Battles rage over Mordecai

While the Imperium faced stalemate at Hexis and were suffering defeats at Paradorn, the Imperium continued their offensive against the most powerful chaos system in the Perseus Deeps, Mordecai. To Lord Maximus, this made sense. Continued pressure at Mordecai would focus Chaos attentions there, as losing Mordecai would cause a major setback to chaos plans across the sector, especially as it was a vital naval base. However, there were others in Maximus' command who suggested abandoning the Mordecai offensive in favour of defending Mordecai and overcoming Chaos at Hexis. The new lord commander dismissed these views, stating that Hexis was too far from Imperial supply to reach a swift conclusion, and the the eldar attack at Paradorn was being supported by chaos fleets. Destruction of the chaos hold on Mordecai was a strategically sound decision.

In order to soften up the defences of Mordecai Primaris, which were significant, the Imperial Fleet of Admiral Dreyer was sent in against the chaos fleets patrolling the outer reaches of Mordecai. Dreyer took command of most of Hughes' torpedo armed vessels as part of an ad-hoc battlegroup, and closed to near point blank range with the Emerald Serpent fleet, supported by units of Tragean's force. The battle was a decisive victory for the imperium, crippling most of the Emerald Serpent's vessels and forcing Tragean to abandon Mordecai and retreat to Kendrenec. For the loss of only one capital ship, the Imperium had cleared the way for strikes to take place against the planet itself. The space docks, protected by a powerful space fortress, would also have to be dealt with, but first the missile silos and spaceport on Mordecai Primaris would need neutralising, or any invasion would be massacred.

The missile siloes were pounded for hours by Dreyer's fleet, but the spaceport, protected by energy shields, would need direct attention. The Grey Knights eagerly offered to help, knowing Mordecai was a hotbed of daemonic incursions and blasphemous rituals. Landing outside the space port, the astartes force faced the Emerald Serpent, who had deployed to defend the installation from this expected attack. However, early on in the engagement the Grey Knights destroyed the Emerald Serpent's renegade Knight, which detonated so spectacularly, that it very nearly levelled the space port by itself. Shattered by this turn of events, the Emerald Serpent force withdrew, abandoning the space port and having to watch as Mordecai Primaris' key link to the wider sector was ruthlessly torn apart by the victorious imperial forces. By the time the defenders had rallied a second defensive force, the Grey Knights were gone, leaving behind little more than burning rubble for the chaos lords to reoccupy.

With the offensive going well, Lord Maximus appointed a supreme commander in the Mordecai system, who now set about marshalling his forces for the full scale invasion of the second planet. Using Mordecai Secundus as a jumping off point, the General planned a two stage operation, simultaneously using the Imperial Fleet to knock out the space station and docks, while making a landing in force with mainly Novgorod Guard regiments, although the Imperial Fists, Grey Knights and Sky Lords all made commitments to the system. The war in the Mordecai system was entering a critical phase.