While Battlegroup Apocalypse began the invasion of Bastien the forces of the Imperium were in action across the Perseus Deeps to protect the flanks of this latest thrust. Three separate operations were undertaken to bolster the Bastien invasion, against three different foes, the intention being to prevent any of these enemies of the Imperium putting the invasion of Bastien in jepoardy.
The Blood Drinkers chapter were in action once again, this time conducting a lightning raid on Aornis, the closest planet of the chaos empire controlled by Moonface. Forces were dropped following a bombardment of the planet's major settlement although at first it seemed the raid - intended to inflict maximum damage on the Catechism - would be a failure, as the Blood Drinkers landed some distance from the rebel guard units defending the settlement. However the astartes forces quickly made up the ground, braving heavy gunfire, before falling upon the Catechism forces and inflicting a large amount of damage to the installations on Aornis which would prove critical if Moonface decidded to come to Bastien's aid.
Meanwhile on Gamordal, the most heavily fortified Ork planet in the Deeps, Cereberex guard units were deployed to expand the bridgehead secured by the Blood Drinkers in the previous week. Once again the Cereberex loyalistsproved their worth, delivering a crushing blow to the Ork forces of Da Verminator and taking three key Ork settlements, breaking the Orks' main defensive line. By 1005.010M42 the Imperium had managed to secure more than half the inhabited settlements of the minor planet, putting several hundred thousand greenskins to death and routing the remaining enemy forces.
The Blood Angels arrived at Minos, a Tau minor colony beseiged by the Imperium a day later, but found the Tau prepared and ready for their landing. With only 500,000 Tau on the planet conquered by commander Fastblade in 008M42, it seemed as if the Blood Angels, though small in number, would defeat the alien defenders with their superior fighting prowess. However a new commander had recently arrived, undetected by Imperial intelligence, which significantly bolstered the Tau defences. In a savage battle outside the single Tau settlement the Blood Angels were comprehensively defeated and forced to abandon their mission without inflicting significant damage, and only narrowly avoided the returning Tau fleet - also unknown to the Imperium until this moment.
In general, despite the reverse suffered on Minos, the Imperial operation against the Imperium's most dangerous foes had been a success, while the forces of Chaos faced a much tougher challenge in their attempts to secure dominance in the region. An ill fated mission by the Anticross to raid or set up a base on Gamador only brought more gloom to Lorek on Bastien. With further troops preparing to disembark to consolidate the bridghead on Bastien, now everything rested on the claws of Lorek and their allies being able to halt, and reverse the imperial crusade.