Fulgrim – ascended Primarch of the Emperor’s Children – has issued a challenge to his scattered warriors. They must vanquish the Imperial world of Crucible, and bring him the head of the Black Templar charged with its defence. The Phoenician’s plans go far beyond the conquest of a single planet, and what should have been a swift and bloody offensive turns into a gruelling siege. With success uncertain and a world in flames around them, the would-be champions are forced to confront a bitter truth. What must they sacrifice for victory and the favour of their Primarch, and what will be left of them when the war is over?