From the empyrean's depths, the Ruinous Powers have cast their gaze upon the prosperous world of Califron Primus, a gleaming jewel they have sworn to see shattered. Now, the planet is engulfed in war, but the true heart of the conflict is the colossal Hive City of Angelus.

The massed armies of the Imperium and the relentless hosts of Chaos now converge upon Hive City Angelus, each force bolstered by inscrutable xenos allies who have sided with whichever faction serves their needs. Thus is the stage set for the final grand conflict...