Standing atop the defensive wall, the Warhawks watched as the Venerators leaving the base, many of them not even in any vehicles as they simply sprint towards their targets.
"Prepare the second barrage," the Warhawks Chapter Master ordered, turning towards the Techmarine beside him. "I want the Whirlwinds to fire in twenty minutes."
"As you command, my lord."
The Techmarine activated his wrist-mounted control panel, establishing a connection with the artillery crews stationed behind the defensive perimeter.
"Whirlwind batteries, this is Techmarine Vardan. Prepare for a second firing sequence. Target coordinates will be transmitted shortly. Stand by for orders."
The Chapter Master returned his attention to the battlefield.
The first bombardment had been intended to disorganize the traitor forces, ensuring that when the Venerators struck their defensive line, no reinforcements could arrive in time to disrupt their assault.
The purpose of the second bombardment was different. This time, the Warhawks intended to prevent the traitors from regrouping, reorganizing their defensive positions, or dispatching reinforcements to the sectors under attack.
Every approach leading towards the frontline would be subjected to sustained rocket fire. Enemy command posts, artillery positions, supply depots, and known troop concentrations would be targeted to disrupt their communications and cripple their ability to coordinate a counterattack.
Even if the traitors managed to survive the initial assault, they would find themselves unable to restore their defensive line before the Venerators reached their next objectives.
As the Warhawks made preparations for the second bombardment, a series of explosions suddenly erupted from the eastern side of the fortress. The distant sounds of gunfire followed, quickly growing louder as the fighting intensified.
The Chapter Master turned towards the source of the disturbance.
"What's going on?" he demanded over the vox.
"The traitors are launching an attack against us!" A voice replied almost immediately. "At present, we're engaging cultists and a small number of traitor guards, but our forward observers have spotted several groups of traitor Astartes moving through their trench lines."
The Chapter Master's expression hardened.
"Have they identified the numbers?"
"Negative, my lord. Their numbers are still unclear. They're keeping to the trenches and using the cultists as cover."
The Chapter Master glanced towards the Techmarine.
"How long until the Whirlwinds are ready?"
"Approximately fifteen minutes, my lord. The crews are preparing the second firing sequence."
"Delegate this duty to the Techpriests," the Chapter Master ordered, already turning towards the eastern wall. "Activate the sentries. I have a feeling the Black Legion will launch their attack at any moment."
"Understood," the Techmarine replied.
He raised his wrist-mounted cogitator and began entering a series of commands. Almost immediately, mechanical noises echoed throughout the base. The numerous containers positioned around the defensive perimeter began to stir, their internal mechanisms grinding into motion.
A moment later, their heavy doors slammed open.
Squads of combat servitors marched out in orderly formation. Each had been modified for battlefield deployment, with one arm replaced by a heavy bolter or plasma cannon. Their movements were mechanical and precise, their weapons already primed for engagement. Without hesitation, they took up positions around the base, following the defensive protocols programmed into their systems.
The Chapter Master watched as the servitors deployed before turning his attention towards the eastern wall.
The Warhawks, despite their aggressive-sounding name, were a Chapter whose doctrines placed considerable emphasis on defensive warfare. This had not always been the case. Their present doctrine was born from one of the darkest defeats in their history, a disaster that had cost them their entire 1st and 2nd Companies, along with the majority of their senior officers.
In the aftermath, the newly appointed Chapter Master had undertaken a fundamental revision of their combat doctrine. Rather than attempting to match their enemies in aggression, the Warhawks would make themselves exceptionally difficult to dislodge. They would turn every battlefield position into a fortress, every approach into a killing ground, and every advance by the enemy into a costly undertaking.
The loss of their 1st Company had been particularly devastating. With its destruction, the Chapter had lost its entire stock of Terminator armour and its Land Raiders. Despite centuries of effort, the Warhawks had yet to replenish either arsenal completely. Even now, in 723.M36, they remained without a full complement of Terminator armour or a single Land Raider.
To compensate for these losses and support their new doctrine, the Chapter increasingly relied on defensive assets and automated weapon systems. Combat servitors, Tarantula sentry guns and Hammerfall bunkers became essential components of their battlefield deployments. These machines allowed the Warhawks to establish formidable defensive positions without committing large numbers of Astartes to static duties.
For the moment, however, the Warhawks had only activated their combat servitors. They were more than sufficient to deal with the expendable fodder the traitor Astartes had thrown into the attack. The Tarantula sentry guns and the Chapter's few remaining Hammerfall bunkers remained offline, though all were on standby and could be brought online at the press of a button.
There was no reason to expend their ammunition or reveal the full extent of their defensive arrangements against such an insignificant assault.
By the time the Chapter Master reached the eastern wall, the situation was already half-resolved. The combined firepower of the Warhawks Astartes and their combat servitors had torn through the attacking cultists and traitor guards. Heavy bolter rounds shredded their ranks, while bursts of plasma fire reduced entire groups to little more than ash and molten remains.
The enemy had barely managed to make any progress across the open ground. Most of the cultists had been cut down before they could even approach the Warhawks' defensive perimeter, while the surviving traitor guards struggled to maintain order among the dwindling remnants of their forces.
Yet the Chapter Master paid little attention to the dying cultists.
His gaze was fixed on the trenches beyond them.
The shadows of traitor Astartes could still be seen moving through the trenches in the distance. Though the cultists and traitor guards had been wiped out, the true threat remained concealed among the defensive works.
After a full fifteen minutes of fighting, the last of the cultists and traitor guards finally fell. Their attack had been repelled, at least for the moment.
With the immediate threat eliminated, the Warhawks began replenishing their ammunition. Servitors were guided towards the empty ammunition crates, carrying replacements to the defensive positions or assisting the Astartes in transporting them. Once their duties were complete, the servitors were deactivated and returned to standby.
Nearby, the Techpriests began servicing the combat servitors' weapons. Some worked to replenish the heavy bolters' ammunition feeds, while others replaced the depleted coolant vials used by the plasma cannons. Every weapon had to be ready for the next engagement.
Meanwhile, the Whirlwinds had completed their preparations and commenced the second barrage. However, the Chapter Master had ordered four of the vehicles to redirect their fire towards the trench line from which the previous attack had originated.
He watched as explosions erupted across the enemy positions, sending earth, debris and shattered fortifications into the air. The bombardment swept along the trenches, targeting the locations where the traitor Astartes had last been spotted.
The Chapter Master could only hope that the barrage would delay their next attack long enough for the Venators to complete their operation. Only then would he be able to recall his 5th and 9th Companies, both of which had been assigned to establish the kill-zone as part of the Venators' wider plan.
The Warhawks had arrived in the sector at roughly the same time as the Venators, but their forces had since been divided to reinforce several important systems throughout the region. As a result, only five companies remained directly under the Chapter Master's command: the 1st, 4th, 5th, 7th and 9th.
Even then, the 4th Company remained aboard the Chapter's fleet, while the 5th and 9th were committed to supporting the Venators' operation. This left the Chapter Master with only the 1st and 7th Companies to defend the base.
It was hardly an ideal situation.
The Warhawks had prepared their defences to withstand an assault, but even the strongest fortifications could only do so much when the defenders were stretched thin. If the Black Legion committed a substantial force of traitor Astartes against their position, the Chapter Master would have little room for error.
For now, he could only trust that the bombardment would buy them enough time.
Unfortunately, it seemed that neither the Emperor nor Dorn had seen fit to answer his prayers.
The moment the second barrage came to an end, the traitors launched their attack.
This time, there were no expendable waves of cultists accompanied by a handful of traitor guards. The enemy had committed a proper assault force.
Traitor guardsmen advanced in considerable numbers, supported by armoured Sentinels and Chimeras. Their vehicles moved across the battered terrain, weapons firing as infantry poured out from behind their advancing transports. Heavy weapons teams took up positions among the ruins, adding their firepower to the advancing columns.
And among them were the traitor Astartes from the Black Legion.
Their dark silhouettes could be seen advancing behind the Imperial Guard formations, using the infantry and armoured vehicles as cover. Unlike the previous attack, these warriors were no longer content to remain concealed within the trenches.
Now, they thirsted for battle.
The combat servitors immediately reactivated.
Their mechanical limbs shifted into firing positions as targeting systems locked onto the advancing enemy. A moment later, the defensive perimeter erupted with gunfire.
Heavy bolters roared, unleashing streams of explosive rounds into the traitor guardsmen and the advancing Sentinels. Infantrymen were torn apart as shells detonated among their ranks, while the lighter armour of the Sentinels buckled beneath repeated impacts. One of the walkers staggered as its leg assembly was struck, before collapsing into the mud.
The plasma-armed servitors selected a different set of targets.
Their weapons turned towards the advancing Chimeras, firing concentrated bursts of superheated energy. The first shot struck a transport's turret, engulfing it in a brilliant flash before the entire weapon assembly was blown apart. Another plasma bolt slammed into the front armour of a second Chimera, leaving a glowing crater across its hull.
The servitors continued firing, attempting to destroy the transports or, at the very least, disable their weapons and mobility before they could bring their passengers within effective assault range.
But the enemy advance did not stop.
The surviving Chimeras continued forward, their heavy bolters and multilasers returning fire against the defensive positions. Behind them, the traitor guardsmen pressed on, while the traitor Astartes began to increase their pace.
When the traitor guardsmen finally reached the series of barricades the Warhawks had constructed outside their base, the Tarantula sentry guns automatically activated.
Those equipped with heavy bolters immediately opened fire, unleashing devastating volleys at the approaching infantry. At such close range, the explosive rounds tore through the traitor guardsmen, blowing bodies apart and leaving the ground littered with mangled remains.
The Tarantulas armed with lascannons concentrated their fire on the surviving armoured vehicles. Brilliant beams of energy pierced the battlefield, striking the remaining Sentinels and Chimeras. One Sentinel was struck squarely in its cockpit, the lascannon beam burning through its armour and killing its pilot instantly. A nearby Chimera suffered a direct hit to its hull, the resulting explosion engulfing the vehicle in flames.
Yet the Tarantulas could only do so much.
The traitor Astartes charged through the storm of gunfire, their power armour absorbing impacts that would have slaughtered ordinary soldiers. Some fired their bolters as they advanced, while others hurled grenades towards the automated defences.
The first Tarantula was destroyed when a traitor warrior reached its position and planted a melta bomb against its housing. The explosion reduced the sentry gun to twisted metal and scattered machinery.
More followed.
The traitors moved from one barricade to another, using melta bombs to destroy the remaining obstacles and automated weapons. Their advance was brutal and deliberate, clearing a path for the surviving guardsmen to follow.
The Warhawks' Chapter Master watched the enemy breach their outer defences.
"Activate the Hammerfalls," he ordered.
By then, the traitor Astartes had destroyed the final Tarantula sentry guns. With the automated defences silenced, they began firing their bolters towards the Warhawks' positions, forcing the defenders to take cover.
Suddenly, the traitors felt the ground beneath their feet begin to tremble.
At first, it was barely noticeable. Some dismissed it as the aftershock of the ongoing battle, while others struggled to maintain their footing as they searched for cover from the incoming bolt rounds.
Then the ground exploded.
Several sections of soil erupted upwards, sending dirt and debris flying into the air. Beneath the disturbed earth, massive defensive structures emerged from their concealed positions.
The Hammerfall bunkers had been buried beneath the soft soil, their presence concealed until the moment they were needed.
Their weapon systems activated almost immediately.
Heavy bolters roared from the newly exposed bunkers, unleashing devastating volleys into the traitor Astartes at close range. The sudden appearance of the weapons caught the attackers off guard. Several warriors were struck before they could react, their armour battered by explosive rounds.
The guardsmen following behind them suffered even worse. Caught in the open, they were torn apart by the overlapping fields of fire, their ranks collapsing beneath the sudden barrage.
Missile launchers emerged from the bunkers' weapon housings, their targeting systems locking onto the remaining armoured vehicles and concentrations of enemy infantry.
This was one of the tactics the Warhawks favoured.
The mere presence of Hammerfall bunkers was often enough to make an enemy commander think twice before committing to an assault. Their heavy weapons and formidable defensive capabilities made them dangerous obstacles to overcome.
But the Warhawks understood that an enemy could not prepare against a threat they did not know existed.
By concealing their Hammerfall bunkers underground or disguising their positions among the surrounding terrain, they could allow an advancing force to approach before revealing their true strength. The sudden appearance of the bunkers would catch the enemy off guard, maximising the damage they could inflict before the attackers had time to react.
And that was precisely the punishment the traitors were experiencing now.
At the same time, the eastern gate of the base swung open.
The Vanguard Veterans of the 1st Company charged out, their chainswords roaring as they descended upon the surviving traitors. Bolt pistols barked in rapid succession, their shots striking the exposed guardsmen and other vulnerable targets. The Veterans moved with practiced coordination, cutting down anyone who attempted to resist.
Caught between the fire of the Hammerfall bunkers and the sudden counterattack, the remaining traitors were quickly overwhelmed.
Before long, every enemy soldier who had managed to cross the barricades had been killed.
The attack had been repelled.
Once the fighting ended, the Vanguard Veterans began withdrawing through the eastern gate. Those still manning the walls returned to their positions, while the servitors and Techpriests started the familiar process of replenishing ammunition and servicing the defensive weapons.
Then came another sound.
A deep mechanical rumble emerged from the direction of the trenches.
The Chapter Master stopped.
Around him, several Astartes and even the returning Veterans turned towards the source of the noise. Their movements gradually came to a halt as they watched the distant trench line.
Behind it, the silhouettes of armoured vehicles began to emerge.
Leman Russ battle tanks.
And, far worse, the Chapter Master could make out what appeared to be the unmistakable outlines of Land Raiders among them.
The trenches that had seemed almost deserted after the previous attack were now filled with activity once more. More traitor guardsmen were taking up positions, while additional groups of traitor Astartes emerged from their concealed positions.
"Divert more of the Whirlwinds to engage them," the Chapter Master ordered over the vox. "Destroy as many of those armoured vehicles as possible before they reach our defensive line."
He continued watching as the enemy armour advanced.
The Warhawks had already committed most of their available forces. Their outer barricades had been breached, their automated defences were being depleted, and the Chapter Master had only two companies directly available to defend the base.
Now, the Black Legion was bringing in more armour and more Astartes.
He tightened his grip around the hilt of his power sword.
"This may be our last stand."