The Dark Angels and the Night Lords fought each other to a bloody stalemate during the Thramas Crusade, and although the Lion was ultimately victorious, the event left both Legions scattered and understrength. Far away on Caliban, the Dark Angels loyal to Terra can't wait to get into battle and appoint Astelan as Chapter Master. Meanwhile, Iago Sevatarion, First Captain of the Night Lords, languishes in a prison cell in the heart of Ultramar. Both of them must decide to what extent their personal loyalty extends, and what path they should take in the future.