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.

It is the 41st millennium, and an upstart alien empire has emerged on the Eastern Fringe. After a few skirmishes to retake human worlds from these blue-skinned invaders, the time has come to strike against the so-called Tau Empire. At the forefront of the Damocles Crusade stand the Ultramarines, commanded by Captain Atheus, the Chapter's Lord Executioner.

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.

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.