The Imperium's attempts to defeat the ork menace seem doomed to failure; it is only a matter of time before the greenskins triumph, and mankind is wiped from the galaxy. Yet there is some cause for hope - the psychic weakness of the orks has been found, and a few Sisters of Silence survive. Supported by the full might and technology of the Adeptus Mechanicus, the Space Marines head to the orks' home world one final time. This time there will be no retreat, no surrender. They must succeed...or die in the attempt.

The attempt to hunt down and kill the orks' leader has ended in catastrophe. The Imperium is reeling from the loss of so many beloved heroes, and the military forces of mankind have been reduced to tatters. Koorland now knows that brute force is not the answer - but how else can the orks be fought? In a radical move, he creates small, mixed Chapter units of Adeptus Astartes - compact teams that will hit the enemy hard and fast and with deadly accuracy.

Across the length and breadth of the galaxy, humankind celebrates its salvation and relishes the prospect of a return to peace. But the war against the orks has driven the political bedrock of the Imperium, exposing its rotten core. One man, one powerful man, decides he has the solution and launches a campaign of destruction so terrible that thousands of years later his actions will still be viewed with horror.

The Imperium has been brought to the edge of extinction by an ork invasion of unprecedented scale and depth. Piecemeal strikes against the invaders prove ineffective - for every ork fleet destroyed, five more appear. The only solution is to find and kill the orks' warlord - the Great Beast. Surely if its leader is killed, the greenskins' empire will fall apart in agony of infighting and confusion.

Tearing itself apart from within, the Imperium is still virtually powerless to resist the ork advance. When the Adeptus Mechanicus reveal they have discovered the orks' point of origin, the Adeptus Astartes start to gather their forces for a massive assault on their enemy's home world. But what the Imperial forces need is a figurehead, a hero from legend to lead them - a primarch.

The Imperium's situation has never been more grim - an ork attack moon hangs over Terra, and ork armadas ravage human space. To make matters even worse, eldar strike at the heart of the Imperial Palace, forcing humanity's defenders to fight on two fronts at once. Though it seems nothing can stop the orks - neither brute force, science, nor faith - an unlikely alliance in the furthest reaches of space uncovers the first clue how to defeat the greenskins. The Adeptus Astartes now face an almost impossible task....

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.  

Despite the Imperium's best attempts to forestall the ork plague that is wreaking havoc in human space, an ork attack moon now hangs over Terra. As its malevolent presence gazes down at the Imperial Palace, terrified citizens run riot in the streets. In a last-ditch attempt to destroy the attack moon, a proletarian crusade is launched. Thousands of ships large and small head to the moon carrying billions of citizens, all eager to take the fight to the enemy.

As ork ships lay waste to world after world, heading inexorably towards Terra, Imperial citizens despair. The High Lords become desperate to prove that victory is possible, no matter the cost. A massive navy fleet is assembled - their mission to make a definitive strike against the orks at Port Sanctus, an area of enemy-held space. But when the Imperial armada arrives, they find themselves outclassed and outmanoeuvred. Can human courage and faith possibly prevail against such terrible odds?

Ciaphas Cain's latest mission takes him and his Valhallan regiment to the planet of Adumbria to defend against an approaching Chaos invasion. However, infighting with fellow Imperial Guard regiments from the world of Tallarn, commanded by an old 'friend' of Cain's from the Schola Progenium and the uprising of a sinister cult on the planet puts paid to any hopes of an easy life.

It is the 32nd millennium, and the Imperium is at peace. The Traitor Legions of Chaos are but a distant memory, and the many alien races that have long plagued mankind are held in check by the Space Marines. When a mission to exterminate one such xenos breed on the world of Ardamantua draws in more of their forces, the Imperial Fists abandon the walls of Terra for the first time in more than a thousand years.

The Traitor Host of Horus Lupercal tightens its iron grip on the Palace of Terra, and one by one the walls and bastions begin to crumple and collapse. Rogal Dorn, Praetorian of Terra, redoubles his efforts to keep the relentless enemy at bay, but his forces are vastly outnumbered and hopelessly outgunned. Dorn simply cannot defend everything. Any chance of survival now requires sacrifice, but what battles dare he lose so that others can be won? Is there one tactical stroke, one crucial combat, that could turn the tide forever and win the war outright? 

As Guilliman, Regent of Terra, heads off to lead the Indomitus Crusade, he leaves behind a world still in turmoil, beset by cult activity. Stripped of its huge armies for the galactic offensive, recovery is precarious. The Custodians do what they can while keeping the Palace secure, and the Sisters of Silence rebuild their citadel on Luna. When the warship Phalanx returns, it seems that stability will at last be assured. However, as reconquest forces push out further into the slums, they come across signs that another mysterious foe is active.

Constantin Valdor. It is a name that brings forth images of heroism, honour and peerless duty. For it is he who commands the will of the Legio Custodes that most esteemed and dedicated cadre of elite warriors. He is the Emperor’s sword, His shield, His banner and he knows no equal. Clad in shining auramite, his fist clenched around the haft of his Guardian Spear, he is the bulwark against all enemies of the throne, within or without. Nearing the end of the wars of Unity, Valdor’s courage and purpose is put to the test as never before. 

The war for the fate of mankind blazes on. Though the outer defences have fallen, the walls of the Palace itself remain inviolate as Rogal Dorn, the Praetorian of Terra himself, uses every known stratagem and ploy to keep Horus' vast armies at bay. In Perturabo, the Traitor siegebreaker, Dorn faces an adversary worthy of his skill. A terrible, grinding attrition ensues. The crucial battle for the Lion's Gate spaceport is at the heart of this conflict. With it in their possession, the Traitors can land their most devastating weapons on Terran soil. Dorn knows it must not fall.