After seven long years of conflict, the Horus Heresy nears its end. But now, as the Warmaster Horus marches on Terra to rip his father from the Throne, the seat of the arch-traitor’s power lies empty. Cthonia, a world once dominated by brutal murder-gangs, is occupied by the Emperor’s praetorians—the indomitable Imperial Fists. For the Sons of Horus, this outrage demands a reckoning.

In the heavens above Luetin Hive, Erik Morkai's Space Wolves clash with dark eldar raiders, jump-pack clad Blood Claws taking the battle to the aliens' own infernal airships. But the war will be decided by Morkai himself as he challenges the aliens' sinister leader to single combat.

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 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.

Lord Azariel, Head of the Navigator House Brobantis is dead. His widow and murderer, the Lady Chettamandey, stands to inherit his power and influence. Her plans for ascension are curtailed when she’s drawn into a dark world of ritual killings and cult murders. With planets being dragged into the warp seemingly at a whim, the threat to Chettamandey’s legacy is dire, and only she can avert potential disaster.

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 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.

Lord of Chemos and bearer of the Palatine Aquila, Fulgrim, primarch of the Emperor’s Children, is determined to take his rightful place in the Great Crusade, whatever the cost. A swordsman without equal, the Phoenician has long studied the art of war and grows impatient to put his skills and those of his loyal followers to a true test. Now, accompanied by only seven of his finest warriors, he seeks to bring a rebellious world into compliance, by any means necessary.

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.