'Vox transmission from Destroyer Squadron Twelve,' Captain Stenius reported, joining the primarch at the strategium's primary hololith display. 'Long-range surveyors are picking up thirty vessels anchored in high orbit above the forge world. Reactor and sensor emissions suggest a mixed group of capital ships and heavy-grade cargo transports.'
Lion El'Jonson rested his hands against the burnished metal rim of the tank. A faint smile played at the corners of his mouth. 'Identification?'
Stenius shook his head. He was another veteran of the Legion's earliest campaigns, and bore the scars of his service proudly. His eyes were silver-rimmed, smoke-grey lenses set deeply into sockets that were seamed with scars. Nerve damage, inflicted by razor-sharp slivers of glass from an exploding hololith display, had transformed his face into a grim, inscrutable mask.
'None of the vessels in orbit are flashing ident codes,' the captain replied. 'But Commander Bracchius, aboard Rapier, claims the reactor signatures from two of the larger craft match those of the grand cruisers Forinax and Leonis.'
The primarch nodded. 'Formidable ships, but well past their prime. I expected as much: Horus has sent a second-line fleet comprised of renegade Imperial warships and Army units to plunder Diamat, while holding back his Astartes to protect Isstvan V.'
Stenius watched gravely as the hololith image above the table updated to reflect the new data. Diamat hung in the centre of the display, rendered in mottled shades of rust, ochre and burnt iron. Tiny red icons dotted the face of the world facing the approaching Dark Angels battle group, marking the approximate size and location of the enemy ships in orbit. Two of the icons had been tentatively classified as the two rebel grand cruisers, while others were given probable classifications based on their size and reactor emissions. Currently, the plot was showing no less than twenty cruiser-sized contacts anchored at Diamat, clustered around another ten heavy transports.
Nemiel, standing to Jonson's left on the other side of the hololith table, saw the concern in the captain's eyes. Second-rate or not, the rebels had twice as many capital ships as they did. For the moment, the Dark Angels enjoyed the advantage of surprise, and the enemy had been caught with little room to manoeuvre, but it was anyone's guess how long that would last.
Tension and uncertainty hung heavy in the dimly-lit chamber; Nemiel had observed it for weeks in the hunched shoulders and hushed exchanges between the fleet officers. During the two-month voyage from the Gordia system the news of Horus's betrayal and the nature of their clandestine mission had left indelible marks on the crew's psyche.
They've lost their faith, Nemiel thought. And why not? The unimaginable had occurred. Warmaster Horus, the Emperor's favoured son, has turned his back on the Emperor, and brother has been set against brother. He studied the faces of the men inside the strategium and saw the same fear lurking in the depths of their eyes. No one knows who to trust any more, he sensed. If someone like Horus could fall, who might be next?
The two hundred Astartes aboard the flagship dealt with their own uncertainties as they always did: honing their skills and preparing themselves mentally and physically for battle. Early in the voyage, Jonson had issued a set of directives organising his hand-picked squads into two small companies and establishing a rigorous training regimen to cement them into a cohesive fighting unit.
As the only Chaplain aboard the battle barge, Nemiel found himself personally tasked by Jonson to monitor the Astartes' training regimen and periodically certify their physical and psychological fitness. Since virtually all of the Legion's senior staff members had been left behind at Gordia IV, Nemiel soon found his responsibilities expanded to include logistics and fleet operations as well. He accepted the extra duties with pride and a certain amount of uneasiness as well, because the more he worked alongside Lion El'Jonson, the less sense the undertaking to Diamat made. Such a relatively small force couldn't possibly hold out for very long against the full strength of four rebel Legions, and Nemiel couldn't imagine that the Emperor would have ordered Jonson to attempt such a thing. The more he thought about it, the more certain he became that the primarch had ordered the expedition to Diamat for reasons that were entirely his own.
Nemiel focused his attention on the tactical plot and tried to put his foreboding aside. 'The rebels have us outnumbered, my lord,' he pointed out.
Jonson gave Nemiel a sidelong look. 'I can perform hyperspatial calculations in my head, brother,' he said wryly 'I think I can manage to count to thirty unaided.'
Nemiel shifted uncomfortably. 'Yes, of course, my lord,' he said quickly. 'I don't mean to belabour the obvious; I was just curious as to your strategy—'
'Easy, brother,' Jonson chuckled, clapping Nemiel on the shoulder. 'I know what you meant.' He pointed to the cluster of transports above Diamat. 'That's going to be their weak point,' he said. 'The success or failure of their mission depends on the survival of those big, lumbering ships, and they're going to hang like an anchor around the rebel admiral's neck.' He glanced back at Stenius. 'Any picket ships?'
Stenius nodded. 'Bracchius reports three squadrons of escorts in a staggered sentry formation,' he reported. 'They have detected our scouts and are coming about to engage. Time to contact is one hour, fifteen minutes at current course and speed.' He straightened, hands clasped behind his back. 'What are your orders, my lord?' he inquired formally.
The battle group had reached the point of no return. At this point, more than one and a half astronomical units from Diamat, the battle group still had time and manoeuvring room to come about and retreat from the system. If Jonson chose to press ahead, it would commit his small force irrevocably to battle.
Jonson did not hesitate. 'Execute attack plan Alpha,' he said calmly, 'and send the signal to launch all Stormbirds. Bracchius is to maintain speed and engage as soon as the pickets come within range. He'll have the honour of striking the first blow against Horus's rebels.'
Stenius bowed to the primarch and turned about, issuing a stream of orders to the flagship's command staff. Jonson turned his attention back to the tactical plot. 'Brother-Redemptor Nemiel, inform the company commanders to prepare their squads for an orbital assault,' he said. 'I expect we will be in position to launch in just over three hours' time.'
'At once, my lord,' Nemiel replied, and began to relay the command through his vox-bead. The image above the hololith tank updated again, this time depicting the approximate location of the battle group's three small scout squadrons. Ahead of them, three much larger squadrons were displayed in bright red, shifting slowly into a rough crescent formation. The arms of the crescent were oriented towards the oncoming Imperial scouts, like a pair of encircling arms. Blue and red numerical data, depicting the range, course and speed of the two formations changed with steadily-increasing speed.
Lion El'Jonson studied the glowing motes of data and folded his arms, his expression distant and thoughtful. Nemiel watched another ghostly smile play across the primarch's face as both forces arrayed themselves for battle, and fought down another twinge of unease. At that moment he would have given a great deal to know what Jonson saw in the grim picture that he did not.
As soon as the Dark Angels' battle group had arrived in the Gehinnon star system it had effectively split into two forces. Six of the group's sixteen ships were sleek, swift destroyers, which the primarch immediately ordered ahead of the main division with a trio of light cruisers to provide support. These scout squadrons quickly pulled ahead of the larger and slower cruisers, their long-range surveyors sweeping the void ahead of them and attempting to fix the size and disposition of the enemy fleet.
Now that the enemy was sighted, vox signals went back and forth between the two destroyer squadrons and the trio of light cruisers hanging back in their wake. As the rebel picket ships - no less than fifteen enemy destroyers, organised into three large squadrons - deployed into a standard crescent formation, Jonson's light cruisers flared their thrusters and moved up to form a battle line with the rest of the scouts.
Thousands of kilometres behind them, the main body of Jonson's battle group was altering formation as well. The Invincible Reason and the strike cruisers Amadis and Adzikel drew ahead of the two grand cruisers and two heavy cruisers that comprised the rest of the main force. At the same time, the armoured blast doors covering the three ships' prow hangar bays slid ponderously open and flight after flight of Stormbirds leapt like loosed arrows into the darkness. Within minutes, seven squadrons of the heavily-armed assault craft were speeding ahead of the formation, racing to join up with the distant scouts before the rebel destroyers reached extreme firing range.
With four minutes left to contact, the rebel pickets suddenly increased speed; perhaps the flotilla commander detected the oncoming Stormbirds, or gave in to his eagerness to open the engagement, but it was too little, too late. Jonson's Stormbirds were streaking through the scout squadron's firing line just as the enemy destroyers opened fire.
The rebel ships opened the engagement as Jonson expected they would, opening their bow tubes and launching a salvo of deadly torpedoes at the oncoming scouts. Thirty of the huge missiles - each one powerful enough to blow a destroyer-sized ship apart - sped towards the scouts in a wide arc that left the Imperial ships with no room to escape.
Surveyor arrays aboard the Stormbirds detected the launches at once, and the Astartes pilots spread out their formations as widely as possible to intercept the oncoming torpedoes. They swept through the volley of missiles in the space of a few seconds; lascannons spat bolts of searing light, spearing through the torpedoes' casings and detonating their huge fuel tanks. Massive explosions flickered angrily in the darkness in the Stormbirds' wake, spreading clouds of incandescent gas and debris that faded quickly in the airless void. Almost half of the torpedoes were destroyed; the rest sped onward towards their targets, too fast for the assault ships to alter course and come around for another pass. The Astartes held their course, already picking out targets among the oncoming picket ships.
The scout squadrons opened fire on the incoming missiles as soon as they came within range. Macro cannons and rapid-cycle megalasers filled the vacuum ahead of the small ships with a veritable wall of fire. Energy lances - massive beams of voltaic power - swept in burning arcs ahead of the light cruisers. More globes of flame bloomed along the path of the onrushing scouts, blending together into a seething field of vaporised metal and radioactive gas.
Five torpedoes slipped through the maelstrom. They crossed the remaining space to their targets in less than a second, flying into a second, smaller cloud of exploding shells as the destroyers' flak batteries opened fire. The servitor-crewed guns succeeded in destroying two of the remaining missiles.
Three torpedoes out of thirty struck home. One of the weapons smashed into the prow of the destroyer Audacious but failed to detonate; Hotspur and Stiletto, however, were not so fortunate. The torpedoes' plasma warheads tore the lightly-armoured destroyers apart, transforming them into expanding clouds of gas and debris in a single instant. Horus's rebels had claimed first blood.
The surviving ships passed through the remnant gases of the intercepted torpedoes, wreathing their void shields with streamers of plasma and temporarily fouling their auspex returns. Hungry for vengeance, their surveyor crews strained at their scopes, searching for engine telltales amid the storm of interference. Moments passed; points of heat swelled like stars in the radioactive haze. Ranges and vectors were calculated and relayed down to the torpedomen, who entered the data into their deadly charges. While the enemy pickets were still trying to reload their tubes, the scouts launched a torpedo salvo of their own.
By this time, the two formations were at extreme weapons' range, and the enemy pickets were faced with a dilemma: fire at the oncoming Stormbirds, the torpedo salvo or the scout squadrons behind them. The flotilla commander was forced to make a split-second decision, ordering all gun batteries to target the scouts and leaving the rest to the flak guns.
It was a brave but costly tactic. The Stormbirds reached the pickets first, each squadron orientating on a target and thundering in at full power. Explosive shells and multilaser bolts hammered at the oncoming assault craft, but the heavily-armoured Stormbirds pressed on through the barrage. Here and there an enemy shot struck home; engines exploded or cockpits were shattered by direct hits, but the rest continued their attack. They swept in low across the destroyers' upper decks, pummelling their hull and superstructure with cannon fire and melta rockets. Four of the pickets staggered out of formation, their bridges smashed and their decks ablaze.
Seconds later the Imperial torpedoes struck. Seven of them hit their targets, blowing the rebel destroyers apart. The four surviving ships plunged onwards, doggedly trading blow for blow with the scout squadrons. Their void shields blazed beneath a rain of explosive shells and ravening lance beams as they plunged into the Imperial formation. At such close range the gunners could scarcely miss their targets; one by one the shields of the rebel ships failed and the concentrated Imperial fire ripped them open from stem to stern.
But Horus's ships and their veteran crews died hard. They concentrated their fire on the survivors of Destroyer Squadron Twelve, pouring fire into Rapier and Courageous. The void shields of the two destroyers collapsed beneath the onslaught; Courageous died a moment later as a shell found its way into her main reactor room. Rapier fought on a few seconds more, destroying one of the picket ships with her last salvo, before an enemy shell detonated in her torpedo magazine.
Forty seconds had passed since the rebels' first salvo. Captain Ivers, master of the light cruiser Formidable, sent a terse vox to the flagship: the way to Diamat was clear.
'Increase speed,' Jonson ordered, watching the telltales update on the tactical plot. They were less than a quarter of a million kilometres from Diamat now, well within range of the battle group's surveyor arrays, and they were getting positional updates on the enemy fleet in real time.
It had been more than an hour since the initial engagement against the rebel pickets. The Stormbirds had been recovered and were being rearmed for another sortie. Nemiel had expected that the surviving escorts would be withdrawn as well, but Jonson had instead sent the depleted force on a roundabout course that threatened to swing around the far left flank of the enemy squadrons that had weighed anchor and were forming a battle line between Jonson's force and the planet. The rebel transports were still in high orbit above Diamat, surrounded by a protective cordon of eight cruisers.
Nemiel felt the rumble of the battle barge's thrusters reverberate through the deck plates as the Invincible Reason went to maximum acceleration. The battle barge and her flanking strike cruisers had adopted a wedge formation, presenting themselves as primary targets to the rebel ships. The Astartes' ships, designed to force their way through a hostile planet's defence network and deploy their landing companies, were even more heavily armoured than typical ships of the line. Jonson calculated that the enemy ships would focus the majority of their fire on the battle barge, buying his other ships precious seconds to close to effective firing range.
'Any response to our hails?' Jonson asked Captain Stenius. They had been trying to raise the Imperial authorities on Diamat as soon as they had come within vox range.
Stenius shook his head. 'Nothing yet,' he replied. 'There's signs of heavy ionization in the atmosphere, though, so we might not get a signal through until we reach orbit.'
'Atomics?' the primarch asked.
The captain nodded. 'It looks like the rebels have launched dozens of orbital strikes, likely targeting troop concentrations and defence installations.'
'Have the rebels succeeded in reaching the forges?' Nemiel asked.
'If not, they must be very close,' Jonson said. 'Otherwise those transports would have broken orbit as soon as we were detected.' He nodded his head at the telltales representing the escorting cruisers. 'They also wouldn't have left behind such a strong reserve force to guard them unless they already contained something valuable, so we have to assume that the enemy has at least managed to breach a number of the planet's secondary forges. If there are any defence forces still in action, they will be concentrated around the primary forge complex and Titan foundry.'
'Titans?' Nemiel asked. 'There is a legion based at Diamat?'
Jonson nodded. 'Legio Gladius,' he replied. 'Unfortunately, their engines are embarked with the 27th Expeditionary Fleet, far to the galactic south. On Horus's orders, I might add.'
'What does that leave the defenders with?'
The primarch paused, consulting his memory. 'Eight regiments of Tanagran Dragoons, plus two armoured regiments and several battalions of heavy artillery.'
Nemiel nodded. It was an impressive array of force. He wondered how much of it still survived. 'What forces can the forges muster?'
Jonson shrugged. 'An unknown number of Mechanicum troops. The scions of Mars are not obliged to share the secrets of their defences.' He paused, studying the plot for several moments before straightening and shaking his head. 'It's looking unlikely that the rebels will detach any units from their main body to try and intercept our escorts. They'll trust the reserve cruisers to keep them at bay, which leaves us facing no less than twelve ships of the line.'
'Ten minutes to contact,' Stenius announced. 'Orders, my lord?'
'Are the Stormbirds ready for another sortie?' Jonson asked.
'We have two squadrons ready for launch, and Amadis reports that they have one squadron standing by. Adzikel has a fire in her hangar bay from a crash-landed Stormbird. They estimate another fourteen minutes before they can resume flight operations.'
'The battle will be over in ten,' Jonson growled. 'Very well: signal the scout force and order them to ready torpedoes and prepare for a course change on my mark. Transmit the same signal to the main force, and add that no ship is to fire until ordered.'
Stenius bowed curtly and began barking orders across the strategium. On the tactical plot the distance between the two fleets was dwindling rapidly. They would be in extreme weapons range within moments. Nemiel thought back to the savagery of the initial engagement and prepared himself for the coming storm.
The main body of the enemy fleet was centred on four grand cruisers; at this range the officers aboard the flagship had positively identified them as the Avenger-class grand cruisers Forinax and Leonis, and the Vengeance-class ships Castigator and Vindicare. To either flank of this powerful group of ships were arrayed a squadron of four cruisers each: a mix of Crusaders, their hulls bristling with weapon batteries, and swift, lance-armed Armigers. Against such a force, the Dark Angels had their battle barge and two strike cruisers, plus the Avenger-class grand cruisers Iron Duke and Duchess Arbellatris and the Infernus-class heavy cruisers Flamberge and Lord Dante. Though the rebels had a clear edge in numbers and firepower, they no longer had any ships capable of launching torpedoes - a slim advantage that Jonson intended to capitalise on.
The seconds ticked by. Captain Stenius watched the readouts on the tactical plot. 'We're at extreme torpedo range,' he announced.
'Not yet,' Jonson ordered. He watched the scout force slip past the main body of the rebel fleet, still accelerating towards Diamat and the vulnerable transports.
Stenius nodded. 'Two minutes to extreme firing range.'
'Any signals from the planet's surface?' Jonson asked.
'Negative,' the captain replied.
'Very well.' Jonson turned to Nemiel. 'If we don't hear anything from the governor or his defence forces by the time we reach orbit, I'm going to send the landing force down around the main forge complex. Your orders will be to secure the forge and eliminate any rebel troops in the area. Clear?'
'Clear, my lord,' Nemiel answered at once.
The battle group sped onwards, straight into the guns of the waiting rebel ships. Two minutes later the Aegis Officer called out, 'Incoming fire!'
'All ships brace for impact!' the primarch ordered.
Lance beams leapt from the prows of the rebel cruisers, raking the void with searing beams of force. They slashed across the prow of the Invincible Reason and the two strike cruisers, causing their shields to flare with incandescent fury. Violet light blazed beyond the reinforced viewports of the bridge and a powerful blow resounded through the hull of the great ship.
'Hull breach, deck twelve, frame sixty-three!' the Aegis Officer called out. 'No casualties reported.'
Captain Stenius accepted the news with a curt nod. 'Do we return fire?' he asked the primarch.
'Not yet,' Jonson replied. He was studying the readout on the plot intently. 'Signal the scout force: come about to new heading one-two-zero and commence torpedo runs on rebel grand cruisers.'
The Astartes ships ploughed through glowing clouds of plasma and vaporised deck plating as they continued to close on the rebel ships. As they closed to optimum firing range the enemy force began a slow turn to starboard so they could bring their fearsome broadsides to bear on the Imperial ships. But as they began their turn, Nemiel saw the scouts begin their course change. The nimble escorts swung around in a tight arc directly behind the enemy ships, their presence hidden by the rebels' own reactor emissions.
The trap had been sprung. Jonson smiled coldly. 'Signal Amadis and Adzikel: target enemy grand cruisers and launch torpedoes. Captain Stenius, you may fire at will.'
More lance shots leapt from the rebel ships, and now the enemy weapon batteries were going into action as well, hurling streams of blazing shells at the oncoming Imperials. At the same time, torpedoes leapt from the tubes of the Astartes ships and the oncoming scout vessels, bracketing the rebel grand cruisers from both fore and aft.
Heavy blows pummelled the battle barge to port and starboard. Alarms wailed. 'Multiple hits, decks five through twenty!' the Aegis Officer called out. 'Fire on deck twelve!'
'Signal the main force,' Jonson said calmly. 'New course three-zero-zero. All units, target enemy cruisers to port. Fire at will.'
Wreathed in a maelstrom of fire, the Imperial ships swung ponderously to port, aiming away from the centre of the enemy formation and instead towards the four rebel cruisers on the enemy's flank. Along the dorsal gun decks of the battle barge, enormous turrets slowly traversed, bringing their massive bombardment cannons to bear on an Armiger-class cruiser. At the same time the battle barge's starboard weapons batteries went into action, hammering at the rebel ship's void shields with a hail of macro cannon shells. The enemy cruiser's shields flickered angrily under the relentless barrage before collapsing entirely. At the same time her lance batteries lashed at the Invincible Reason, raking her void shields from stem to stern. Beams of force pierced the defensive field and clawed through the barge's armoured hull.
Seconds later the battle barge replied with a rolling salvo from her bombardment cannons. They boomed through the hull like war drums, each one growing louder as the volley marched closer to the bridge. The shells glowed as they sped through the void and smashed into the flanks of the rebel ship. Nemiel watched in awe as a series of massive explosions rippled through the cruiser's decks, until finally it blew apart in a flare of escaping plasma.
Farther away, the grand cruisers at the centre of the enemy formation were reeling beneath the blows of Imperial torpedoes that struck them both fore and aft. The Forinax staggered out of the formation, her bridge aflame, while the Castigator saw most of her starboard gun decks smashed by a trio of powerful hits. The scout force reduced speed and continued their run behind the rebels, lashing at the enemy ships with their weapon batteries and energy lances.
The Imperial ships plunged through the rebel formation, exchanging thunderous broadsides with the enemy. The smaller cruisers suffered greatly under the punishing blows of Jonson's larger ships; a Crusader received a broadside from both the Amadis and the Iron Duke that ripped her open and left her a burning hulk, while the second Armiger blew apart in another massive fireball as her reactor core was breached. Lances and shells hammered the Imperial ships as well; the flagship and the strike cruisers bore the brunt of the enemy fire, their armoured hulls riddled with multiple impacts and the glowing tracks of lance hits. Duchess Arbellatris staggered beneath a hail of fire; her hastily-repaired hull plating gave way beneath the onslaught, wracking the proud vessel with devastating internal explosions that left her drifting out of control. Flamberge and Lord Dante suffered as well, their upper decks and superstructure smashed by a hail of enemy shells, but the battered heavy cruisers held their course and returned fire with every weapon they had left.
The exchange lasted barely fifteen seconds, though to Nemiel it seemed like an eternity. The void was rent with fire and streams of blazing debris. Ships and men died in the blink of an eye before the two forces drew away from one another on opposite courses. The scout force continued to harry the rebels as they sped away and began a slow turn to re-engage the Imperial battle group.
'Damage report!' Jonson ordered. The Invincible Reason shuddered like a wounded beast as she sped on towards Diamat. The air in the strategium was growing hazy with smoke as fires spread throughout the ship.
Captain Stenius was bent over the Aegis Officer's station, his augmetic lenses glowing green in the reflected light of the flickering readouts. 'All ships report moderate to severe damage,' he replied. 'Duchess Arbellatris is not responding to signals. Flamberge and Lord Dante report heavy casualties. Iron Duke and Amadis have both sustained damage to their thrusters, and Amadis also reports that her flak batteries are out of action. Repairs are underway.'
'What about us?' the primarch said. 'How hard were we hit?'
Stenius grimaced. 'Our armour stopped the worst of it, but we've got hull breaches all over the ship and a fire raging on three decks. The torpedo deck reports that the forward tubes are fouled, but they're working to clear them.' He shrugged. 'It's not good, but it could have been much worse.'
Jonson smiled grimly. 'Don't tempt fate, Captain. We're not finished yet. Signal the main force to alter course to three-three-zero and launch the Stormbirds. We'll head straight for those transports and see if we can force them to weigh anchor. I'm betting the reserve force will opt to disengage rather than risk those ships.'
He turned to Nemiel. 'Brother, it's time you made your way to the drop pods. We'll be over Diamat in another ten minutes.'