Scourging of Kerrack - The Roots of Heresy: Kerrack is a peculiar world where life has always been harsh. The planet is dominated by a single large continent where the human population has naturally concentrated. This vast continent harbours Kerrack's single and most valuable resource: the great forests of mighty Cholam trees, some of them towering more than 200 Terran feet in height. Cholam roots only grow in humid environments, which means that beneath the canopy much of Kerrack's continent resembles a gigantic swamp. Although filtered through ancient technological artefacts that likely predate the birth of the Imperium, the water used to irrigate these forests is highly toxic. The Imperial presence on Kerrack is concentrated in a few factory-cities located on the shorelines. The harvested Cholam roots are processed there into a barely palatable but nutrient-rich grey gruel, before they are shipped to Kerrack's single spaceport at Ven Nys and then on to the overpopulated Hive Worlds across the Imperium and to support the Astra Militarum regiments engaged in the Karthago Crusade.Since its establishment as an Imperial Agri-world, Kerrack's native population has deliberately been kept in a state of servitude and held to a lower technological standard than that of the wider Imperium. Organised in great family-groups, the men and women of the so-called Harvester Clans have toiled under the stern gaze of their Imperial overseers, hacking at the tough, fibrous roots of the Cholam trees. So thick were these forests that only travel on foot was possible, thus severely hindering quick transport of goods and personnel on Kerrack. Clansmen riots and insurrections were few and far between, though not unheard of. So in 926.M41, when the first clansmen rose against the Imperium, none could have foreseen the dramatic turn that events would take.Upon learning of the first uprisings, Kerrack's Planetary Governor Vortgern Strick immediately ordered the Planetary Defence Forces to mobilise. His intent was to quickly smash the riots, but like a brush-fire, these revolts spread quickly, including amongst the PDF. All across the northern shore of the continent, from Algrist in the west to the Ven Nys spaceport in the east, all of the Imperial settlements came under attack, be it from the great mobs of Harvester Clans, now openly declaring themselves the "Charnel Cult" or insurrectionist elements of the Kerrack PDF. At the planetary capital of Calder's Ark, Governor Strick quickly found himself besieged in his own palace. Fortunately for the Governor, a sizable Astra Militarum garrison had been stationed at Calnix Island, to defend the Adeptus Administratum-controlled weapons and munition depot. There on "Fortress Calnix," Colonel Mortemar and his three thousand Cadian Shock Troops readied themselves for their decisive counterattack.For the Imperial defenders, things looked grim. Colonel Mortemar knew that the enemy heavily outnumbered him. If he was caught in the open, his troops would be quickly annihilated. Secondly, the Cadians were only able to field about two hundred aircraft, not enough to deploy the Cadian forces as one, which would mean that his already meagre fighting force would need to be further divided to allow them to reach the designated battlefield. Furthermore, such large landings could only be conducted in the great factory-cities, most of which had already fallen to the enemy. A direct assault on Calder's Ark was deemed too risky, and so Colonel Mortemar settled for the capture of Algrist, the nearest settlement from which he could strike at the capital, break the siege of the Governor's palace and rally enough loyal troops to finally put down the rebellion.In disciplined ranks and files, the brave Cadians boarded what Valkyries were available. A first group would storm the city, dig in and hold out against the enemy until a second wave of Loyalist troops could be ferried from Calnix Island. To improve the chances of the first assault wave, it would be supported by what aircraft the base could muster to serve as both air defence fighters and tactical air support. While Mortemar's strategy was sound, on the ground and in the air, things looked far more complicated.First was the nature of the terrain. Like many provincial cities within the Imperium, Algrist was no grand planetary capital with wide avenues, grand plazas and elegant official buildings: it was an industrial town at the heart of a dense forest. Algrist's streets were narrow and its skyline dominated by the great bulk of the processing factories and worker habs which would take many hours of fierce street-to-street fighting to seize. The height of the Cholam trees -- some of which can grow to a height of more than 200 Imperial feet -- also meant that any approaching aircraft could not use the natural terrain to hide from the city's air defences, which would presumably be well manned by the Charnel Cult. Capturing Algrist would make for a dire prospect indeed.To make things worse, as soon as the Imperial counterattack was launched, it ran into the enemy. Before even reaching their designated target, the Lightning Strike Fighters of Leonid Squadron who served as the spear-tip of the Imperial attack encountered unexpected enemies: defiled Thunderbolts of the Charnel Cult, formerly belonging to Kerrack's Planetary Defence Forces. Heavily loaded with bombs, as their prime target had been Algrist's anti-air guns, the normally nimble Lightnings made for easy targets. Intercepted while still over the Calnix Channel, a fierce dogfight erupted from which the Imperial fighters ultimately emerged victorious, but several of their numbers had been damaged or been forced to drop their payload into the sea and thus needed to return to base. The depleted first wave continued their attack, approaching Algrist from the sea. The Lightning pilots valiantly dropped to a dangerously low altitude, using the city's drainage trenches and channels as approach vectors to find their target. This allowed the Imperial pilots to close with their target while limiting their exposure to enemy fire, but also required the pilots to level out at the last possible moment, only narrowly avoiding crashing into the city's towering nutrient processing facilities. One pilot miscalculated his approach, pulled up too late and crashed at full speed into the city's ferrocrete flood walls. Forewarned of their approach, the Lightnings were welcomed by Autocannon and Manticore-platforms that spit fire from the ground.Having been delayed by their unexpected skirmish above the Calnix Channel, the Imperial aircraft were still dealing with Algrist's air defences while the first wave of Mortemar's troop were inbound, further crowding the airspace. The Thunderbolts that made up the first wave's fighter escort soon gained altitude to engage their Renegade counterparts, while the infantry-laden Valkyries sped on. The heavier Vulture gunships outpaced the vulnerable transports, attacking the buildings surrounding the landing zones to keep the enemy occupied or being occasionally called in to destroy an enemy position previously missed by the Lightnings of Leonid Squadron. With typical diligence and the routine born of many battles, the Cadians rappelled down their transports' lines and immediately rushed into buildings, clearing out the enemy to secure a proper beachhead. Fierce firefights and heavy fighting erupted in the city's eastern quarters.As soon as they had off-loaded their human cargo under the watchful eyes of their escorts, the Valkyries turned and raced back to Calnix Island where the second wave of Imperial troops waited to be ferried to the mainland. The Lightnings and Vultures remained on station, the Cadians ordering precision strikes wherever the enemy resistance was too tough to break, but their fuel was limited. The enemy would counterattack once the Imperial air support was forced to quit the battlefield, so the Cadians did not heedlessly rush in, but instead fortified their landing zones, waiting for the arrival of their reinforcements to properly take control of the city. As predicted, the Charnel Cult launched themselves at the Imperial attackers with great savagery, but the Cadians held their positions until the arrival of the refuelled Valkyries and Thunderbolts heralded the cultists' defeat. By the end of the day, Algrist was once again in Imperial hands.