The end of 09.018M42 heralded a resurgence in Crusade activity in the Foramen Interdictum. Cybixx, now de facto leader of the Crusade outside the Hadron Expanse, had already initiated raids on chaos (for his own benefit), and the Grey Knights and Dark Angels had begun the pacification of the Destino system, which had already resulted in the clash with fellow astartes.
Now the Dark Angels and Grey Knights, satisfied that the foothold had been secured in the Destino system, moved into the Foramen Majoris and lent their aid to the loyalist cause against the forces of chaos. Here in the Majoris, the Crusade had little in the way of differences to fight over, except over Hathek's dubious policy of allowing daemon exposed Guard units to remain intact. At Tarlius, although on the same side as the loyalists, even the Imperial Fists gave the newly arriving Crusade strike cruisers a cold welcome following the clash at Destino.
Unsupported but confident, the Grey Knights and Dark Angels conducted a two pronged assault on the defenders of Tarlius III (Darnath's Folly), with the Grey Knights assaulting the Iron Warriors forces, and the Dark Angels launching a bloody attack against the Wraiths of Prospero - a thousand sons force allied to the Emerald Serpent. On Tarlius II, the main Iron Warrior strength was being held in a defensive posture, so the forces encountered on the outer planet were not of the same caliber. Nevertheless the Grey Knights found the going tough against the forces of chaos, but after a protracted battle all their objectives were secure.
The Dark Angels similarly took all their key objectives in the first 24 hours, a move which meant coordinated defence of the bases on the world would now be impossible for the Iron Warriors and their allies. The fighting continued for a few more days, before the Iron Warriors withdrew to defensive positions around the main settlement. The Crusade had established a secure bridgehead for the Imperium on Tarlius III, aiding its reconquest.