Iron Warriors interfere with Imperial Plans

In late 023M42 the forces of chaos were heavily engaged with the Imperium in the Mordecai system, with the planet of Mordecai Primaris now the site of vigorous imperial military build up. The Iron Warriors, lacking the strategic resources of the Emerald Serpent, nonetheless saw an opportunity to raise their status and frustrate the Imperium's plans, by striking in two places at once. In the Rifts of Hecate against the imperial outpost on Pyhhro Zeta a company of Iron Warriors attacked and defeated the imperial guard garrison, threatening the imperial foothold on the world, while the Imperium were busy dealing with xenos raids.

In the Perseus Deeps a second company of Iron Warriors launched an assault on hanger bays of the Mordecai Docks. Despite the imperial fleet patrolling the area and with no fleet support from chaos naval assets.The traitor astartes managed to achieve surprise and overwhelm the local imperial garrison that had been entrenched on the station. The Mordecai Docks being vast, the Hammers of the Emperor had originally established an imperial foothold then handed this over to naval personnel. The plan had been to build up forces before launching an assault on the rest of the station, which was still holding out and had years of supplies stocked.

The imperial plan was overturned by the Iron Warriors' assault, and even the intervention of the Space Wolves could not hold the chaos forces back. Bitter fighting in the hanger bays resulted in chaos victory, and the Imperium had to abandon their foothold on the installation. Now the options were to try again, lay siege to the docks or gradually obliterate them with the combined firepower of the imperial fleet.