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?

Constantin Valdor. It is a name that brings forth images of heroism, honour and peerless duty. For it is he who commands the will of the Legio Custodes that most esteemed and dedicated cadre of elite warriors. He is the Emperor’s sword, His shield, His banner and he knows no equal. Clad in shining auramite, his fist clenched around the haft of his Guardian Spear, he is the bulwark against all enemies of the throne, within or without. Nearing the end of the wars of Unity, Valdor’s courage and purpose is put to the test as never before. 

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.

The war for the fate of mankind blazes on. Though the outer defences have fallen, the walls of the Palace itself remain inviolate as Rogal Dorn, the Praetorian of Terra himself, uses every known stratagem and ploy to keep Horus' vast armies at bay. In Perturabo, the Traitor siegebreaker, Dorn faces an adversary worthy of his skill. A terrible, grinding attrition ensues. The crucial battle for the Lion's Gate spaceport is at the heart of this conflict. With it in their possession, the Traitors can land their most devastating weapons on Terran soil. Dorn knows it must not fall.

In the Pandorax System, on the death world of Pythos, an ancient secret that has laid buried for millennia has been unearthed.... Ignorant of this terror, troopers of the Catachan 183rd, stranded on Pythos and under the command of Colonel 'Death' Strike, find themselves under attack by the forces of Chaos. Daemons in their thousands flock the sky, and none other than Warmaster Abaddon leads the attack.

When the world of Armageddon is attacked by orks, the Black Templars Space Marine Chapter are amongst those sent to liberate it. Chaplain Grimaldus and a band of Black Templars are charged with the defence of Hive Helsreach from the xenos invaders in one of the many battle zones. But as the orks' numbers grow and the Space Marines' numbers dwindle, Grimaldus faces a desperate last stand in an Imperial temple.

The scattered worlds of the Elara's Veil nebula were once protected by the oath of unity sworn by three mighty Chapters of the Adeptus Astartes. The Star Scorpions were undone by flaws in their genetic coding. The Celestial Lions were ravaged by the Inquisition for sins they did not commit. Now, after hundreds of years, only the Emperor's Spears still keep their vigil. They are barbarian watchmen against the Outer Dark, bloodied but unbroken in their long duty.   

In the hellish sprawl of Imperial Terra, Ordo Hereticus Inquisitor Erasmus Crowl serves as a stalwart protector, for even the Throneworld is not immune to the predations of its enemies. In the course of his duty, Crowl becomes embroiled in a dark conspiracy, one that leads all the way to the halls of the Imperial Palace. As he plunges deeper into the shadowy underbelly of the many palace districts, his investigation attracts the attention of hidden forces, and soon he and his acolyte Spinoza are being hunted.

The Cadian Gate is broken, and the Imperium is riven in two. The might of the Traitor Legions, kept shackled for millennia behind walls of iron and sorcery, has been unleashed on a darkening galaxy. Among those seeking vengeance on the Corpse Emperor’s faltering realm are the Death Guard, once proud crusaders of the Legiones Astartes, now debased creatures of terror and contagion. 

When Horus fell, his Sons fell with him. A broken Legion, beset by rivalries and hunted by their erstwhile allies, the former Luna Wolves have scattered across the tortured realm of the Eye of Terror. And of Abaddon, greatest of the Warmaster's followers, nothing has been heard for many years. Until now....