The Docks were defended by several companies of Adeptus Sororitas, who had prudently turned the entrance ways into mini fortresses, meaning that any attack would have to blast its way in. The Imperium hoped that the Docks were too unimportant to assault directly, but too valuable to destroy out of hand . So far this had proved true, as the Tau had not attempted to take possession of the Docks nor had they turned the big guns of their fleet upon it.
On 0312.008M42 the attack began, with scouts dropped on the facility followed by swarms of manta-borne crisis suits and skimmers. However access to the Docks would prove difficult as the Sisters of Battle refused to give any ground, and forced a battle in the near vacuum low gravity environment on the surface of the facility. Here the battle was deadly, as any breach in the suits worn by tau and human alike meant certain death. Infantry units found it difficult to maintain their footing and many tau vehicles were destroyed by small arms, the slightest breach causing catastrophic decompression.