Imperium stave of assaults by Tyranid swarms

By mid 023M42 the Imperium had established a strong base in the Rifts of Hecate and had gained control over the Hecate Gap, save for the rather difficult problem of a greenskin horde occupying much of Haven. However the Imperium retained superiority in space, so for now the convoy routes to Helos Majoris and Ferrosiun were open.

This was just as well, as the tyranid swarm that landed on Helos Majoris at the end of 05.023M42 was not the last. Two more waves of tyranid infestation arrived in 06.023M42 and both were numerous and powerful. The adeptus mechanicus biologis as well as the Ordos Xenos, posited that because admiral Sommerville had been withdrawn to the Hadron Expanse to cover the move of Craddock to the Zadoc subsector, Barham's remaining fleet was unable to cover all lines of advance into the system, and it now looked highly likely that the number of tyranids in the region may have been far higher than first estimated.

The Sisters of Battle were the first to be called on to defend imperial bases, as a swarm of tyranids and bio-artillery appeared in the open area around one of the cities garrisoned by the Imperium on Helos Majoris. The Sisters of battle, their attached stormtroopers and Frateris Militia pushed hard through the city to reach the front lines, with the imperial navy air wings and orbital strikes from Minotaur softening up the waves of enemy creatures. Casualties were high amongst the Sisters as they stubbornly held the main gaits of Helios in the face of the hive fleets largest and most potent xenomorph monsters, but by the second week of 06.023M42 the alien threat had been contained and the city cleared of alien presence.

Only a week later a third wave of tyranids crashed down onto Helos Majoris, further into the wilderness zones of the planet. Unwilling to let the hive mind gather its strength before attacking the main city of Helios again, the Hammers of the Emperor deployed deep into the wilderness away from their supplies, willing to sacrifice their lives to keep the alien threat at bay. In the following battle without support, the Hammers devastated the tyranid menace but at heavy cost in terms of losses. Helos Majoris was declared xenos free on 2306.023M42 but General Maximus was now growing concerned at the strength of the alien forces opposing him in the Rifts.