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. 

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.

After a series of victories, the Imperial forces are on the back foot once more. The power of Chaos is rising, the Traitors gain ground, and all hope seems lost. Can Terra endure? 

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.

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. 

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.

In the city of Queen Mab, nothing is quite as it seems. Pariah, spy and Inquisitorial agent Alizebeth Bequin is all of these things and yet none of them. An enigma, even to herself, she is caught between Inquisitors Gregor Eisenhorn and Gideon Ravenor, former allies now enemies who are playing a shadow game against a mysterious and deadly foe. Coveted by the archenemy, pursued by the Inquisition, Bequin becomes embroiled in a dark plot of which she knows not her role or purpose.

Legends abound of the glorious - or infamous - deeds of the emperor's sons. Yet almost nothing is known of Alpharius, the most mysterious of them all, for the lord of the Alpha Legion is unparalleled in the art of obfuscation. Such are his gifts of secrecy and deceit that even his rediscovery has remained an enigma - until now. But when the tale comes from the serpent’s mouth, where do the lies end and the truth begin?

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. 

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.

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.

On Periremunda, the populace are rioting. With local forces unable to contain the widespread civil disorder, Commissar Cain and his regiment of Valhallans are called in to help. However, it seems there is more to the rebellion than first appeared, and Cain suspects sinister forces at work behind the scenes. When the commissar is reunited with Inquisitor Amberley Vail, it seems his fears are realised. In this the fifth book in the popular Ciaphas Cain series, our hero is thrown into a deadly conspiracy that even he might not be able to emerge from alive.

Belisarius Cawl, Archmagos Dominus of the Adeptus Mechanicus, is the most brilliant mind alive. For 10,000 years he has furthered the cause of mankind, working under the aegis of the Emperor and Lord Commander Roboute Guilliman to prevent the inexorable march of the alien and the traitor. Many call him heretic, but all must recognise the magnitude of his achievements, for who else but he was entrusted to create a new generation of Space Marines?  

Born into riches, Probator Symeon Noctis attempts to atone for his past sins by championing the powerless of Nearsteel district. But the sprawling city of Varangantua is uncaring of its masses, and when a bisected corpse is discovered in the neutral zone between Nearsteel and the Adeptus Mechanicus enclave of Steelmound, Noctis finds himself cast into his most dangerous case yet.