After it became obvious that Primarch Horus had betrayed them, the only goal of the few survivors and those who remained faithful to their vow and duty was Terra. The frigate “Eisenstein,” commanded by Captain of the Death Guard Nathaniel Garro, pushes through toward humanity’s cradle to inform the Emperor about a crime committed in the Istvaan system, where hundreds of thousands of the best warriors of Humanity perished as sacrifices to the insatiable gods of Chaos. The flight of the “Eisenstein” will be long and difficult, but even harder will be convincing the rulers of Terra of the impossible—that Horus’s betrayal is real.