When the vital forge world of Orestes comes under attack by a legion of Chaos Titans, the planet is forced to appeal for help. The Titans of Legio Invicta, although fresh from combat and in desperate need of refit and repair, respond, committing their own force of war engines to the battle. As the god-machines stride to war, the world trembles, for the devastation they unleash could destroy the very world they have pledged to save.

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. 

On the war-torn world of Croatoas, the armies of the Astra Militarum do battle with the twisted servants of the Ruinous Powers. Against the backdrop of this increasingly desperate conflict, tanker Hadeya Etsul finds herself consolidated into a Cadian regiment, and placed in command of the Leman Russ Demolisher Steel Tread. Haunted by nightmares, surrounded by a dysfunctional crew and striving to find her place amidst a proud and insular regiment with a culture so different from her own, Etsul must guide her crew to victory. 

On the forge world of Morod, the machines never stop and the work never ends. The population toils in the mines and factoria to protect humanity from the monsters in the void, while the Adeptus Mechanicus enjoy lives of palatial comfort. Genetor Gammat Triskellian seeks to end this stagnant corruption. When he learns of a twisted congregation operating within the shadows, one which believes that the tech-priests are keeping people from their true salvation, he sees in them an opportunity to bring down Morod's masters and reclaim the world in the name of progress.

Valorous Heart. Our Martyred Lady. Bloody Rose. These names of Adepta Sororitas orders are famed across the galaxy, as are the Battle Sisters who serve the emperor's will. To die in the name of the God-Emperor of Mankind is to live eternal, and none are more willing to bleed in his name than the Adepta Sororitas - the Sisters of Battle. The Book of Martyrs charts the deaths of these exemplars.

After seven long years of conflict, the Horus Heresy nears its end. But now, as the Warmaster Horus marches on Terra to rip his father from the Throne, the seat of the arch-traitor’s power lies empty. Cthonia, a world once dominated by brutal murder-gangs, is occupied by the Emperor’s praetorians—the indomitable Imperial Fists. For the Sons of Horus, this outrage demands a reckoning. 

War rages in the Caradryad Sector. Worlds are falling to madness and rebellion, and the great war machine of the Imperium is moving to counter the threat. Amongst its agents is Inquisitor Covenant. Puritan, psyker, expert swordsman, he reserves an especial hatred for those of his order who would seek to harness the power of Ruin as a weapon. Summoned to an inquisitorial conclave, Covenant believes he has uncovered such a misguided agent and prepares to denounce the heretic Talicto before his fellows.

The skitarii are the soldiers of the Machine God, the tireless legions of the Adeptus Mechanicus. Holy warriors, they carry the word of the Omnissiah across the galaxy, destroying impure machines and spearheading the Quest for Knowledge. A discovery of ancient technology sends a skitarii legion into battle on a forge world overrun by Chaos. When a cataclysm cuts him off from his tech-priest overseers, Stroika must rally his forces and battle both corrupt machines and Chaos Space Marines.

Phil Kelly continues his look at the life of Commander Farsight with his first campaign against the full might of the Imperium and shows how the T'au Empire's technological superiority fares against Imperial grit.

Exile to the miserable world of Sedh, the disgraced Necron Lord Oltyx is consumed with bitterness. Once heir to the throne of a dynasty, he now commands nothing but a dwindling garrison of warriors, in a never-ending struggle against Ork invaders. Oltyx can think of nothing but the prospect of vengeance against his betrayers, and the reclamation of his birthright. But the Orks are merely the harbingers of a truly unstoppable force. Unless Oltyx acts to save his dynasty, revenge will win him only ashes. 

On the capital world of Potence, young enforcer cadet Rudgard Howe is caught up in a bitter internecine feud to inherit his father's position of chief enforcer. As the tithe fleets approach, he is sent on his first mission to ensure that the planet's distant agri-facilities fulfil their quotas to the god-emperor. Farmed with serfs and managed by ex-Militarum soldiers, the agri-facilities are places of shocking brutality and hopelessness. 

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. 

Lord Azariel, Head of the Navigator House Brobantis is dead. His widow and murderer, the Lady Chettamandey, stands to inherit his power and influence. Her plans for ascension are curtailed when she’s drawn into a dark world of ritual killings and cult murders. With planets being dragged into the warp seemingly at a whim, the threat to Chettamandey’s legacy is dire, and only she can avert potential disaster.   

Long before the coming of the Imperium, the realm of Ultramar was ruled by Roboute Guilliman, the last Battle King of Macragge. Even after learning of his true heritage as a primarch son of the Emperor of Mankind, he strove to expand his domain as efficiently and benevolently as possible, with the XIII Legion Ultramarines as his alone to command.

The Blood Angels Chapter of Space Marines is under threat. Having obliterated all human life in the Red Scar region of space, the largest tendril of Hivefleet Leviathan ever seen in the Imperium has converged and is making relentlessly for Baal. To face this awesome foe, Commander Dante has called upon the Successor Chapters of the ancient Ninth Legion. The Sons of Sanguinius gather in numbers not seen since the dark days of the Horus Heresy.