For too long had the Vth Legion ranged out beyond the sight of the wider Imperium, remaining ignorant of the Warmaster's rebellion and the war that inevitably followed. Only once their primarch, Jaghatai Khan, had satisfied himself that the path before them was just and true did the White Scars choose a side, taking the fight to the traitors on every front.

With the noble Emperor Sanguinius ruling from Macragge, Imperium Secundus stands as a lone beacon of hope even as the Warmaster's forces continue to ravage the rest of the galaxy. Roboute Guilliman, still Master of Ultramar, has convinced his brother that Terra has fallen and that the mysterious Mount Pharos on Sotha now holds the key to mankind's future.

While loyalist and traitor forces clash on a thousand battlefields across the galaxy, a very different kind of war is being fought in the shadows - a war of subtlety and subterfuge, unknown to many, but one that surely holds the key to victory for either side. Rogal Dorn and his Legion prepare to defend the Solar System against the armies of Warmaster Horus, even as Malcador the Sigillite charges his many agents and spies with missions of the utmost secrecy. The future of the Imperium is being shaped by unseen hands....

The Emperor's vision of mankind ascendant lies in tatters. The Great Crusade is naught but a fading memory. The dream of Unity is no more. But with Horus's rebellion spreading to every corner of the Imperium and war engulfing new worlds and systems almost daily, there are some who now ask: were the signs there to be seen all along?

With the Dark Angels spread across a hundred systems, primarch Lion El'Jonson stands as Lord Protector of Ultramar - though his true motives are known to few indeed, and old rivalries on the home world threaten to tear the Legion in half. But when word comes of the Night Lords' attack on Sotha, the Lion's brutal actions bring Imperium Secundus once again to the brink of civil war.

Recalled from the Great Crusade after Ullanor, Rogal Dorn and the VIIth Legion were appointed as the Emperor's praetorians - but only after the Warmaster's treachery was revealed did the full extent of that sacred duty become apparent. Now, the Solar System comes under attack for the first time since the war began, and many of the seemingly impregnable defences wrought by the Imperial Fists prove inadequate. With all eyes fixed firmly upon this new threat beyond the gates of Terra, who in turn will protect Dorn from the enemy within?

After Isstvan, after Deliverance, the Raven Guard still endure. Their primarch Corvus Corax has rallied countless warriors to his banner, striking back at the forces of the Warmaster on every front - from the degenerate hereteks of the Mechanicum to the cruel legionaries of the Sons of Horus, none shall escape his wrath. But although Corax has managed to stall the physical corruption of his own Space Marines, what of their spirit? And what sinister end must await those who dwell forever in the darkness?

Only from out of great conflict can true heroes arise. With the galaxy aflame and war on an unimaginable scale tearing the Imperium apart, champions of light and darkness venture onto countless fields of battle in service to their masters. They ask not for remembrance or reward - simply to meet their destiny head-on, and only by embracing that destiny will they come to learn what the unseen future may yet hold for them....

In the aftermath of the Dropsite Massacre at Isstvan V, a battered and bloodied force of Iron Hands, Raven Guard and Salamanders regroups on a seemingly insignificant death world. Fending off attacks from all manner of monstrous creatures, the fractious allies find hope in the form of human refugees fleeing from the growing war and cast adrift upon the tides of the warp.

From out of the shadows of the Silent War, a hero emerges. Clad all in grey, an errant warrior of the Legiones Astartes kneels before the Regent of Terra, and accepts a solemn new duty - Battle-Captain Garro, once commander of the Eisenstein, now Agentia Primus of Malcador the Sigillite. From the desolation of Isstvan to the halls of the Imperial Palace itself, he stands as a paragon of loyalty and protector of the innocent, ever ready to strike back at the traitorous allies of the Warmaster.

Once the brightest star in the Imperium and always first among his primarch brothers, Horus has dragged the Space Marine Legions into the bloodiest conflict that the galaxy has ever seen. While their allies wage war on a thousand different fronts, the XVIth Legion descend upon the Knight world of Molech - home to the ruling House Devine, and a principle stronghold of the Imperial Army.

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.

Imperium Secundus lies revealed as a heretical folly. Terra has not fallen, though it remains inaccessible. Sanguinius, Guilliman and the Lion El’Johnson, the primarchs of the Triumvirate, must reach Terra at all costs. They seek to defend the Emperor and to atone for their sins. But the Ruinstorm, a galaxy-wide maelstrom of chaos, hides the Throneworld from the primarchs. Now the fleets of three Legions depart Macragge, and the primarchs will stop at nothing to overcome the Ruinstorm.

Removed from the concerns of the galaxy at large and regarding the Warmaster's unfolding Heresy with cold detachment, he has dedicated his hollow existence to the preservation of all the knowledge once held in the great libraries of Tizca, should mankind ever seek such enlightenment again. But his sons can see the change in their primarch - he is a broken soul whose mind and memories are slipping away into the tumult of the warp.

As the Warmaster's campaign of galactic domination continues, his generals seek out fresh battlefields to conquer. After leaving the Crone World of Iydris behind, Perturabo strikes for Tallarn. A bitter, vengeful primarch, the lord of the Iron Warriors unleashes a deadly bombardment against the world, killing millions but entrenching the survivors. A brutal, all-consuming armoured conflict ensues, the greatest of the war and one that grinds down all combatants over more than a year of relentless battles.