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.

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? 

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. 

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. 

Ciaphas Cain's latest mission takes him and his Valhallan regiment to the planet of Adumbria to defend against an approaching Chaos invasion. However, infighting with fellow Imperial Guard regiments from the world of Tallarn, commanded by an old 'friend' of Cain's from the Schola Progenium and the uprising of a sinister cult on the planet puts paid to any hopes of an easy life.

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.

In the mysterious city of Queen Mab, the forces of light and darkness are locked in a murderous struggle for truth. The dedicated agents of the Holy Inquisition battle with their shadowy counterparts, the infamous Cognitae, to discover the encrypted identity of the enigmatic, all-powerful King in Yellow. Caught at the heart of this struggle is the pariah Alizebeth Bequin. Bequin must withstand an onslaught of angels, daemons, and even the monstrous warriors of the Traitor Legions, to unpick the greatest riddle of her life. 

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?

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?

In the darkness beyond the galaxy, there are monsters. Some swim closer to the light, drawn by the beacon that is the Astronomican, while others stalk the Void, predators in the dark. The Carcharodons have hunted for millennia, but now they are drawn into a new blackness...the Dark City of the drukhari itself. Commorragh. For a thousand years, Chaplain Tangata Manu has searched for a relic lost under his watch: an ancient thing, once charged into the keeping of the Forgotten One himself. But at the brink of seeing his hunt fulfilled and the relic returned, it is stolen from under him.

Hell-bent on ridding himself of the Fyreslayer rune buried in his chest, Gotrek Gurnisson, the greatest slayer to ever live, travels deep into the strange, alchemical realm of Chamon. Using their mysterious aether-science, the Kharadron overlords of Barak-Urbaz offer an end to Gotrek’s quest. But, as the Bad Moon rises and murderous Gloomspite Gitz threaten to destroy the sky-port, Gotrek pits himself against the most ancient enemy of his people - the greenskins.  

Dark secrets lurk in the Fallen Dome of Periculus, and Tempes Sol of the Guild of Light seeks them out to cement his place in the underhive - if he, and Hive Primus itself, can survive what he unleashes. 

Ahriman, greatest sorcerer of the Thousand Sons and architect of the Rubric that laid his Legion low, continues to walk the path towards salvation, or damnation. Searching for a cure for his Legion, he is forced to consider - was the great ritual somehow flawed from the very beginning? The answer may lie within the mysterious artefact known as the Athenaeum of Kalimakus, a grimoire of forgotten knowledge that is reputed to contain the exact words of the lost Book of Magnus...or, perhaps, even a transcription of the primarch’s deepest and most secret thoughts. 

As the Tyrannic Wars sweep across the face of the Eastern Fringe, Cain and Jurgen find themselves on the jungle moon of a gas giant, fighting off a splinter fleet. The world is uninhabited, but must be protected to prevent the tyranid advance threatening several nearby systems. The situation goes from bad to worse when Cain and the Catachans run into a force of insidious xenos, and the two factions are thrown into a temporary alliance purely to survive.

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.