Scourging of Kerrack - The Harvester's Doom: As the fighting ebbed at Ven Nys, Colonel Mortemar and his survivors were finally able to meet with their saviours. Captain Calphax personally came before the battered men and women of the Cadian regiments and thanked them for their continued efforts in safeguarding the Emperor's domains. Although the Star Phantoms' 5th Company was bound by duty and honour to return quickly to the Karthago Crusade, the Star Phantoms would not permit Chaos to emerge victorious from this war and claim Kerrack as their own. Kerrack would be denied to the forces of Chaos, no matter how high the cost to the Astartes. Even after the severe losses inflicted upon the enemy at the spaceport, the Charnel Cultists still greatly outnumbered the Imperial defenders. Despite the presence of this new Imperial force on Kerrack, the tactical situation remained unchanged: Mahaur's army still occupied all of Kerrack's major cities and even the Loyalists' control of the spaceport would have to be surrendered in the face of a counterattack. Lacking both the time and the numbers to take back each city, the Star Phantoms decided to concentrate their efforts on eliminating Mahaur and his warband, the Slaughterkin. Following this decapitation strike, the leaderless hordes of the Charnel Cult could be fought by later reinforcements or those troops already present on Kerrack.Although an assault on the capital of Calder's Ark offered them their best chance at a swift and decisive victory, the Imperial commanders were well aware that this plan also presented considerable risks. The former planetary capital had likely been heavily fortified, if not by the ill-disciplined cultists, then at least by the more experienced warriors of the Slaughterkin. As with most Chaos uprisings, the mortal servants of the Dark Gods tended to deify and venerate their so-called liberators, and so it was safe to assume that a large congregation of Charnel Cultists would also be encamped at Calder's Ark. If their attack failed to meet its objectives, the Imperial soldiers and Space Marines would quickly be overwhelmed and none would remain to oppose the Harvester. Captain Calphax assured Colonel Mortemar and his command staff that the Fires of Salvation had been specifically tasked with harassing the enemy in orbit to prevent an assault by the Chaos fleet. While the Star Phantoms gathered in prayer, ammunition and spare parts were ferried from the great depots on Calnix Island to Ven Nys. The Star Phantoms' assault on Calder's Ark would be supported by every last Imperial fighter, bomber, transport and soldier still in decent condition to fight. Having reconsecrated their weapons and their souls to the service of the Master of Mankind, the Star Phantoms boarded their Thunderhawks and quickly departed.As the pearl-white Astartes gunships approached their target, none of their passengers would have recognised Calder's Ark as the proud Imperial bastion it  had once been. Except for the Governor's Palace, where the mangled corpse of its loyal defenders had been strung up like ornate gargoyles, the city was in ruins. Blood-soaked hordes of screaming Charnel Cultists now prowled its streets like predators on the hunt while above the city the sky was filled with the cruel shapes of Hell Blades and Hell Talons, circling above it like a flock of carrion-birds hungrily eyeing a fresh carcass. These Slaughterkin fighters were the first to see their enemy's arrival and immediately converged on them. Beset from both ground and air, even the Thunderhawks' thick armour plating would not hold out for long. Fortunately, the Star Phantoms were not alone. The remaining Imperial air squadrons turned the tide, their timely arrival scattering the Renegade aircraft and allowing the Thunderhawks to touch down and deploy the 5th Company. The Star Phantoms had landed amongst the rubble that were once the central districts of Calder's Ark. With their armoured vehicles to the fore, the Star Phantoms quickly began to move in the direction of Mahaur's stronghold, the roaming bands of Charnel Cultists they encountered barely breaking their stride. The final battle for Kerrack had begun.Meanwhile, the brawl in the air over Calder's Ark was reaching its climax. In the confused melee of darting aircraft, only the lightning-fast reflexes of the most experienced human pilots would see them through this fight. None dared confront the Thunderhawks and their mighty firepower, but the sizeable gunships were slow to turn and the enemy capitalised on the greater manoeuvrability of their fighters. It was in this nightmarish scene that the last wave of Imperial aircraft arrived: the Valkyries carrying Colonel Mortemar and his Cadian Shock Troopers. Long inured to the dangers of flying into the teeth of hell, the Valkyrie pilots fearlessly dived, delivering the Imperial Guardsmen directly into the developing firefight. Soon, the battle raged all over the former capital, the Star Phantoms unleashing the terrifying firepower their Chapter was famed for, only the two force commanders had yet to show themselves. While his battle-brothers persecuted the war on the ground, Captain Calphax and a hand-chosen squad were still in their Storm Eagle, waiting for the Harvester to show his ugly head. Despite the fierceness of the fighting, the enemy commander had yet to be seen. Knowing that the advantage of surprise was soon to be lost, Captain Calphax sought out Mahaur to slay him personally. The Storm Eagle's powerful Vengeance Launcher blasted a path through the palace's defences. Finally unleashed, Captain Calphax vented his fury on those Slaughterkin that tried to bar their way. From the highest tower of the Imperial complex, the Harvester observed his men being slaughtered, his ornate armour easily standing out.When Calphax finally reached the top of the tower, the Master of the Slaughterkin, the polished bones of his victims bedecking his Power Armour was ready, his Power Sword drawn. As the Star Phantom and the Harvester clashed in a blur of powered blades and plasma bolts, the darting aircraft above mirrored the fight below. The Hell Blades sought to pierce Thunderhawk armour while Avengers shot down dozens of Hell Blades with a stream of shells delivered by their Avenger Bolt Cannons. Finally, Mahaur fell, caught in a crossfire unleashed by the Star Phantoms around Captain Calphax, yet he did not die. As he fell, Mahaur's grievious wound began to bubble and expand. Soon the Harvester was convulsing, grasping at his mutating flesh as his body mass began to swell. New eyes and fang-rimmed mouths opened up, leaving the once-mighty Chaos Lord a mewling, slithering mass of mutating flesh. Mahaur the Harvester's failure had angered his dark masters and they had transformed him into a Chaos Spawn as a visible sign of their discontent. Although Mahaur no longer posed a threat, the fighting did not ebb. Seeing their master brought low, the remaining Slaughterkin launched themselves at the Star Phantoms, seeking vengeance upon them. In a disciplined fashion, the Star Phantoms retreated back to their Storm Eagle, paving their way with enemy dead. As soon as Captain Calphax stepped onboard, he gave the order for all Imperial fighters to unleash everything they had on the Governor's Palace.As the Storm Eagle soared away, the former seat of Imperial power was engulfed in a thundering conflagration, as bombs fell on the complex while the Thunderhawks brought down Palace's curtain wall with their Thunderhawk Cannons and Turbo-Laser Destructors. Banks of missiles were fired at the benighted structure, bathing it in flames until it collapsed upon the remaining Saughterkin, consuming them in the raging inferno. The profane thing the Harvester had become died with them, screaming its agony from a dozen throats. Seeing the destruction of their allies and their lord's stronghold, the remaining Cultists were filled with fear, and the Charnel Cult soon fled the battlefield, seeking shelter in the near-endless forests of Kerrack. The battle for Calder's Ark and the whole of Kerrack had been won.