It is the 31st millennium. Under the benevolent leadership of the Immortal Emperor, the Imperium of Man hasstretched out across the galaxy. It is a golden age of discovery and conquest. But now, on the eve of victory, the Emperor leaves the front lines, entrusting the great crusade to his favourite son, Horus. Promoted to Warmaster, can the idealistic Horus carry out the Emperor's grand plan, or will this promotion sow the seeds of heresy amongst his brothers?

After seven years of bitter war, the end has come at last for the conflict known infamously as the Horus Heresy. Terra now lies within the Warmaster’s sights, the Throneworld and the seat of his father’s rule. Horus’ desire is nothing less than the death of the Emperor of Mankind and the utter subjugation of the Imperium. He has become the ascendant vessel of Chaos and amassed a terrible army with which to enact his will and vengeance. But the way to the Throne will be hard as the primarch Rogal Dorn, the Praetorian and protector of Terra, marshals the defences.

Lord of Chemos and bearer of the Palatine Aquila, Fulgrim, primarch of the Emperor’s Children, is determined to take his rightful place in the Great Crusade, whatever the cost. A swordsman without equal, the Phoenician has long studied the art of war and grows impatient to put his skills and those of his loyal followers to a true test. Now, accompanied by only seven of his finest warriors, he seeks to bring a rebellious world into compliance, by any means necessary. 

Long before the coming of the Imperium, the realm of Ultramar was ruled by Roboute Guilliman, the last Battle King of Macragge. Even after learning of his true heritage as a primarch son of the Emperor of Mankind, he strove to expand his domain as efficiently and benevolently as possible, with the XIII Legion Ultramarines as his alone to command.

Baggit is a fast-talking ratling sniper with a greedy eye and loose morals. Clodde is an ogryn, a brute with a core of decency and a desire for a better life. Two abhuman deserters turned thieves, at large in the monolithic city of Varangantua, where only the tough or the ruthless survive. Having landed in debt to a savage crime lord, Baggit and Clodde end up in the crosshairs of the meanest, most puritanical sanctioner in the city.