This is the hook Im running for my next RT campaign. Tell me what you think:
During the Age of Apostasy great warp storms cut off expanses of the imperium from the emperor and others were swollowed whole. One, the cross sector, fought the gathering forces of the warp to their last breath... and even beyond, their spirits clashing against the daemons as the remains of their holy battlefleet was crushed and fused into one of the greatest space hulks ever known to exist: The City of the Dead.
As the warp storms ravaged other areas of the galaxy, the souls of dead men and women cried out, for in the storm, they could not find peace with the emperor. The despair was a beacon to The City and more worlds died, it would arrive to ferry the desperate, living and otherwise, away from the chaos gods.
Years later, after the storms began to subside, The City came into contact with other battlefleets of the imperium, and its speakers, dead yet not, welcomed their brothers and sisters with open arms. The fleets fired upon the hulk, fearing it a creation of the dark powers. The City was mighty, and not even the firepower of the imperium's greatest ships could destroy it, but the wounds it was dealt managed to shear off smaller sections of the hulk that anchored it to realspace, casting it adrift into the warp.
The City of the Dead has not been heard from in the thousands of years it had last appeared, though it still moves throughout the imperium just outside reality, offering to safeguard the souls of the dead that lose their way. Recently the small pieces of the hulk that remain in realspace have gathered in the collection holds of various calixian noble families. Though unknown to most, with the correct knowledge the objects can be used to pull the city back from the warp.
Various powers in the Calixis sector seek its return. Rogue trader dynasties and noble houses seek it for the ancient treasures within it's hull, as well as it's power over death. The forces of chaos seek it for the untold number of souls within, speaking of a great feast that will soon be offered to the dark prince Slaanesh.