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.

After a series of victories, the Imperial forces are on the back foot once more. The power of Chaos is rising, the Traitors gain ground, and all hope seems lost. Can Terra endure? 

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? 

After seven years of bitter war, the end has come at last for the conflict known infamously as the Horus Heresy. Terra now lies within the Warmaster’s sights, the Throneworld and the seat of his father’s rule. Horus’ desire is nothing less than the death of the Emperor of Mankind and the utter subjugation of the Imperium. He has become the ascendant vessel of Chaos and amassed a terrible army with which to enact his will and vengeance. But the way to the Throne will be hard as the primarch Rogal Dorn, the Praetorian and protector of Terra, marshals the defences.

Of all the Emperor’s sons who fell to Chaos, it is perhaps Magnus the Red whose tale is the most tragic. Sanctioned because of his desire for knowledge, chastised, judged, and shattered to his very elements – there is much for the Crimson King to feel vengeful for. Yet revenge is not the only thing that draws him to Terra alongside the Warmaster’s besieging armies. He seeks something, a fragment, the missing piece of himself that lies within the most impregnable place on the planet – the inner sanctum of the Imperial Palace.

The paths of Roboute Guilliman and his fallen brother Mortarion bring them inexorably together on Iax. Once a jewel of the Imperium, the garden world is dying as the plans of the Lord of Death to use it as a fulcrum to drag the stellar realm of Ultramar into the warp come to deadly fruition. While Guilliman attempts to prevent the destruction of his kingdom, Mortarion schemes to bring his brother low with the Godblight, a disease created in the Cauldron of Nurgle itself, made with the power to destroy a son of the Emperor. 

In the void and upon the worlds of Greater Ultramar, the battle for the Imperium continues. Intent on rebuilding his home realm and using it as a base to reconstruct the ravaged stellar empire of mankind, the returned primarch, Roboute Guilliman, proceeds with his war to drive Mortarion and his Death Guard Traitor Legion from the domain of the Ultramarines. But when Guilliman brings his brother to battle upon the diseased plains of Parmenio, the intervention of a greater power in their fraternal struggle threatens to upend the Imperial Regent’s understanding of the galaxy. 

The Shattered Legions crew of the Sisypheum, broken and at the end of their endurance, find themselves divided - torn between following their resurrected captain on a suicidal mission or obeying orders to return to Terra and rejoin their Legion brothers. Following a series of garbled messages intercepted by the Kryptos, the divided warriors descend to the shattered surface of Luna. Here, their bonds of loyalty, duty, and their devotion to one another will be tested as ancient horrors of the earliest days of gene-manipulation are unleashed, and a long-buried secret is revealed.

On the battlefields of Aexe Cardinal, the stalwart forces of the Imperial Guard are locked in a deadly stalemate with the dark armies of Chaos. Colonel-Commissar Ibram Gaunt and his regiment, the Tanith First and Only, are thrown headlong into the living hell of trench warfare, where death by an unseen enemy is always just a moment away. The only chance for Gaunt and his lightly armed scouts to survive is to volunteer for a mission so dangerous that no one else dares accept it.

Legends abound of the glorious - or infamous - deeds of the emperor's sons. Yet almost nothing is known of Alpharius, the most mysterious of them all, for the lord of the Alpha Legion is unparalleled in the art of obfuscation. Such are his gifts of secrecy and deceit that even his rediscovery has remained an enigma - until now. But when the tale comes from the serpent’s mouth, where do the lies end and the truth begin?

Horus’ armada gathers, and he has defeated all enemies sent against him, even the Emperor’s own executioner. One barrier remains before he can strike for Terra and lay waste to the Emperor’s dream. The Beta-Garmon system occupies the most direct and only viable route to the Solar System and Terra. To break it, Horus assembles a war host of incredible proportions and Titans in untold numbers. To lose here is to lose the war, and Horus has no intention of turning back. But the Imperium understands the importance of Beta-Garmon too. 

While Horus' rebellion burns across the galaxy, a very different kind of war rages beneath the Imperial Palace. The 'Ten Thousand' Custodian Guard, along with the Sisters of Silence and the Mechanicum forces of Fabricator General Kane, fight to control the nexus points of the ancient eldar webway that lie closest to Terra, infested by daemonic entities after Magnus the Red's intrusion.

Cadia, 10,000 years a stalwart bastion against Chaos, is broken. Its collapse at the hands of Abaddon and the Thirteenth Black Crusade has fractured the Imperium of Man, and in its wake spreads the seeds of heresy, lies and insurrection. It falls to Cadia’s survivors to fight on, bloodied but unyielding, in the name of the Emperor. On the world of Malouri, traitorous forces have retreated to the impregnable island fortress of Crannog Mons.

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 galaxy is in flames. Chaos is in the ascendant across the stars. The Great Rift has split the holdings of the Imperium in twain, isolating entire sectors from the light of Holy Terra. But all hope is not lost. The Primarch Roboute Guilliman has returned from deathless sleep and appointed Commander Dante, lord of the Blood Angels, as Regent and Warden of the newly dubbed Imperium Nihilus. In the Baal system, the shattered holding of the Chapter is being rebuilt, and Dante plans the greatest campaign of his long life, to retake half an empire.