[Rebellion came as promised, blood flowed as promised, mankind died as promised—whose promise? From the memories of my lord The Emperor, I saw four evil names, and I heard four different laughs. They were filled with malice, they had existed since ancient times, and they were horrors upon the Timeline.]
[They were mankind's cancer.]
[After the Great Rebellion broke out, Horus Lupercal immediately made arrangements with his Legion. They did everything they could to maintain order in the Solar Segmentum, a task that proved extremely difficult with the enemy soon to arrive.]
[Worse news followed one after another, such as the disappearance of The Emperor and Magnus within the Webway, and the accusations the survivors of Prospero brought against the Void Wolves in the Imperial Palace on Terra.]
[Fortunately, mankind's fate had not truly run out. The Lord of Olympia had returned. No one knew the anger in Perturabo, known as iron, and no one dared stand in his way.]
[Even so, by a terrifying force of will, he forcibly pulled himself back into Lucidity from Anger. He discussed countermeasures with Horus, and the two of them cast aside sleep and rest, spending day and night in the Imperial Palace on Terra debating defensive plans.]
[They did many things, such as handling the rebellion on Mars, and strengthening the regions around Terra. Then, a few weeks later, the survivors of Isstvan V sent back a message. Covered in wounds and silent, they stood before the two Primarchs and reported the situation.]
[The present situation was almost enough to make one despair. It was only then that Horus Lupercal learned from the mouths of those venerable heroic souls of the betrayals of the Dark Angels, the White Scars, the Black Dragons, and the Raven Guard.]
[The loyalists had suffered grievous casualties.