Since the earliest days of the Great Crusade, Sanguinius - angelic primarch of the IXth Legion - was ever among the closest and most loyal of Horus' brothers. But the Blood Angels have long kept their true nature hidden from the rest of the Imperium, and when the Warmaster hints that the key to their salvation may lie in the ruins of a conquered world, the sons of Sanguinius race to claim it.

Unaware of the wider Heresy and following the Warmaster's increasingly cryptic orders, Roboute Guilliman returns to Ultramar to muster his Legion for war against the orks massing in the Veridian system. Without warning, their supposed allies in the Word Bearers Legion launch a devastating invasion of Calth, scattering the Ultramarines fleet and slaughtering all who stand in their way. This confirms the worst scenario Guilliman can imagine - Lorgar means to settle their bitter rivalry once and for all.

From the battlefields of Phall and Isstvan, to the haunted shadows of Terra itself - the greatest war in the history of mankind rages on. While the traitor Legions continue their campaign of terror across the galaxy, preparations are made for the defence of the Imperial Palace and the final, inevitable reckoning that must yet come between Horus and the Emperor....

As the Horus Heresy divides the Imperium, Corax and his few remaining Raven Guard escape the massacre at Isstvan V. Tending to their wounds, the bloodied Space Marines endeavour to replenish their numbers and return to the fray, taking the fight to the traitor Warmaster.

Perturabo - master of siegecraft and the executioner of Olympia. Long has he lived in the shadow of his more favoured primarch brothers, frustrated by the mundane and ignominious duties which regularly fall to his Legion. When Fulgrim offers him the chance to lead an expedition in search of ancient and destructive xenos weaponry, the Iron Warriors and the Emperor's Children unite and venture deep into the heart of the great star maelstrom that haunts Perturabo's dreams.

The galaxy is burning. The Emperor's loyal primarchs prepare to do battle with Warmaster Horus and his turncoat Legions on the black sand of Isstvan. Such dark times herald new and yet more terrible things still to come, and when Astropath Kai Zulane unwittingly learns a secret that threatens to tip the balance of the war, he is forced to flee for his life. Alongside a mysterious band of renegades, he plunges into the deadly underworld of Terra itself, hunted like a criminal by those he once trusted.

After the betrayal at Isstvan, Horus begins his campaign against the Emperor, a galaxy-wide war that can lead only to Terra. But the road to the final confrontation between father and son is a long one - seven years filled with secrecy and silence, plans and foundations being formed across distant stars. An unknown history is about to be unveiled as light is shed on the darkest years of the Horus Heresy, and revelations will surface that will shake the Imperium to its very foundation....

In the wake of the Dropsite Massacre at Isstvan V, the survivors of the Salamanders Legion searched long and hard for their fallen primarch, but to no avail. Little did they know that while Vulkan might have wished himself dead, he lives still...languishing in a hidden cell for the entertainment of a cruel gaoler, his brother Konrad Curze.

The Emperor is enraged. Primarch Magnus the Red of the Thousand Sons Legion has made a terrible mistake that endangers the very safety of Terra. With no other choice, the Emperor charges Leman Russ, Primarch of the Space Wolves, with the apprehension of his brother from the Thousand Sons home world of Prospero.

The Heresy came to Calth without warning. In just a few hours of betrayal and bloodshed, the proud warriors of the XIIIth Legion - Guilliman's own Ultramarines - were laid low by the treachery of their erstwhile brothers of the XVIIth. Now, as the planet is scoured by solar flares from the wounded Veridian star, the survivors must take the fight to the remaining Word Bearers and their foul allies, or face damnation in the gloomy arcology shelters beneath the planet's surface.

Amidst the galaxy-wide war of the Great Crusade, the Emperor castigates the Word Bearers for their worship. Distraught at this judgement, Lorgar and his Legion seek another path while devastating world after world, venting their fury and fervour on the battlefield. Their search for a new purpose leads them to the edge of the material universe, where they meet ancient forces far more powerful than they could have imagined.

Once the brightest star in the Imperium and always first among his primarch brothers, Horus has dragged the Space Marine Legions into the bloodiest conflict that the galaxy has ever seen. While their allies wage war on a thousand different fronts, the XVIth Legion descend upon the Knight world of Molech - home to the ruling House Devine, and a principle stronghold of the Imperial Army.

After the horrors of Istvaan V, Horus declares outright war against the Imperium. In the shadows of the Emperor's Palace, powerful figures convene. Their plan is to send a team of assassins to execute the arch-traitor Horus and end the war for the galaxy of mankind before it's even begun. But what they cannot know is that another assassin is abroad already, with his sights firmly set on killing the Emperor.

When Horus the Warmaster rebelled against the Emperor, the ensuing civil war nearly destroyed the Imperium. War raged across galaxy, pitting Astartes against their battle-brothers in a struggle where death was the only victor. But long before that, the Legions struggled with their identities and the demands of the Great Crusade. From battles with alien invaders to conflicts within a Legion, and even dealing with a wayward primarch, these stories show the battles fought as the Great Crusade draws to a close and the Horus Heresy begins....

Censured at the Council of Nikaea for his flagrant use of sorcery, Magnus the Red and his Thousand Sons Legion retreat to their homeworld of Prospero to continue their use of the arcane arts in secret. But when the ill-fated primarch forsees the treachery of Warmaster Horus and warns the Emperor with the very powers he was forbidden to use, the Master of Mankind dispatches fellow primarch Leman Russ to attack Prospero itself.