On the Forge World of Urdesh, the combined forces of the Imperial Crusade engage in a final, bloody battle with the Arch-Enemy's Commander-in-Chief known as the Anarch and his elite warriors, the barbarian Sons of Sek. Victory for either side would decide not only the fate of Urdesh... it would determine the outcome of the entire Sabbat Worlds Crusade. Ibram Gaunt - now serving as Warmaster Macaroth's right-hand man - found himself at the very center of the struggle. His regiment, the Tanith First Ghosts, holds the vital key to ultimate success. But as the forces of the Imperium and Chaos prepare for a final large-scale confrontation, Gaunt discovers that the greatest threat may come from within rather than without.