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.

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.

The daemon prince Mortarion has emerged from the Eye of Terror at the head of a vast plague-horde, intent upon the corruption of the Imperium he once served. Under Supreme Grand Master Geronitan, the Grey Knights finally meet the daemon army in battle on the plains of Kornovin - a mobilisation of the Chapter the likes of which few have ever seen. Kaldor Draigo and his fellow brotherhood masters lead from the front, trusting to their lord's secretive plan...until Geronitan is unexpectedly struck down by the Death Lord.

The Inquisition moves amongst mankind like an avenging shadow, striking down the enemies of humanity with uncompromising ruthlessness. When he finally corners an old foe, Inquisitor Gregor Eisenhorn is drawn into a sinister conspiracy. As events unfold and he gathers allies - and enemies - Eisenhorn faces a vast interstellar cabal and the dark power of daemons, all racing to recover an arcane text of abominable power: an ancient tome known as the Necroteuch.

Abandoned by his primarch and left to lead the Space Wolves into an uncertain future, Bjorn the Fell-Handed is amongst the greatets of the sons of Russ. But even legends must fall, and when Bjorn meets his end on a distant world, his body broken beyond repair, his brothers battle to save him, and he remembers the events that brought him to this place...and realises his destiny.