It is the 32nd millennium, and the Imperium is at peace. The Traitor Legions of Chaos are but a distant memory, and the many alien races that have long plagued mankind are held in check by the Space Marines. When a mission to exterminate one such xenos breed on the world of Ardamantua draws in more of their forces, the Imperial Fists abandon the walls of Terra for the first time in more than a thousand years.

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.

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 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.

Cadia licks its wounds in the wake of the Thirteenth Black Crusade. The heretic forces retreat on all fronts. The day is won. But Lord Castellan Creed cannot rest easy. Something tells him the assault was a mere prelude to something greater, something more final. He is right. Out of the Eye of Terror comes Abaddon the Despoiler, at the head of a warhost unmatched in scale since the dread days of the Horus Heresy.

Faced with an ork invasion of Piscina IV, the 3rd Company of the Dark Angels believes the threat to be minimal. As enemy numbers continue to increase, their commander, Captain Belial, insists that his Company are strong enough to resist. But Scout-Sergeant Naaman knows just how dangerous this foe can be, and when a renewed offensive takes the Dark Angels by surprise, the orks swarm towards Kadillus Harbour.

Ufthak Blackhawk and the green tide descend upon Hephaesto - an Adeptus Mechanicus forge world bristling with loot - only to find it already under siege by the notorious Freebooter Kaptin Badrukk. When his warboss, Da Biggest Big Mek, orders temporary co-operation, Ufthak seeks to make a name for himself by crushing some of the Imperium’s most advanced defenders and claiming the greatest prize. 

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. 

On the grim death world of Fenris, the Space Wolves Chapter selects its aspirants from the best and brightest of the young tribesmen. Ragnar of the Thunderfist tribe finds his life changed forever when he is chosen. After being revived from a savage death on the battlefield, Ragnar is recruited into the fearsome Space Wolves Chapter. He is then thrown into a galactic war against the dark forces of Chaos. However, the implanting of the Canis Helix unleashes his primal instincts and Ragnar must fight to control the beast within him.

A great darkness has befallen the galaxy, and the armies of Chaos are rampant. To survive, humanity must retaliate and take back what they have lost. By the will of the reborn primarch, Roboute Guilliman, is the Indomitus Crusade launched - a military undertaking that eclipses all others in known history. From the Throneworld of Terra does the Avenging Son hurl his fleets, their mission the very salvation of mankind.