The Horus Heresy is over. The traitor Legions have scattered, fleeing the wrath of a vengeful Imperium. The World Eaters are leaderless, their primarch missing and their greatest hero, Khârn, locked in a coma. The surviving Legionaries have turned upon themselves, their Butcher's Nails driving them to ever-greater acts of berserk savagery. Poised on the brink of destruction, the Legion needs direction. 

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. 

The Great Crusade is ending. The Emperor has returned to Terra, while Horus remains among the stars to complete the unification of humanity. As the Imperial armies fight the final battles of the age, Remembrancer Solomon Voss seeks the answer to one question—why does Sigismund, First Captain of the Imperial Fists and greatest champion of the Legions, believe that war will not end? Granted a rare audience with the master of the Templars, the answer takes Voss on a revelatory journey to a time before Sigismund became a Space Marine.

The End Times are coming. With the hordes of Chaos marshalling in the north, Emperor Karl Franz leads his armies in defence of his realm. But when the worst happens, Reiksmarshal Kurt Helborg must return to Altdorf, the capital of the Empire. There, he must steel himself and prepare his soldiers to defend the jewel of the Empire from the corrupted advance of the forces of Chaos. As plague spreads and the defences weaken, all seems lost—until help arrives from a most unexpected source... if Helborg can bring himself to accept it.

The Indomitus Crusade continues its war across the stars. The primarch Roboute Guilliman has finally broken through the orkish threat bedevilling the sectors near Fenris, and makes ready to push on his bid to stabilise the Imperium Sanctus—but old and bitter foes stand in his way. Kor Phaeron, the Dark Cardinal, threatens the previously stable core of the Segmentum Solar. Waves of rebellion instigated by his infiltrating priests suggest an imminent, large-scale invasion by the Word Bearers Legion. 

The Officio Assassinorum safeguards the future of humanity. Its agents are the bloody-handed, secret saviours of the Imperium, killers charged with achieving the impossible...and Vindicare assassin Absolom Raithe has just been handed the most difficult assignment of his career.

In the ruined border town of Vincula, the newly formed Tanith First and Only and their commander, Colonel-Commissar Ibram Gaunt, are assigned to enforce a permanent peace. However, this thankless police action will prove as dangerous as any frontline—something is stalking the Ghosts through the streets, and soon the Tanith First will learn dark secrets about themselves that will echo through their history.

Of the billions of greenskins who swarm the galaxy, the name of one strikes fear into the hearts of human and xenos alike—Ghazghkull Mag Uruk Thraka. The Warlord of Warlords. The Beast of Armageddon. The Prophet of the Waaagh! With his tusks, fists and power claw, he does the holy work of Gork and Mork—and soon all worlds will burn in his bootprints. Mystery shrouds the origins of such a beast. Rumours abound that the mighty warlord was once just like any other ork—but if that is the case, how did he rise from a lowly lad to the biggest of bosses? 

Carried by six Sisters of Battle, each the embodiment of a revered saint, the funerary procession known as the Triumph of Saint Katherine marches from world to world, battlefront to battlefront. Where darkness and heresy are rampant, it brings faith, hope and courage to the warriors of the Imperium. Sister Avra of the Order of Our Martyred Lady is honoured beyond measure to battle alongside the sacred procession in defence of the beleaguered world of Kiros. However, this bold young warrior holds a secret shame in her heart, one she believes can only be redeemed in death.

Imperial commissar Ciaphas Cain returns to Nusquam Fundumentibus to crush the ork attacks which have been plaguing the frozen planet. But when his ship crashes into the wastelands outside the capital it disturbs a far greater enemy, one which has lain dormant under the permafrost since long before the Imperium came to this world and could now threaten the whole sector.

When Colonel Haskell 'Hell Fist' Aldalon and the Catachan 57th Jungle Fighters arrive on the quagmire world of Gondwa VI, they find it locked in the grip of an ever-growing greenskin threat. Rather than shoring up the meagre existing defences, the Catachans elect to go on the offensive and retake the strategically vital Outpost Four. In the process, they are saddled with the sole survivor of the outpost's fall—the barely trained Trooper Torvin, of the Skadi Second Infantry.

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.

The grand halls of Fenris grow ever quieter in the wake of the Space Wolves' arduous campaigns. Concerned by his Chapter’s diminishing numbers, the Great Wolf Logan Grimnar entrusts Njal Stormcaller with a task - to find a remedy for their plight. When a 10,000-year-old enemy embeds itself in the Rune Priest’s mind, it claims that the salvation he seeks lies where an ancient enmity began - on Prospero, the ruined home world of the Thousand Sons Legion. 

Urdesh is a brutal world, the fires of its forge-cities mixing with the many volcanoes and an endless expanse of battle wreckage littering the plains. When the reincarnation of Saint Sabbat herself appears on the blasted battlefields of Urdesh, powerful forces race to secure that which may decide the ultimate fate of the world, and the crusade at large. 

The successor Chapters of the Space Marines number in the hundreds, founded to fight for the survival of the Imperium. Across 13 short stories by 10 different authors, discover the history, customs and stories of 12 different successor Chapters, from famed warriors to unsung heroes.