In the darkness of Imperium Nihilus, across half a million worlds cut off from the dim light of Holy Terra, a beacon is lit. The Red Angel returns to an unsteady galaxy and his scattered sons heed the call to slaughter. Aboard the World Eaters' flagship, Kossolax the Foresworn, self-appointed lord regent of the XII, fights to keep the old dreams of the Legion alive, but finds the return of his hated father both an opportunity and a threat to the warriors' fragile unity.

Marooned on a worthless moon with a rag-tag band of traitors as despicable as himself, Ortan Leidis of the Angels of the Grail dares to dream of something greater.

Half a galaxy away, Graucis Telomane of the Grey Knights has been readying himself for this day, and plans six centuries in the making are finally set in motion - plans that will see the eradication of the Emperor's greatest mistake once and for all...