The Great Rift has torn the Emperor's realm in two. Day by day, war upon war, the galaxy careens ever closer to total annihilation. From amidst the growing anarchy rise those who would seize an ashen victory for themselves. The greatest amongst these is Abaddon the Despoiler. Forging an infernal pact with Vashtorr the Arkifane, he has unleashed the mighty Arks of Omen upon the galaxy – and with them, a new era of war.