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.

The Sisters of Battle are the Emperor's most devout worshippers, fierce warriors preaching the purity of the Imperium and scourging their enemies with bolter and flamer. On a distant world, the Ecclesiarchy outpost of Sanctuary 101 was wiped out by an implacable foe - the fearless, soulless necrons. Now, a mission of the Sisterhood has returned to reconsecrate the site - but the metallic nightmares still lurk in the darkness, guarding a secret that has lain dormant for millennia.

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.

With her mighty wings spread wide and Ardent Blade aflame, Saint Celestine is the living embodiment of the God-Emperor’s wrath. Her halo blazes like a star upon the smog-wreathed, blood-soaked battlefields of the 41st Millennium; its holy light leading the faithful to victory time and time again. As heretics and daemons tear at her flesh, she calls down fires of retribution from on high to smite the wicked and unrighteous. If she is to fall in battle, none should mourn as she is Celestine, the Living Saint, and death is her duty.

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.

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.

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.

Uncompromising and fierce, Commissar Severina Raine has always served the Imperium with the utmost distinction. Attached to the 11th Antari Rifles, she instills order and courage in the face of utter horror. The Chaos cult, the Sighted, have swept throughout the Bale Stars and a shadow has fallen across its benighted worlds. A great campaign led by the vaunted hero Lord-General Militant Alar Serek is underway to free the system from tyranny and enslavement, but the price of victory must be paid in blood.

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.

Ufthak Blackhawk and the green tide descend upon Hephaesto - an Adeptus Mechanicus forge world bristling with loot - only to find it already under siege by the notorious Freebooter Kaptin Badrukk. When his warboss, Da Biggest Big Mek, orders temporary co-operation, Ufthak seeks to make a name for himself by crushing some of the Imperium’s most advanced defenders and claiming the greatest prize.

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.

When Horus fell, his Sons fell with him. A broken Legion, beset by rivalries and hunted by their erstwhile allies, the former Luna Wolves have scattered across the tortured realm of the Eye of Terror. And of Abaddon, greatest of the Warmaster's followers, nothing has been heard for many years. Until now....

For a thousand years, the Sabbat Worlds have been lost to the Imperium, claimed by the dread powers of Chaos. Now, a mighty crusade seeks to return the sector to Imperial rule. And at the forefront of that crusade are Colonel-Commissar Ibram Gaunt and the Tanith First and Only - better known as Gaunt’s Ghosts. Trapped in the grinding trench warfare of Fortis Binary, the Ghosts find themselves drawn into a conspiracy to assassinate the crusade’s leader, Warmaster Macaroth.

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.

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.