Medusa V - Exterminatus: For two and a half standard years, Medusa V's hastily raised army kept the citizens of Medusa IV still loyal to the Emperor from being totally overwhelmed, turning back one assault by the Chaos Cultists after another. Eventually, the defenders knew there could be no true victory against such odds, not even when the Warp Storm finally dissipated and the 2nd Company of the Ultramarines Chapter was at last able to come to the planet's aid.The Inquisition desptached its agents to ascertain the scale of the Medusan IV heresy and eventually, regrettably, the Inquisition determined that Exterminatus was the only viable solution.The Cult Mechanicus and the Adeptus Administratum lobbied the Inquisition agents monitoring the schism to suspend the sentence just long enough to allow what Loyalist citizens remained on Medusa IV to be evacuated. Tithe forecasts and resettlement schedules showed the crippling effect leaving them to die would have on industry in the sector, so the Inquisition granted a one-week stay of execution.Millions of Loyalists were loaded onto transports normally used for shipping foodstuffs to Medusa IV and a mass exodus of the Loyalist hive cities began. While the Ultramarines and the PDF regiments of Medusa V fought a heroic rearguard defence against an endless horde of insane Chaos Cultists, those innocents that could be saved were ferried off-world to Medusa V.Even the Astartes could only prevail so long in the face of such overwhelming numbers and unreasoning hate. Finally they too were forced to withdraw, leaving the Heretics and remaining civilians to their fate. A sleek Inquisitorial covette under the command of Inquisitor Baptiste fired a single salvo of Cyclonic Torpedoes at the planet, a deadly payload of the variant known as Atmospheric Incinerator Torpedoes.The warheads ignited the oxygen-rich atmosphere of the planet in a massive thermonuclear reaction, devouring everything in a blistering conflagration that seared all signs of life from the world, turning metal into molten slag and rock to glass as the Inquisition's fiery judgment took its toll.The planet burned brightly for a whole solar month, and from the safety of their own world, the people of Medusa V looked on in awe as their neighbour was consumed in the purifying flames of the Emperor's justice. Those Loyalist citizens of Medusa IV who had escaped offered prayers of gratitude to the Emperor for their deliverance.The new residents of Medusa V arrived from their burning planet by the millions and were welcomed by the waiting agents of the Inquisition's Ordo Hereticus. A drawn-out process of screening to root out any Heretics amongst the refugees commenced and many thousands found their way to the pyre as the Inquisition acted ruthlessly to ensure the future purity of Medusa V.Colossal prefabricated cities were hastily erected by the Adeptus Mechanicus, vast structures that could house millions upon millions. Into these makeshift hive cities the refugees from Medusa IV were herded in droves, kept separate as a precaution against the spread of heresy.These "refugee cities," grim edifices of steel and stone, gradually found their place within the society of Medusa V, providing a vast new labour force to work the ore extracted from the mining world's crust.In only a few standard years, Medusa V found itself producing more promethium fuel, metals and supplies than it had ever been able to manage before the arrival of the refugees from Medusa IV.