Catechism of Hate is a limited release novella by Black Library, and the eighth novel in the Space Marine Battles Series. It was written by Gav Thorpe and published in January 2012.
Among the hallowed ranks of the Adeptus Astartes, few have attained such renown as Ortan Cassius – Ultramarines Chaplain and Master of Sanctity. Hero of the First Tyrannic War, his name is legend. When the hive fleets target the world of Styxia, Cassius leads the defence, marshalling the Ultramarines against the xenos monstrosities.