Two centuries ago, the Imperium of Man and the upstart Tau Empire fought to a standstill in the Damocles Gulf. Now, as the 41st millennium draws to a close, the tau have returned. As the world of Agrellan falls under attack, the White Scars and Raven Guard rush to its defence, but with the skilled Commander Shadowsun leading the alien forces, the Space Marines and their allies are hard pressed.

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.

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. 

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?  

In the Pandorax System, on the death world of Pythos, an ancient secret that has laid buried for millennia has been unearthed.... Ignorant of this terror, troopers of the Catachan 183rd, stranded on Pythos and under the command of Colonel 'Death' Strike, find themselves under attack by the forces of Chaos. Daemons in their thousands flock the sky, and none other than Warmaster Abaddon leads the attack.

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.

Lieutenant Heyd Calder is a Primaris Marine whose mastery of warfare is matched only by his diplomatic prowess. Under the orders of Roboute Guilliman, he is deployed to Almace, a minor seat of the Ecclesiarchy, to protect the world at whatever cost. Yet even as diabolical forces leer from the system's edge, Calder discovers that the capital's Cardinal-Governor, a sharp, inscrutable figure of spiritual and material authority, is hiding something. When it becomes clear that conquest is not the enemy’s sole aim, Calder resolves to uncover the secret of Almace. 

The Blood Angels Chapter of Space Marines is under threat. Having obliterated all human life in the Red Scar region of space, the largest tendril of Hivefleet Leviathan ever seen in the Imperium has converged and is making relentlessly for Baal. To face this awesome foe, Commander Dante has called upon the Successor Chapters of the ancient Ninth Legion. The Sons of Sanguinius gather in numbers not seen since the dark days of the Horus Heresy. 

The Custodian Guard have stood watch over the Emperor's Palace on Terra since the foundation of the Imperium. Charged with protecting the Master of Mankind from all threats, within and without, their fearsome resolve is renowned throughout the galaxy, and their golden armour is the last thing that a would-be assassin or saboteur will ever see.

The scattered worlds of the Elara's Veil nebula were once protected by the oath of unity sworn by three mighty Chapters of the Adeptus Astartes. The Star Scorpions were undone by flaws in their genetic coding. The Celestial Lions were ravaged by the Inquisition for sins they did not commit. Now, after hundreds of years, only the Emperor's Spears still keep their vigil. They are barbarian watchmen against the Outer Dark, bloodied but unbroken in their long duty.   

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.  

Best-selling author Dan Abnett turns his hand to the mighty Space Marines! The war-torn far future is laid bare as Brothers of the Snake follows the exploits of the Iron Snakes Space Marines as they battle against the enemies of mankind. First appearing in the pages of Inferno! magazine, the Iron Snakes Space Marines quickly gathered a loyal following, and now they wage war in a full-blown adventure, battling aliens and heretics as they defend the Imperium. 

In the hellish sprawl of Imperial Terra, Ordo Hereticus Inquisitor Erasmus Crowl serves as a stalwart protector, for even the Throneworld is not immune to the predations of its enemies. In the course of his duty, Crowl becomes embroiled in a dark conspiracy, one that leads all the way to the halls of the Imperial Palace. As he plunges deeper into the shadowy underbelly of the many palace districts, his investigation attracts the attention of hidden forces, and soon he and his acolyte Spinoza are being hunted.

Sons of the primarch Roboute Guilliman, the Primaris Ultramarines are peerless warriors whose sworn duty is to protect mankind from the predations of the xenos and the foul traitors of the Heretic Astartes. In a galaxy riven by eternal war, they and the other armies of the Imperium are all that stand between mankind and damnation. Their ship damaged by warp storms, the Ultramarines of strike force Cassian make for Kalides Prime. Also within this book is a host of awesome short stories to give you a flavour of the many warring armies that exist within the worlds of Warhammer 40,000.