The Horus Heresy is a civil war on a scale the likes of which the galaxy has never seen before. After the Great Crusade united the disparate worlds of humanity, the very warriors who made it possible turned on each other and tore it apart. The Siege of Terra looms, and the fate of the galaxy balances on a razor's edge.

After the Great Crusade united the disparate worlds of humanity, the very warriors who made it possible turned on each other and tore it apart. This war was not only fought on a galactic scale – it was contested a million times over in brutal battles between former brothers and allies. Since the near-destruction of the Iron Hands, Raven Guard, and Salamanders on Isstvan V, scattered warbands from these 'Shattered Legions' have waged a guerrilla war on Horus' forces across the galaxy.

The Horus Heresy is a civil war on a scale the likes of which the galaxy has never seen before. After the Great Crusade united the disparate worlds of humanity, the very warriors who made it possible turned on each other and tore it apart. Soon after word reached Terra of Horus's nascent rebellion, Mars fell. Set upon by the forces of the Alpha Legion before they had even recovered from the Razing of Prospero, the Space Wolves have been hounded to the edge of the Alaxxes Nebula. In desperation, Leman Russ called out to his primarch brothers for aid. None came.

For nearly 10 millennia, the Crimson Fists waged war against the enemies of mankind from their home planet of Rynn's World. And then, in one cataclysmic event, Rynn's World fell, despoiled by the hordes of the orks. Six months later, Chapter Master Pedro Kantor leads the shattered remnants of his Space Marines in pursuit of a force of greenskins still clinging to life in the mountains of the devastated world.

For Ianthe, war is all too familiar. A former soldier in the Astra Militarum, she now serves Inquisitor Covenant as an agent of the Throne. Her first mission sees her investigating a cult called the Children of Eternity. Falling foul of the local Enforcers, Ianthe soon learns that war in the shadows is seldom straightforward and that the local, angry law-keepers are the least of her troubles.

There are those in the great expanse of the galaxy that seek profit wherever it is to be found: the deal makers, the opportunists and explorers – the Rogue Traders. Granted power by an ancient charter, sanctioned by the Emperor Himself, these scoundrels, entrepreneurs and adventurers roam the galaxy in search of fortune and glory. None perhaps are as hungry for these twin vices as Janus Draik.

The Honoured joins the survivors from both sides in the immediate aftermath of the attack on Calth as they are driven into the subterranean arcology shelters by the tortured Veridian star. While their primarch, Roboute Guilliman, had planned for many seemingly unthinkable eventualities, the Ultramarines now face a new war in the underworld. The Unburdened follows Kurtha Sedd of the Third Hand Chapter of the Word Bearers. Garro: Vow of Faith tells the continuing story of Nathaniel Garro.

Nearly a quarter of a million loyal Space Marines lost their lives on Isstvan V. The Dropsite Massacre lasted only a few hours, and yet the Iron Hands, Raven Guard, and Salamanders were slaughtered by those they had once called kin. Corax: Soulforge follows the defiant Raven Guard in the wake of Corax's failed plans to rebuild his Legion after the Dropsite Massacre.

The Horus Heresy is a civil war on a scale the likes of which the galaxy has never seen before. After the Great Crusade united the disparate worlds of humanity, the very warriors who made it possible turned on each other and tore it apart. When he is cut off from his brothers and sons and lost in the darkness, can Ferrus Manus reign in his aggression long enough to heed a warning that could change his dark destiny?

The Horus Heresy is a civil war on a scale the likes of which the galaxy has never seen before. After the Great Crusade united the disparate worlds of humanity, the very warriors who made it possible turned on each other and tore it apart. As word of Horus's treachery spreads to fully half of the Legiones Astartes, Terra looks to the remaining loyalist Space Marines to defend the Imperium.