 Various stories centre on the , the elite Praetorian Guard-esque retinue of the Emperor, and the , a classified Imperial organisation of anti-psychic warrior‑nuns originally introduced in Book 4.Most stories are concurrent with the Heresy, with some occurring in the years prior.It includes two stories that take place on Terra, one of which occurs long before the Heresy and adds to the background regarding the Imperial Truth; another entry in the compilation is a Primarch origin story, covering the contentious circumstances under which the gladiatorial Primarch Angron takes command of the , which he renames from the "Warhounds" to the "World Eaters".