After seven long years of conflict, the Horus Heresy nears its end. But now, as the Warmaster Horus marches on Terra to rip his father from the Throne, the seat of the arch-traitor’s power lies empty. Cthonia, a world once dominated by brutal murder-gangs, is occupied by the Emperor’s praetorians—the indomitable Imperial Fists. For the Sons of Horus, this outrage demands a reckoning.

For Ianthe, war is all too familiar. A former soldier in the Astra Militarum, she now serves Inquisitor Covenant as an agent of the Throne. Her first mission sees her investigating a cult called the Children of Eternity. Falling foul of the local Enforcers, Ianthe soon learns that war in the shadows is seldom straightforward and that the local, angry law-keepers are the least of her troubles.

The Realm of Beasts has ever been a place of savagery and destruction, defiant in the face of Sigmar's feeble attempts at liberation. But now, deep within the mountains of the Ghurish Heartlands, something ancient stirs. A god long-trapped is about to awaken, and the drumbeat of war calls. Ferocious Ironjawz, gluttonous Ogors and towering gargants all set their sights on the human interlopers, determined to cast down their keeps.

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.

The Night Lords were once among the most potent forces of the Imperium, Space Marines who used fear itself as their weapon. Now, cast adrift from the Emperor's light and hunted as heretics after their monstrous betrayal, the Night Lords clad themselves in symbols of death and fight the Long War, bringing pain and terror to all who worship the corpse-god of Terra. A summons from Warmaster Abaddon sends these rebels on a dangerous journey that leads inexorably to a conflict with the Emperor's chosen warriors, the Blood Angels.

On the 13th day of Secundus, the bombardment of Terra began. With the solar defences overcome through the devastating strength of the Traitor armada and the power of the warp, Horus launches his assault on the Throneworld in earnest. After withstanding a ferocious barrage of ordnance, an immense ground war commences outside the Palace, with every inch gained paid for in the lives of billions.

On the prison world of Zartak, darkness has fallen on arbitrators and inmates alike. The Night Lords have come, bringing with them the shadow of fear and pain. But these monsters are not the only ones with an interest in Zartak. From the void, running on silent, another fleet emerges. These Space Marine warriors are grey-clad and white-faced, and their eyes are as black as the Outer Dark – the savage Carcharodon Astra.

He is known by many names - Clonelord, Manflayer, Primogenitor. He is the epitome of deceit and perversion, and feared by man and monster alike. Once the Chief Apothecary of the Emperor's Children, the madman known as Fabius Bile possesses a knowledge of genetic manipulation second to none.

Belisarius Cawl, Archmagos Dominus of the Adeptus Mechanicus, is the most brilliant mind alive. For 10,000 years he has furthered the cause of mankind, working under the aegis of the Emperor and Lord Commander Roboute Guilliman to prevent the inexorable march of the alien and the traitor. Many call him heretic, but all must recognise the magnitude of his achievements, for who else but he was entrusted to create a new generation of Space Marines?

The primarchs, nigh-immortal sons of the Emperor of Mankind, take the stage in a series of short stories showcasing some of their great deeds and hideous acts from across the Great Crusade and the Horus Heresy.