13th Black Crusade - War in the Void: While the war continued to go badly upon the surface of many worlds in the Cadian System, in particular Saint Josmane's Hope and Solar Mariatus, the war in space was fought more on the Imperium's terms. The Cadian System had been the focus of Abaddon's primary fleet actions, and the Imperium's fortunes there changed from day to day. The situation was highly fluid and the Chaotic naval forces found themselves stretched to exploit the victories they had won. Although the Imperial Navy's fleets could not hope to oppose those of the Archenemy in and around the orbital space of most of the worlds of the Cadian System, they continued to hold on to control of the inter-system space lanes within the Cadian Sector. The Imperium could not under any circumstances afford to let their guard waver, for it was upon one of these routes that they hoped to bring the Planet Killer to battle. To let it past was too terrible a failure to contemplate.A fleet the size of which has not been seen since the end of the Gothic War eight standard centuries earlier had been despatched from Cypra Mundi, and arrived at Belis Corona in preparation for a massive Imperial counter-offensive into the Cadian Gate. The arrival of this vast armada allowed those Imperial vessels that had been fighting continuously since the beginning of the invasion a brief respite. Severely depleted ship's companies were bolstered through indiscriminate press-ganging, and hasty repairs and refits were undertaken on those vessels most in need of them.The Imperial reinforcements were split into battlegroups, each tasked with bolstering the defences in a specific sector of the Segmentum Obscurus. The regions around the Eye of Terror encompass many millions of cubic light years, and only by the concentrated application of resources in those areas in most desperate need could the Imperial Navy hope to make inroads and slow, stall, and eventually repel the Chaos warfleets plaguing the region. During the latter stages of the campaign, when Abaddon's fleet was seen approaching the Agri-world of Lortox, the Ultramarines Honour Company distinguished itself with a bold, spaceborne counterassault against Abaddon's fleet as the Planet Killer closed with that Imperial world on the outskirts of the Agripinaa Sector. The action bought Lortox's Planetary Defence Forces time to evacuate a significant proportion of the population before the world was destroyed by Abaddon's horrific weapon of planetary destruction. The Ultramarines Honour Company managed to succeed in crippling the Planet Killer, but the massive vessel still had enough power to limp away. In the aftermath of the Lortox Evacuations, the Ultramarines Honour Company redeployed to Cadia and the surrounding star systems, launching a series of operations to hinder Abaddon's forces as they assaulted the Imperial positions. These attacks included a series of highly successful boarding actions against the lumbering Space Hulks being used to transport vast hordes of the Archenemy's troops to reinforce Abaddon's siege of Cadia.It was a fool's dream to hope the Planet Killer could be found before it was brought to bear upon the Imperial forces. Without warning, it appeared in orbit over the world of Macharia. Though many could scarcely believe it, the world was destroyed by the massive vessel. It was lost, and with it millions of loyal and faithful subjects of the Emperor, dead at the hands of the Despoiler and his despicable weapon. Utter dread now descended upon the Segmentum Obscurus High Command. Despite the successes of the early solar weeks of the invasion, many had come to believe that this war might not be won in the short term. Where at first the Imperial forces fought to repulse Abaddon's assault, to deny him footholds upon Imperial worlds, they now fought to keep him from overwhelming them entirely. This was a grim paradigm, and one the Imperial forces were not ready to accept. They believed Abaddon dare not destroy Cadia, as its pylons were reckoned intrinsic to the continued stability of the Cadian Gate which he needed to move his forces deeper into Imperial space so that he could launch an assault upon Terra. So the Imperium would make its last stand upon Cadia and hold that world, no matter the cost.