As the flames of treachery spread throughout the Imperium, Horus plots to subvert or destroy all those who would stand against him. On Mars, home world of the Mechanicum priesthood, the great manufactory-cities have long produced much of the weaponry required for the expeditionary fleets across the galaxy - making the world invaluable to whoever controls it in the coming war.

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.

On an Imperial outpost world on the fringes of tau space, the renowned Commissar Ciaphas Cain and his fractious regiment of Valhallan Guard, newly created from the remnants of two devastated units, find themselves in the middle of a war. As the Astra Militarum struggle to contain worldwide civil insurrection, can the wily Commissar Cain identify the real villain before the planet is lost to the Imperium forever?

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 Custodian Guard have stood watch over the Emperor's Palace on Terra since the foundation of the Imperium. Charged with protecting the Master of Mankind from all threats, within and without, their fearsome resolve is renowned throughout the galaxy, and their golden armour is the last thing that a would-be assassin or saboteur will ever see.

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.

Two centuries ago, the Imperium of Man and the upstart Tau Empire fought to a standstill in the Damocles Gulf. Now, as the 41st millennium draws to a close, the tau have returned. As the world of Agrellan falls under attack, the White Scars and Raven Guard rush to its defence, but with the skilled Commander Shadowsun leading the alien forces, the Space Marines and their allies are hard pressed.

Kept alive and imprisoned for 10 thousand years, Luther is the curse and the salvation of the Dark Angels made manifest. None are so close to the heart and history of the Chapter as the man that embodies all that was great about the First Legion and all that is shameful about the Dark Angels. In his story is writ the tale of the Horus Heresy and the fall from Enlightenment in a single long life. Glory, honour, pride, shame and betrayal weave a tapestry of truth and lies that the Supreme Grand Masters of the Dark Angels have sought to understand and unbind across 10 bloody millennia. 

Under almost constant besiegement by the hosts pouring from the Eye of Terror, Cadia acts as a bulwark against tyranny and death. Its fortresses and armies have held back the hordes of Chaos for centuries, but that grim defiance is about to reach its end. As Abaddon's Thirteenth Black Crusade batters Cadia's defences, and armies of the Imperium flock to reinforce this crucial world, a terrible ritual long in the making comes to fruition and the delicate balance of this brutal war shifts.

War rages in the Caradryad Sector. Worlds are falling to madness and rebellion, and the great war machine of the Imperium is moving to counter the threat. Amongst its agents is Inquisitor Covenant. Puritan, psyker, expert swordsman, he reserves an especial hatred for those of his order who would seek to harness the power of Ruin as a weapon. Summoned to an inquisitorial conclave, Covenant believes he has uncovered such a misguided agent and prepares to denounce the heretic Talicto before his fellows.

The shrine world of Divinatus Prime has become lost to the light of the Astronomican, and no ship can piece its veil. Only the Lord of Death himself, Blood Angels Chief Librarian Mephiston, has any hope of discerning the fate of this once pious world. After enacting a powerful blood ritual, Mephiston and an honour guard of his fellow Blood Angels reach the stricken shrine world to find it seized by religious civil war. Each faction fights for dominance of a potent artefact, the Blade Petrific, said to be wrought by the Emperor Himself.  

The Blood Angels Chapter of Space Marines is under threat. Having obliterated all human life in the Red Scar region of space, the largest tendril of Hivefleet Leviathan ever seen in the Imperium has converged and is making relentlessly for Baal. To face this awesome foe, Commander Dante has called upon the Successor Chapters of the ancient Ninth Legion. The Sons of Sanguinius gather in numbers not seen since the dark days of the Horus Heresy. 

Holy warbringer of the Legio Metalica, the Imperator Titan Casus Belli has routed armies and levelled cities over 10,000 years of service in the name of the Machine God. As war engulfs the Dark Imperium, this mechanical god of battle arrives to destroy the renegade armies and tech-priests of Nicomedua. At the head of a battlegroup of Titans, Imperial Knights and skitarii, Casus Belli must defeat tainted war engines, Traitor Legionnares and armies of cultists.

Of all the Emperor’s sons who fell to Chaos, it is perhaps Magnus the Red whose tale is the most tragic. Sanctioned because of his desire for knowledge, chastised, judged, and shattered to his very elements – there is much for the Crimson King to feel vengeful for. Yet revenge is not the only thing that draws him to Terra alongside the Warmaster’s besieging armies. He seeks something, a fragment, the missing piece of himself that lies within the most impregnable place on the planet – the inner sanctum of the Imperial Palace.

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.