This is a long piece, so I have split it over two posts. Part two will follow tomorrow.
Finn Keys was the captain of the 10th company and was responsible for the recruitment and training of future Exigators. Although the Exigators were a fleet-based chapter, with their companies split up and assigned to different roaming missions, their principal recruiting centre was on Insolitus in the Halasus Marches. There they encouraged warrior lodges amongst the population and chose the best as recruits for the chapter.
When the Imperium learned of the chapter's gene debasement they developed a two pronged solution. The main thrust would be against the Exigator's fleet at Knardlone, with a smaller but no less vital attack against the scout company, and Finn Keys, at the fortress of Orbis hill on Insolitus.
Inquisitor de Fire was tasked with the mission. The initial bombardment began as planned; lance strikes and melta torpedoes reduced the chapter fortress to rubble. His ground assault, consisting of almost two hundred Stormtroopers flying in on Valkyrie airborne assault carriers supported by Vulture gunships, was delayed for a crucial ninety minutes by unseasonal electrical storms which grounded the flyers north of Stolidus wood.
Astropath M'Kellan survived the devastation of the fortress and received a warning about the destruction of the fleet from the astropath aboard the Swift Justice. He relayed this to the rest of the survivors, some forty scouts and seventy surfs and servitors. They had just enough time to crowd aboard three Thunderhawk gunships, safely housed in bomb-proof bunkers deep below ground. As they roared away from their ruined fortress the Vultures came screaming in. After a short but intense dogfight two Thunderhawks were destroyed in spectacular explosions and the third was forced to splash down in the Rhodahnus river. It sunk to the river bed and 27 bedraggled survivors, including astropath M'kellan and 16 scouts were eventually captured by de Fire.
Following the dogfight, Valkyries deposited the Stormtroopers directly onto the remains of the fortress. They scoured the rubble for the body of Keys but their prime target could not be found. Inquisitor de Fire began aggressive questionning of his captives. Astropath M'Kellan broke under interrogation and revealed that the 10th company captain was out on manoeuvres in the Devil's Den with twelve of his most promising aspirants. M'Kellan tried to send a psychic warning to Keys but he died with the strain, before he could be sure that the message had reached it's target.