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.

The primarchs, nigh-immortal sons of the Emperor of Mankind, take the stage in a series of short stories showcasing some of their great deeds and hideous acts from across the Great Crusade and the Horus Heresy.

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.

As an agent of the Throne, former soldier Ianthe serves Inquisitor Covenant and faces some of the most dangerous and insidious threats the galaxy has to offer. On the hunt for the rogue psyker Silas Norn, Ianthe and her associates run afoul of the Imperial authorities and are imprisoned. Norn too is captured and incarcerated, but with the ability to manipulate the minds of his victims he is far from easy quarry. To stop him, Ianthe must not only find him; she must overcome the buried ghosts of her hidden past.

Ahriman is thrust into a deadly conflict with a creature of darkness whose cunning and thirst for power are the equal of his own - the first daemon prince, the dreaded Be'lakor.