13th Black Crusade (Original) - The Battle of Cadia in Space and Stalemate: The Imperial fleet in orbit of Cadia above the valiant Imperial defenders on the ground was also gathered for its final stand, determined to gain time for the Eldar led by Farseer Eldrad Ulthran to board the Blackstone Fortress and disable it from within. If the xenos proved successful, the Imperial forces might live to fight another day. Should they fail, the world of Cadia and all who stood upon it would be scoured away by the power of the Warp unleashed upon its surface by the Blackstone Fortress moving into orbit above them. This had been Abaddon's plan all along in launching the 13th Black Crusade; everything had led to this particular moment.Soon the battle in orbit was underway. True to their word, the Eldar's potent fleet fought side-by-side with the vessels of the Imperial Navy. The toll taken upon these combined forces of Order was fearsome indeed, but this desperate endeavour was worthy of the greatest of sacrifices, for failure meant that the Cadian Gate would lie open for Abaddon to launch his campaign against Terra and succeed where his master Horus had once failed. The details of the battle in orbit that ultimately saw the Blackstone Fortress defeated are difficult to piece together in the wake of the chaos caused to the Cadian High Command by the Imperial retreat from Kasr Partox. Admiral Quarren, who commanded the Imperial fleet that defended Cadia, reported that the bulk of his fleet was destroyed, many vessels having paid the ultimate price to ensure the Farseer of Ulthwe the time necessary to complete his vital mission. It appeared that the Farseer's vessel, the Isha'ra, penetrated deep through the Chaos fleet's lines, many of its sister warships being destroyed in the action. Once close enough to do so, Ulthran boarded the Blackstone Fortress, and has not been seen or heard from since.At the height of this battle, it is reported that a fleet of Necron vessels appeared as if from nowhere and assaulted both the Blackstone Fortress and the Chaos warfleet. So confused and incomplete are the Imperial records of this engagement that the Cadian High Command may never piece together the true details of how victory was won in orbit. Regardless of their reasons for doing so, the Necron ships forced the Blackstone Fortress to disengage from its approach on Cadia, and contact with it was lost soon after as it fled the Cadian System. The last the Imperial forces knew of what had happened to the so-called "Talisman of Vaul" was reported by a psyker attached to the Cadian High Command's general staff, Lieutenant Fortuna, who was struck down with a vision of Farseer Ulthran trapped within a shimmering crystal, his soul-scream echoing throughout the Warp. No doubt Imperial seers and savants would be looking to unravel this mystery for many years to come.Yet the final outcome of the Battle of Cadia, no matter how it had been arrived at, was clear. The Forces of Chaos had seized a large portion of the surface of Cadia, but the Imperial and Eldar victory in orbit forced the Chaos warfleet to retreat back towards the Eye of Terror, giving the Imperium naval superiority in the Cadia System and the broader Cadian Gate. It provided the servants of the Emperor with the ability to keep the Forces of Chaos contained on the surface of Cadia, where ground operations slowly ground to a stalemate, with neither side able to make headway against the other. While the Imperium possessed air superiority, the Forces of Chaos' sheer numbers prevented them from being dislodged from their occupied territory. Should a second Chaos assault come and break the Imperial blockade, there was little chance that the Emperor's faithful would be able to hold the Fortress World without further reinforcements.