging breath of Rhinos, the deeper, throaty rumble of Predators and the roaring thunder of at least one Land Raider. The high-pitched bleat of bikes carried over the noise, and Remus kept his head down as a pair of speeders zipped into view.
	Both were painted in the sea green of the Sons of Horus, their frontal glacis emblazoned with a flame-coloured eye. The speeders paused, like sniffer dogs hunting a scent, but Remus knew these mountains well and had placed his kill teams with perfect cover. No matter how sophisticated the speeders’ surveyor packages were, they wouldn’t find his warriors.
	The speeders carefully eased their way into the canyon, swiftly followed by a five-strong squad of bikes, each one heavily armoured and fitted with forward-firing bolters. A black banner decorated with yet another eye symbol flapped behind the lead bike, and Remus fought the urge to open fire on these invaders.
	Then the tanks came, a pair of Rhinos, swiftly followed by three Predators and the grumbling monster of a Land Raider. Another three Rhinos followed it, and yet another pair of Predators formed a rearguard. Barkha had called this a small force, and measured against the scale of warfare a Legion could put in the field it was, but this was still a formidable display of firepower.
	The bikes and speeders moved off, and Remus knew they were never going to get a better chance than this. He pushed onto his knees and sighted down his bolter at the pilot of the nearest speeder. He squeezed off a round, and was rewarded by a kill signal in his helmet. The vehicle slewed away as the pilot slumped over his controls. Remus’s shot was the signal to his ambush force, but before a single shot could be fired, a booming volley of gunfire sounded from higher in the mountains.
	Remus saw his men die in droves from the deadly accurate fire, and spun to see dozens of muzzle flashes from the rocks higher in the mountains. Ultramarines icons were winking out on his visor, and his moment of paralysed shock almost cost him his life. His armour registered two impacts, both glancing and not serious enough to hamper him, but he dived into the cover of the stacked cairn.
	‘Barkha!’ he yelled, returning fire uphill. ‘Do you have a visual?’
	‘Affirmative,’ came the sergeant’s harried voice over the vox. ‘Sons of Horus infiltrators. Squad markings match those on the vehicles below.’
	Remus was stunned at this turn of events. How could the Sons of Horus have gotten behind them? How had they known the Ultramarines were lying in wait for them? 
	Furious exchanges of gunfire flickered back and forth between the two forces, and Remus knew the vehicles below would soon be adding their own weight of fire to the fight. The ambushers had been ambushed, and there was no sense in continuing an engagement that was already lost. The primarch’s words on the subject were abundantly clear.
	When they have the drop on you, don’t draw.
	‘All units,’ ordered Remus. ‘Withdraw and regroup. Rally point Ultima Sextus. Go!’
	Remus bounded from cover to cover, firing as he went. He had no time to aim, and just had to hope that his wild shots hit one of these Sons of Horus bastards. He heard the bark of gunfire all around him, punctuated by the roar of vehicle engines and the crash of artillery pieces launching arcing volleys of shells. A ragged group of Ultramarines ran with him, an amalgamation of three squads he’d gathered after the rout from Konor’s Gate further down the mountains.
	Every move they’d made, the Sons of Horus had countered or circumvented. It had been humiliating to find that every recourse to his primarch’s words had resulted in dismal failure. Remus despaired of winning this fight, but had to keep faith that some grander stratagem was yet to reveal itself.
	Bolts of light streaked overhead, withering storms of las-fire as helots traded fire with forward units of the Warmaster’s army. Remus had no tactical view; a shot from a Sons of Horus sniper had damaged his helmet beyond repair and so he had discarded it three kilometres back. To fight with his head unprotected was an alien sensation to Remus, denying him access to all manner of battlefield information, but the connection to the visceral nature of the fighting couldn’t be denied. To smell the acrid reek of propellant fuel, the backwash of shellfire and the burnt air taste of las-fire was a powerful kick in the guts to keep your head down.
	Sweat streaked his face and black dust covered his scalp. Above him, the sky was a swirl of colourful streaks of gunfire and arcing explosions. The noise was unlike anything he had experienced before, a mix of snapping small-arms fire, mixed with the deeper bangs of close-firing heavy guns.
	Sergeant Archo crouched in a makeshift trench; his warriors taking cover beneath its firing step as the Sons of Horus advanced behind a creeping barrage of artillery. Just like in the canyons to the south, the Warmaster’s forces had consistently blindsided the Ultramarines, which seemed so absurdly improbable, that Remus wondered if this was not some hideous nightmare from which he could not awaken.
	He risked a glance over the rocks, seeing a grimly advancing wave of warriors armoured in the colours of the Sons of Horus. Each bore the eye of Horus device upon their chest, and that same symbol was repeated on the banners flapping from the aerials of the hundreds of armoured vehicles pouring fire uphill.
	‘Not so fancy now, are they?’ said Barkha, dropping in beside Remus. Like the captain of the 4th Company, Barkha had removed his helmet, his leathery skin tanned almost black and his hair bound in tight cornrows to a short ponytail at the nape of his neck.
	‘They don’t need to be,’ replied Remus.
	‘What do you mean?’
	‘Exactly what I said. We’re all out of options. The Warmaster has a knife to our throat, and he has no more need for subtlety. This is the death blow.’
	‘Truly?’ said Barkha, and Remus saw the fear of that fact written all across his face. ‘We must have some plan to meet this attack?’
	‘Then tell me what else we can do? Every stratagem has been met and countered. Every subterfuge of war has been anticipated and defeated. All we can do now is fight like true warrior kings of Ultramar and take as many of the bastards with us as we can.’
	‘But the primarch must have considered this situation,’ pressed Barkha. ‘You must have misread his words or issued a wrong order. That’s the only way we could have been brought to this.’
	Remus shook his head. ‘You think I haven’t thought that since this engagement began? I’ve been over it all a hundred times, and I forgot nothing, misread nothing. We did everything that could have been done.’
	‘Then how has it come to this?’
	‘Because there are some things that can’t be met with plans and preparation,’ said Remus. ‘Some warriors are clever enough to ram a speartip through the spokes of any plan, no matter how brilliantly conceived. The Warmaster is such a warrior.’
	‘But Primarch Guilliman…’
	‘Does not fight with us,’ snapped Remus. ‘Now stop talking and start killing!’
	Step by brutal step, the Ultramarines were pushed back up the mountains, leaving thousands of fallen warriors in their wake. Every metre gained by the Sons of Horus was paid for in lives, but Remus had been right; this was the death blow. 
	With the Fortress of Hera at their backs, the defenders of Macragge prepared for their last battle. To yield the land of their forefathers without a fight was not the Ultramarines way, but the time was almost at hand where they would need to face the Warmaster from behind marble parapets and towers of gold and silver. If this was the end then it would be the most glorious end imaginable.
	Remus had volunteered the 4th Company to act as the Ultramarines rearguard, and they took position on the Via Fortissimus, the great road that led from the plains below to the mighty bronze gate of their Legion fortress. Behind them, the depleted ranks of the Ultramarines battle companies that still survived all but fled to the transient safety of the Fortress of Hera.
	If the Warmaster’s armies had made one thing clear, it was that nowhere was truly safe.
	On Macragge or anywhere in the galaxy.
	As the Sons of Horus prepared for their final push towards the gates, Remus saw a colossal Land Raider rumble through the ranks of the enemy. Though no larger than any other such armoured vehicle, a trick of the moment seemed to render it mightier than any vehicle had a right to be. Bellicose cheers greeted this tank, and as its assault ramp lowered to the volcanic rock of the mountains, Remus saw why its arrival warranted such an outpouring of devotion.
	The warrior who stepped from its red-lit interior was of such magnitude that it seemed he dwarfed all those around him. His armour was of deepest black, gleaming and pristine with gold chains and a fur-lined cape of foxbat hide. A helmet of such perfect symmetry that it made Remus want to weep concealed the warrior’s face, and though he knew whose face lay behind the visor, he dreaded seeing it lifted.
	Remus felt the breath catch in his throat.
	The Warmaster.Horus Lupercal…
	The Emperor’s brightest, bastard son had come to witness the final humiliation of the Ultramarines.
	The Sons of Horus cheered, the sound echoing from the mountains like the battle cry of some ancient, heathen tribe. Their war shouts were imprecations to forgotten, bloody gods, and every man of the 4th Company felt a tremor of fear worm its way into his heart at the sight of this avatar of blood and death.
	What could stand against such a foe and live?
	What army could withstand the genius of this warrior’s intellect?
	We may not defeat him, but that we stand against him will be remembered, thought Remus. Perhaps that is enough…
	‘Warriors of Ultramar!’ bellowed Remus. ‘Remember where you are and in whose name you fight. Each and every one of you is a hero of the Ultramarines, a warrior without compare, and a killer whose heart is unbroken!’
	Remus felt his conviction and choler grow with every word, his voice carrying easily over the mountains to the Ultramarines warriors withdrawing to the fortress and the assembling Sons of Horus. ‘Only in death does our duty to the Emperor’s dream end, and only with our death will it die. I will not let that dream die, will you?’
	As one, the 4th company answered with a resounding, ‘No!’ and their denial echoed strangely from the mountainsides such that it sounded as though some among the Sons of Horus joined in.
	The mighty warrior in the centre of the enemy ranks raised his fist. Sunlight caught the gold edging of his gauntlet as four gleaming blades slid from its upper faces. The gauntlet swept down and the Sons of Horus charged.
	The battle was without finesse, without glory and without hope of success for the XIII Legion. Though Remus had followed every tenet contained within the primarch’s writings, everything came down to this last desperate fight. It was an artillery bombardment, a long range duel, a short range firefight and, at the last, a close-up storm of blades and fists.
	Remus had long since expended his cache of ammo, and switched to his blade. His every blow was struck with desperate fervour, his every parry made with a frantic desire to stay alive and to kill as many of these invaders as possible. Any semblance of shape to the battle had been lost the instant the two forces collided.
	Warriors in brilliant blue swirled in an ever-shifting melee of hacking blades with traitors in the green of a distant ocean. Even as he fought, Remus wondered how history would remember this war. Who would be recalled as the traitors? Future history was the provision of the victors, so who could say in what role the Ultramarines would be cast? Would-be saviours of a glorious ideal that died in the mountains of Macragge, or base traitors whose arrogance was matched only by the scale of their failure?
	They fought in an ever-decreasing circle of warriors, Ultramarines falling with every passing moment as the enemy overwhelmed them. Like a noose tightening on the throat of a condemned man, the life was choked from the 4th Company’s defiance until only Remus remained.
	He had given his all, but it had not been enough. The strength that had fuelled him during these engagements fled his body. He had been struck so many times that it was a wonder he was still standing. Remus slumped to his knees, broken by disappointment and robbed of his certainty by this defeat. His head bowed as he imagined the scale of his failure.
	Remus looked up as an enormous shadow enveloped him.
	The Warmaster towered over Remus, his vast gauntlet raised high like the talons of some lethal predator. Remus awaited the blow that would end this farce, but instead of death, the Warmaster’s claws retracted into the gauntlet. Horus Lupercal raised his hands to his helmet, unsnapping the gorget seals that secured it in place.
	Remus couldn’t bear to look at him.
	‘Look at me,’ said a voice golden with perfection.
	‘I can’t,’ said Remus. ‘I failed.’
	‘No, Remus Ventanus,’ said Roboute Guilliman. ‘You didn’t. The failure was mine.’
	Remus sat alone on the spur of a rocky cliff overlooking the Fortress of Hera. It seemed absurd for it to look so quiet, when only hours before it had been the scene of so terrible a conflict. Helots and Legion serfs scoured the mountainside of debris, shell-casings and dented pieces of armour torn from the combatants. 
	The Legion armourers were already repainting the suits of battle-plate and vehicles that had masqueraded upon the field of battle in the Sons of Horus livery. The halls of the Legion stank of thinner and paint as ‘enemy’ colours and markings were once again removed from armoured plates and weaponry.
	Remus had deposited his battle-plate in his arming chamber and instructed his new equerry to have it cleaned and serviced, a task he would normally attend to himself, but which felt somehow wrong today. He had torn the laser designator from the barrel of his weapon and hurled it from the cliffs, despising what it represented and hating that such a device had even been necessary.
	Dressed in tan fatigues and a simple chiton of pale blue, Remus let the sun warm his face and awaited the reprimands that would undoubtedly follow his and the Legion’s failure to resist the attack of the Sons of Horus.
	Was there anything he could have done?
	Could any warrior have bested the Sons of Horus?
	A sudden smile crept across his face as Remus realised there was one warrior who might have turned the tide of battle…
	‘There was nothing you could have done,’ said a voice behind him, and Remus turned to see Roboute Guilliman. He rose to his feet, bowing his head in contrition to his gene-sire. One could not look too long at the sun without being blinded by its radiance, and the same was true of Roboute Guilliman. Sculpted to perfection, his classical features were tanned and smooth, gracefully formed and handsomely arranged like the statues lining the Via Triumphal that led to the Sanctuary of Correction at the heart of the Fortress of Hera.
	Guilliman walked to the edge of the cliff, staring out over his domain, and Remus took his position at the primarch’s shoulder, though the top of his head reached only to the middle of his liege-lord’s bicep. Like Remus, Guilliman was stripped out of his armour and wore light training robes, though Remus could not shake the image of the primarch clad in the midnight-black plate of the Warmaster. Though patches of its cerulean brilliance had shone through like sunlight on a cloudy day, the image of so fine a figure as the Ultramarines primarch clad as a traitor would never leave him.
	‘I must have done something wrong,’ said Remus. ‘It is the only explanation.’
	Guilliman shook his head and smiled grimly. ‘You credit me with too much, Remus. I am not infallible. This last engagement should have shown you that.’
	‘I can’t accept that,’ said Remus.
	‘What is so hard to accept?’ said Guilliman. ‘You followed my teachings, and they led you to defeat. If this and Calth have taught us anything it is that we must always be adaptable and never too hidebound in our thinking.’
	‘But your teachings…’
	‘Are yet flawed,’ said Guilliman. ‘No one, not even one such as I, can anticipate every possible outcome of battle. My words are not some holy writ that must be obeyed. There must always be room for personal initiative on the battlefield. You and I both know how one spark of heroism can turn the tide of battle. That knowledge and personal experience can only be earned in blood, and the leader in the field must always be the ultimate arbiter of what course of action should be followed.’
	‘I’ll remind you of that when the Troublesome Fourth are next in the field.’
	Guilliman chuckled. ‘Be sure that you do, Remus. I am aware that some think me emotionless, the Talos of ancient days come to life, and desiring only to suffocate free thinking with my prescriptive ways. But such times are upon us that brook no deviation from our course.’
	‘So was there a way to win that last fight?’
	‘Perhaps, but I will let you find that answer.’
	‘And what will you do?’
	‘I will continue to pen the Codex Astartes,’ said Guilliman.
	‘Codex Astartes?’ said Remus. ‘Is that what you are calling it?’
	Guilliman smiled and nodded. ‘Yes, I think it has an appropriately weighty feel to it, don’t you? In war and in peace it will provide an invaluable repository of knowledge, but I do not wish it to be regarded as a substitute for reason and initiative. Do you understand?’
	‘I think so,’ said Remus, as Guilliman beckoned him over to the edge of the cliff.
	‘These are the darkest days the Imperium has known,’ said Guilliman. ‘And I fear for what the future will bring. Calth is lost to us, and Isstvan. Who knows how many other worlds my brother will burn in his madness?’
	‘But you have a plan to fight him?’ pleaded Remus.
	Guilliman did not answer, as though afraid of what Remus might make of his answer.
	At last he said, ‘I have a plan, yes, and it is a dangerous one, too dangerous to divulge for the moment. But when the time comes to put it into action, I must ask you all to trust me as never before. When that time comes, you will be called traitors, cowards and faithless weaklings, but nothing could be further from the truth. I can see no hope in the times ahead for the Imperium as we know it, and that is why I had you fight these mock engagements. However this war plays out, it is inevitable that you will need to fight warriors you count as brothers. Perhaps even those who currently stand in opposition to the Warmaster.’
	‘I won’t pretend to understand what that means, but you can count on us to do everything you ask of us,’ promised Remus.
	‘I know I can,’ said Guilliman.
	‘We beat every army you sent at us, but I have had time to think why we lost against the Sons of Horus.’
	‘That was quick.’
	‘I’m a fast learner.’
	‘True. So what is your conclusion?’ asked Guilliman.
	‘It wasn’t a fair contest of arms.’
	‘How so?’
	‘You didn’t fight alongside us,’ said Remus.
	‘And you believe that would have made a difference?’
	‘I know it would have made a difference,’ said Remus, looking up at Guilliman’s perfect features. ‘And you know it too.’
	Guilliman shrugged modestly, but Remus could see that the primarch agreed with him.
	Roboute Guilliman looked up into the heavens, as though trying to perceive some far distant truth or faraway battle yet to come. At last Guilliman turned to Remus, and the captain of the 4th Company saw a haunted look in his eyes, like a desire clung to in the face of hopelessness.
	‘Then let us hope that when the Warmaster is to be put down, I am the man facing him.’