"The Yaisdra system had come under siege. The forces of T'au led by Sub-Commander Darkstrider as he is known to the Imperium has brought an insurrection to the system. His lust to expand the T'au Sphere has poured through the system spilling blood and causing strife, all in the name of "The Greater Good".
The futile attempt by an under equipped Imperial Guard has only fed their tide. Colonel Barkan Thade of the 17th Brimlock Dragoons on the besieged planet of Yaisdra IX have held out as long as he could. His forces now lay in shambles, his communication dangerously close to be severed by T'au forces.
Colonel Thade's only hope of survival is the Imperial Navy. Stationed in the Yaisdra sector when Darkstrider invaded, Task Force Solaris is the only Imperial force that can stem the tide of T'au. It's commander Admiral Codleen has his orders to assume a blockade and hold out until reinforcements arrive, but he has another plan entirely.
-Partial Message sent to Terra in request for Adeptus Astartes by Admiral Codleen.