Newly promoted to the captaincy of the Ultramarines Fourth Company, Uriel Ventris leads his warriors to the world of Pavonis, where vicious alien raiders are bringing death and destruction. As Pavonis descends into political turmoil, Uriel and his warriors must battle the xenos as they unravel a plot to unleash an ancient evil buried deep beneath the world - the mysterious and deadly Nightbringer.

The Great Devourer is descending on the world of Tarsis Ultra, but to defeat the xenos horrors, Captain Uriel Ventris may have to embark upon a dangerous and unorthodox mission.

The primarch Roboute Guilliman of the Ultramarines has returned in the galaxy’s hour of need, and all muster to his Indomitus Crusade to hold back the darkness. Amongst these heroes is Cato Sicarius, Master of the Watch and vaunted captain of Second Company. Disaster befalls Sicarius and his brave warriors as their ship, the Emperor’s Will, is lost to the hellish warp, its entire crew believed slain. But Sicarius endures, though he and his men are fighting for their very survival against the denizens of the Great Rift - the daemons and renegades of Chaos.

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.

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.

Attached to Crusade Fleet Quintus - dubbed the Cursed Fleet by many - the Ultramarines of the Ithraca’s Vengeance are drawn to a stricken world. With millions enslaved, a malign necron technology siphons the souls of the innocent and heralds the Silent Kingdom’s expansion. The Ultramarines face an impossible decision: mount a desperate last stand to destroy the Pariah Nexus, or break away and damn the entire sector to bring word of this ancient foe’s resurgence to the only being capable of halting it - the Lord Primarch Roboute Guilliman.

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.

Supreme Grand Master Azrael summons Lazarus and his Fifth Company to honour an old debt on the Knight world of Reis – a planet upon which the warp has set its hungry gaze. But Lazarus is not so sure Reis wants to be saved – its Knights are long lost, its governance is dogged by political strife, and internecine conflict hampers the world’s defence against an ancient evil. ­An evil which, like Lazarus himself, refuses to die.

The fortress world of Regium has a proud history, For millennia, it has endured when others have fallen to ruin and damnation, standing defiant in defence of the Imperium of Man. But now it is shaken. Parasitic plagues run rampant, and Regium's citizens are haunted by dreams of horrific monsters feasting upon their flesh and marrow. Lieutenant Castamon of the Ultramarines recognises these signs of an impending Tyranid invasion all too well. Rallying his warriors, the battle-hardened veteran launches a strike force to slaughter the xenos in the outer system, before it can reach Regium.

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?

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.

Under almost constant besiegement by the hosts pouring from the Eye of Terror, Cadia acts as a bulwark against tyranny and death. Its fortresses and armies have held back the hordes of Chaos for centuries, but that grim defiance is about to reach its end. As Abaddon's Thirteenth Black Crusade batters Cadia's defences, and armies of the Imperium flock to reinforce this crucial world, a terrible ritual long in the making comes to fruition and the delicate balance of this brutal war shifts.

On the prison world of Zartak, darkness has fallen on arbitrators and inmates alike. The Night Lords have come, bringing with them the shadow of fear and pain. But these monsters are not the only ones with an interest in Zartak. From the void, running on silent, another fleet emerges. These Space Marine warriors are grey-clad and white-faced, and their eyes are as black as the Outer Dark – the savage Carcharodon Astra.

The primarchs, nigh-immortal sons of the Emperor of Mankind, take the stage in a series of short stories showcasing some of their great deeds and hideous acts from across the Great Crusade and the Horus Heresy.

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.