Aboard the space hulk Hyberion, where time and causality have been warped by Chaos, Baltus discovered the truth behind the Dark Angels mission! During the Horus Heresy, a rift formed in the ranks of the Dark Angles - and those who turned against the Emperor became known as the Fallen. To seek repentance and prove their loyalty to the Emperor, the true Dark Angels must eliminate their kin. More, there is evidence that one of the Fallen has been orchestrating all of the events in the Calaphrax Cluster to date: the same dark-helmed Space Marine Baltus witnessed after the battle of Exyrion. Meanwhile, on Quintus, Sabbathiel and her crew discovered ancient ruins that point towards the Dark Angels' heretical history - and a battle has erupted between Dark Angels, newly awoken Necrons and Eldar Harlequins! War is here!