Their presence discovered Tyranid bioforms matching the genotype of Hive Fleet Nemesis boiled out to defend their beachhead and swamped the mechanised column before it could react. The Dark Angel's suffered heavy casualties in the opening moments of the conflict and although they fought bravely and great tenacity they couldn't hope to overcome the hordes of ravening aliens. Only when all hope of victory was gone did Captain El'Zahariel, himself wounded in the fighting, order a retreat back to the drop ships.
The Tyranid canker would have to be left to fester and grow for the time being but their presence was at least discovered. The Dark Angel's issued a summons for all Space Marine chapters in the area to provide aid and demanded Imperial High Command commit the Imperial Guard to the defence of New Cerberex should the infestation not be quashed in its infancy. But with the Imperium already dangerously overstretched and Inquisitor Vorushko stridently demanding forces to prosecute the Librian Heretics it was doubtful significant forces would be mustered. El'Zahariels rallying call would not go completely unanswered however; a Salamander's strike cruiser was in the region and promised to re-enforce the Dark Angels with all haste.
At almost the same time the Blood Angels were investigating the silence of the small but important Corredon outpost. Nothing had been heard from the base for several weeks, and it was widely expected that the station had fallen to Xenos. The question was, which one? The force of Blood Angels landed on the rocky outpost on 1702.014M42 and could find little trace of an invasion. Instead they found a charnel house, the former inhabitants of the outpost slaughtered and dismembered. THen the invaders attacked.
The Blood Angels defended bravely, but were outclassed by their enemy. The astartes died buying enough time to get a message back to their strike cruiser that the tyranids had overrun the base. Few marines made it back to their warship, and as soon as they did the Blood Angels vessel broke orbit and raced to the jump point as fast as possible. On the edge of the system something lurked, something large and menacing, its psychic presence overwhelming the astartes astropath. The shadow of the warp was closing in around New Cerberex.