Tau expedition suffers defeat in the Rifts but Tanis V cleared once more

03.022M42 began with continued violence in the Hadron Expanse. On Tanis, the Hammers of the Emperor had managed to land a small force to defend the base that the Adeptus Custodes had managed to establish before moving on. The tau however had other ideas and attacked in force. Of particular note was the accurate and punishing firepower of their broadside battlesuits, and within hours of the tau attack beginning the majority of the Hammers of the Emperor were either dead or wounded. However, the tau force was unable to take the base, with the Hammer's commander almost single-handedly turning back the tau attack.

The defence of the base could not be continued with just one unwounded astartes however, no matter how superhuman he may be. Fortunately the adeptus mechanicus were on hand to send in units to reinforce the base on Tanis V, and they prepared for another tau onslaught. Before long it came, this time with even more ferocity and fresh forces. It was clear the tau had the strategic upper hand, and the new force appeared to be from a different group of tau entirely. This was largely academic to the outcome of the battle, as the adeptus mechanicus, surrounded and pummelled by xenos firepower, were unable to hold on to the base. Evacuating the remaining Hammers of the Emperor as they retreated, the Imperium was once again forced to cede Tanis V to the tau, regrouping at their one and only base on the outermost planet of the system.