Agathean Domain - Horus Heresy: By the closing days of 006.M31, following the fall of the worlds in the Cyclops Cluster, local Imperial powers were girding for war. Though still distant from the front lines of this new civil war that now ravaged the domains of the Imperium, the leaders of the Agathean Domain knew that they could not stand alone against the might of the Warmaster Horus' Traitor Legions and the forces he had already arrayed behind him. So it was that when Grand Admiral Ospheus LaBray called for a mustering of Loyalist vessels at the Armada Imperialis base at Port Maw, the Agathean Domain sent out a full cruiser squadron bearing the best of the Agathean Domain to reinforce the gathering warfleet.Severely damaged during the Treachery at Port Maw, the surviving Agathean cruiser, the Telemachus, limped back to its homeworld bearing word of Horus' victory and the betrayal of the Emperor by the Cyclothrathine Mechanicum. On board the Telemachus also rested the stasis-held corpse of her former captain, Jocasta MaSade, granddaughter of Ireton MaSade.Despite being mortally wounded, she had valiantly refused to be treated as long as her ship was not yet safe and successfully escaped pursuing elements of the Traitors' fleet before succumbing to her wounds. The arrival of the Telemachus would spark the powder keg of fear and political divisions that had been fermenting on Agathon.Agathon's isolation had protected it from the Warmaster's gaze because as a relatively minor Hive World compared to those of the nearby Manachea System it held little strategic value and had hence been completely bypassed by the Traitors' armed forces. The fear inspired by the fate of such neighbouring worlds as Manachea or Moab grew into civil unrest until even Agathon's Parliament of Electors slipped into open conflict.Debates raged between die-hard Loyalists, those that would cast their lot with Horus in fear of the consequences of not doing so and those who would secede entirely from the Imperium and return Agathon to independence. Blackmail, threats and assassinations were rife as the wheels of the Agathean government became paralysed and the Hive World teetered on the precipice of all-out civil war.Into the warring chamber of the Parliament of Electors came Ireton MaSade, nearly two Terran centuries old and almost a recluse for two solar decades. He had not come alone, for behind him was the body of his granddaughter, carried upon an anti-gravitic, floating stasis bier and flanked by a troop of Solar Auxilia Velitaris armoured in a livery of ice white in deference to Agathon's traditional colour of mourning.Stunned into silence by this most unexpected appearance, the Chamber of Electors was forced to listen as Ireton MaSade spoke, first of grief and sacrifice, then of the dream of the Imperium, of Human unity and the Imperial Truth. As his oratory turned to rage at the moral weakness of his successors, he denounced the Parliament and declared them traitors to the Emperor as the funeral guard turned their Volkites on them and burned the fractious noblemen to ashes.Agathon and the other worlds of the Agathean Domain would be placed under martial law and controlled by the "Old Guard" of the 60th Expeditionary Fleet and their direct descendants. Almost immediately, Agathon's economy and society were put on a war footing not only in order to defend their Domain but to mount an attack on the Traitors. One way or another, Ireton MaSade would have his vengeance, no matter the cost.