During the turbulent Reign of Blood, a great schism in the Imperial Ecclesiarchy threatened all of Terra and promised a darkness to rival the terrors of Old Night. Fell times have come again to the Imperium, and a War of Faith appears inevitable. Standing in the way of catastrophe is Celestine, the Living Saint and one of the greatest heroes of the age. Only she can reunite the warring factions of the Ecclesiarchy and prevent a second Reign of Blood.

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.

In the grim nightmare future of the 41st millennium, the witch-hunting zealots of the the Sisters of Battle stand between humanity and damnation. From the elite Seraphim warriors to the berserk Sisters Repentia, they are the strong arm of the Ecclesiarchy and the brutal hammer of witches. When dangerous psychic heretic Torris Vaun escapes from her custody, Seraphim Miriya is disgraced in the eyes of her fellow sisters and superiors. Following Vaun's trail to the planet Neva, Miriya takes her sisters in pursuit and, along with Hospitalier Sister Verity, starts her investigations.

Opal is a gleaming shrine world of saints and soldiers, beloved of the Emperor Himself. Sent to retrieve the skull of the revered Saint Veres, Sister Superior Augusta of the Order of the Bloody Rose and her squad find themselves in the midst of the capital’s holiest festival, a time of reverence and celebration. But all is not well – despite what its planetary leaders would have Augusta believe, political danger bubbles under the surface, and rebel attacks gnaw away at the city’s outskirts. The greatest threat, however, is yet to come.

For Ianthe, war is all too familiar. A former soldier in the Astra Militarum, she now serves Inquisitor Covenant as an agent of the Throne. Her first mission sees her investigating a cult called the Children of Eternity. Falling foul of the local Enforcers, Ianthe soon learns that war in the shadows is seldom straightforward and that the local, angry law-keepers are the least of her troubles.

With the birth of the Cicatrix Maledictum the Imperium of Mankind suffers as never before. Conflict and corruption is rife on every front and precious little hope remains, save for those who hold to their faith when faced with destruction.... Denied a martyr’s death during the battle for Ophelia VII, Sister Evangeline of the Order of Our Martyred Lady is blessed with a new and grave duty: to embark on a pilgrimage beyond the Great Rift to recover a precious and powerful artefact - the Shield of Saint Katherine.

Throughout the tortured galaxy, Ephrael Stern is known by many names. The Thrice-born. The Daemonifuge. The Heretic Saint. Trapped deep within Imperium Nihilus following the coming of the Great Rift, the maligned Sister of Battle fears the Imperium is no more. The God-Emperor’s light, which has guided her through centuries of strife, has too extinguished. Seemingly forsaken, Stern is bereft until a mysterious stranger arrives, offering her a new destiny. One that might yet see the Imperium saved. Stern must prove herself worthy of the God-Emperor’s grace once more.

The Realm of Beasts has ever been a place of savagery and destruction, defiant in the face of Sigmar's feeble attempts at liberation. But now, deep within the mountains of the Ghurish Heartlands, something ancient stirs. A god long-trapped is about to awaken, and the drumbeat of war calls. Ferocious Ironjawz, gluttonous Ogors and towering gargants all set their sights on the human interlopers, determined to cast down their keeps.

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?

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.

Sister Adamanthea is an oddity among the Adepta Sororitas - a Sister Repentia who has been cleansed of her sin and returned to her duty, rather than finding penance in death. Seen by the faithful as a living miracle, she herself is unsure. Still feeling the weight of her crime, she wonders if she belongs in the sisterhood at all. When she is forced to appear with a famed priest on a most holy day, Adamanthea's doubts itensify...until disaster strikes.

Cadia licks its wounds in the wake of the Thirteenth Black Crusade. The heretic forces retreat on all fronts. The day is won. But Lord Castellan Creed cannot rest easy. Something tells him the assault was a mere prelude to something greater, something more final. He is right. Out of the Eye of Terror comes Abaddon the Despoiler, at the head of a warhost unmatched in scale since the dread days of the Horus Heresy.

As an agent of the Throne, former soldier Ianthe serves Inquisitor Covenant and faces some of the most dangerous and insidious threats the galaxy has to offer. On the hunt for the rogue psyker Silas Norn, Ianthe and her associates run afoul of the Imperial authorities and are imprisoned. Norn too is captured and incarcerated, but with the ability to manipulate the minds of his victims he is far from easy quarry. To stop him, Ianthe must not only find him; she must overcome the buried ghosts of her hidden past.

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.

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.