 Unlike that story, "Betrayer" is presented from the perspective of the rebels, in this case the World Eaters and Word Bearers Legions, and often through the particular viewpoint of Khârn, Captain of the 8th Company of the World Eaters and Equerry to Primarch Angron.In tenuous and fragile cooperation, the two very different Traitor Legions lay waste to worlds across Ultramar; it is a "Shadow Crusade" meticulously planned by Primarch Lorgar of the Word Bearers, who deploys "Abyss"-class spaceships.The campaign's strategic goal is the destruction or isolation of the powerful Ultramarines Legion, its home star system, and the system's considerable resources; removing Ultramar as a factor in the war is one of Horus' primary objectives.