Mordecai: Astartes launch preparation for invasion of Primaris

By the end of 05.023M42 the Imperium had successfully secured Mordecai Secundus. Immediately thoughts turned to the invasion of Mordecai Primaris, the jewel in the crown of the system and the necessary final struggle for Imperial control over the vital strategic location. With Mordecai Secured, the warp lanes from Bastien to the Zadoc Subsector would be significantly easier to traverse, although there was still a need to open a new passage through the Cicatrix Maledictum.

General Kutuzov wanted an early invasion to prevent the forces of chaos from building up their defences. Astralis could not be assaulted directly, but the defences of Mordecai Primaris would need softening up, as well as the capture or neutralisation of the powerful Mordecai Naval Docks.

The Hammers of the Emperor proposed astartes strikes on both the defences of Mordecai Primaris, most notably the missile silos that would endanger any landing force, and to take out the space docks by launching a space marine led invasion of the facility. That way the docks could not be used, but if successful, they may proove useful to the Imperium instead, speeding up the conquest of the major world around which it orbited.

The Hammers of the Emperor dispatched a company strength force to neutralise the missile silos of Mordecai Primaris, while sending a smaller force to board the Mordecai Docks. Meanwhile General Kutuzov began preparations for the full scale invasion of Mordecai Primaris, liaising between the navy, the Adeptus Mechanicus and imperial guard contingents of the planned assault force.

The Hammers of the Emperor performed multiple bombing runs against the missile silo targets, but quickly realised a land force would be necessary to confirm their destruction. The astartes then performed an assault drop, but found the silos defended by a strong force of World Eaters. A furious battle then developed, with the Hammers of the Emperor making use of their close range firepower while keeping out of range of the berserk fury of the traitor astartes dedicated to Khorne.

It almost worked, but in the end the Hammers had not accounted for a force of Brass Scorpions entering the fray, and these units of the arch enemy held onto key locations long enough to deny the loyalist astartes their objectives. With reinforcements on the way, the Hammers of the Emperor were forced to abandon the mission, and the missile silos remained intact.

At Mordecai Docks the imperial fleet under High Admiral Stark supported the Hammers' boarding parties in case of a reaction by the chaos fleet. None was forthcoming, as the chaos vessels would be outnumbered two to one versus the Imperium, and chose not to engage at such unfavourable odds. The station itself put up heavy fire, but the boarding torpedoes and assault boats weathered the storm of fire and breached the fortress walls in several locations. Vicious close range fighting now took place on the station itself, as traitor astartes from the House of Eschar faction of the Death Guard fought bitterly for every corridor. 

The Hammers of the Emperor took heavy casualties from close range employment of plague sprayers by the Death Guard's Foul Blightspawn, which burnt through the Primaris marines' armour, killing many of them. An intervention from the Death Guard Terminators, teleported from Astralis made things even more difficult for the loyalist astartes, but the Hammers of the Emperor sent in their own elite assault troops and eventually cut through the tainted traitors.

By the end of 05.023M42 around a quarter of the Mordecai Docks had been taken by the Hammers of the Emperor, but at a great cost. They would now need assistance from elsewhere to take the rest of the facility, although for now the docks were no longer able to interfere with the imperial invasion of Mordecai Primaris.