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.

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.

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.

Inquisitor Erasmus Crowl has discovered a terrible plot, its roots firmly planted in the very highest levels of Terra. Pursuing it is fraught with risk, but Crowl’s sense of duty compels him to persevere. He and his acolyte Spinoza run down their leads in secret, knowing that their every move invites danger, but even as they begin to reveal the truth, a greater peril is unfolding in the skies - the Great Rift is becoming manifest. During the madness that threatens to tear Terra asunder, Crowl’s Inquisitorial base of operations comes under attack and is badly ravaged.

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. 

As the Indomitus Crusade begins, fleets of mighty warships leave Terra on a vital quest to stabilise Imperium Sanctus in the wake of the Great Rift. The returned primarch, Roboute Guilliman, leads a huge force towards the shrine world of Gathalamor, where stable warp routes will allow the flotilla to spread across the beleaguered southern half of the Imperium.

The Indomitus Crusade continues its war across the stars. The primarch Roboute Guilliman has finally broken through the orkish threat bedevilling the sectors near Fenris, and makes ready to push on his bid to stabilise the Imperium Sanctus—but old and bitter foes stand in his way. Kor Phaeron, the Dark Cardinal, threatens the previously stable core of the Segmentum Solar. Waves of rebellion instigated by his infiltrating priests suggest an imminent, large-scale invasion by the Word Bearers Legion. 

In the void and upon the worlds of Greater Ultramar, the battle for the Imperium continues. Intent on rebuilding his home realm and using it as a base to reconstruct the ravaged stellar empire of mankind, the returned primarch, Roboute Guilliman, proceeds with his war to drive Mortarion and his Death Guard Traitor Legion from the domain of the Ultramarines. But when Guilliman brings his brother to battle upon the diseased plains of Parmenio, the intervention of a greater power in their fraternal struggle threatens to upend the Imperial Regent’s understanding of the galaxy. 

The Indomitus Crusade has brought the Emperor's vengeance to thousands of star systems. The fleets and armies under the leadership of Roboute Guilliman fight for the survival of humanity against the forces of the Chaos Gods. But the traitors and heretics are not the only foe looking to destroy the rule of Terra. Xenos prey on human worlds in numbers not seen for millennia. Worst amongst them are the rampaging orks, whose migration conquests threaten to reverse the many gains of Fleet Primus. 

The paths of Roboute Guilliman and his fallen brother Mortarion bring them inexorably together on Iax. Once a jewel of the Imperium, the garden world is dying as the plans of the Lord of Death to use it as a fulcrum to drag the stellar realm of Ultramar into the warp come to deadly fruition. While Guilliman attempts to prevent the destruction of his kingdom, Mortarion schemes to bring his brother low with the Godblight, a disease created in the Cauldron of Nurgle itself, made with the power to destroy a son of the Emperor. 

Pursued by vengeful eldar, Magos Kotov’s Explorator armada heads into a newly revealed area of space in pursuit of ancient secrets. As the Adeptus Mechanicus forces and Black Templars Space Marines tackle the twin threats of the wrathful aliens and insurrection aboard the fleet, a greater danger reveals itself.

Fell times have come to the galaxy. Cadia has fallen, destroyed by the onslaught of Chaos. A Great Rift in the warp has opened, and from its depths spew daemons and the horrors of Old Night. But all hope is not lost… A hero, long absent, has returned, and with him comes the wrath of the Ultramarines reborn. Roboute Guilliman has arisen to lead the Imperium out of darkness on a crusade the likes of which has not been seen since the fabled days of the Emperor. But never before have the forces of Ruin amassed in such numbers, and nowhere is safe from despoliation. 

The Officio Assassinorum safeguards the future of humanity. Its agents are the bloody-handed, secret saviours of the Imperium, killers charged with achieving the impossible...and Vindicare assassin Absolom Raithe has just been handed the most difficult assignment of his career.

Legend tells of a foolhardy expedition, led by the radical Magos Telok, that ventured out into the unknown space beyond the Halo Worlds in search of the 'Breath of the Gods' - an arcane device with the power to unmake and reshape the very stars themselves. Thousands of years later, the ambitious Lexell Kotov musters his Adeptus Mechanicus Explorator fleet and sets out to follow in mad old Telok's footsteps. 

Before the being called the Emperor revealed himself, before the rise of the aeldari, before the necrontyr traded their flesh for immortal metal, the world was born in violence. Even when they inhabited bodies of flesh, Trazyn the Infinite and Orikan the Diviner were polar opposites. Trazyn, a collector of historical oddities, presides over a gallery full of the most dangerous artefacts - and people - of the galactic past. Orikan, a chronomancer without peer, draws zodiacs that predict and manipulate the future.