Libria System: Crusade Mechanicus fleet forced to abandon mission to Libria III

Following on from the successful exploitation of the Hadron Expanse by the imperial task force, the adeptus mechanicus found itself with a number of valuable tech hauls from the unexplored region, which included several hulks of old warships. Inquisitor Natalia Vorushko was keen to ensure that the Magi who oversaw the acquisition of the archeotech from the task force was aligned to her Crusade in Libria. This she managed by adeptly ensuring that her faction were in the ascendency at the Hadron jump point in the system of Brimlock, where the task force returned on 1803.016M42. Inquisitor Huron, although disappointed that the disagreement between Vorushko and Hathek was still going on, was obliged to turn over the items of value to the adeptus mechanicus representative Vorushko had made sure was waiting for him.

In exchange for this valuable prize, the adeptus mechanicus agreed to Vorushko's request to break the seige of Libria III. Since late 016M42 the inner system and jump points of the Libria system had been controlled entirely by the alliance. The Federal fleet and the Iron Warrior fleet of Apollo had locked down access to the inner systems leaving Vorushko unable to launch orbital strikes. Even the fast moving vessels of the Minotaurs and Apocalypse Riders had been unable to penetrate the defence screen since Apollo had changed the way patrols were conducted. Libria I, II and III were effectively cut off.

By mid 03.016M42 the Iron Warriors fleet had left the system to be replaced by admiral Swiftstar's tau. The federal fleet had also left, as it had formed the vanguard of the voyage to the Hadron Expanse and not yet returned. Now was a chance to strike at the weakened alliance defence, but Vorushko's crusade was in no position to do so. The astartes had few vessels, and the Crusade fleet under Cornellius and rear Admiral Fernando was undergoing repairs and trying to re-organise at Caitlen Station - which had effectively fallen to Crusade control without a shot being fired.

With no fleet to exploit what would surely be a transient weakness in the alliance defence, Vorushko requested that a mechanicus fleet break the siege. Such a fleet was already available and had been in the area for months, but until now, direct confrontation with the alliance on behalf had been avoided in favour of conducting augur scans of the Mab Nebula.

On 2203.015M42 the Adeptus Mechanicus crusade fleet arrived in the Libria system from an unexpected anlge, using their advanced technology to warp directly into the inner system. Taken by surprise Swiftstar hastily assembled his fleet to face the intruders in the solar flare region of the Librian system.

Throughout the engagement both sides were plagued by poor communications from the radiation constantly streaming from the Librian sun. It was difficult for both sides to coordinate ship movements and targets, and often captains had to attempt to guess their admiral's wishes. This reduced the effectiveness of tau ordnance strikes with torpedoes and manta bombers, but critically affected the coordinated use of the mechanicus nova cannon, which fired at escort vessels for much of the engagement.

Swiftstar formed his infamous "box" formation and faced the mechanicus head on, while the crusade fleet simply accepted the challenge and sailed towards the tau. A vicious close firefight erupted, destroying one mechanicum light cruiser and crippling two more, forcing them to flee the battle. then the Mechanicus fleet managed to utilise a lull in the storm of radioactive particles to coordinate a devastating strike on the tau custodian class battleship "Vigilence". the vessel took the full force of the imperial fleet, and within minutes of being fired upon the tau vessel exploded as her plasma drive containment failed, killing admiral Swiftstar.

Hungry for revenge the tau uncharacteristically closed still further, swarming their mantas around the two dominator class cruisers at the back of the mechanicus formation, reducing both to hulks before one blew up in a spectacular display of pyrotechnics. The mechanium fleet was able to heavily damage a protecter class vessel before both sides lost contact in the mass of swirling plasma, but despite killing the tau admiral and destroying their flagship, the mechanicum fleet had taken more damage, having only an undamaged battleship and two badly damaged light cruisers following the battle. Unable to loosen the alliance grip on the core systems of Libria, the mechanicum fleet disengaged and headed for Caitlen station to repair and refit.