On the prison world of Zartak, darkness has fallen on arbitrators and inmates alike. The Night Lords have come, bringing with them the shadow of fear and pain. But these monsters are not the only ones with an interest in Zartak. From the void, running on silent, another fleet emerges. These Space Marine warriors are grey-clad and white-faced, and their eyes are as black as the Outer Dark – the savage Carcharodon Astra.

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 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.

Two centuries ago, the Imperium of Man and the upstart Tau Empire fought to a standstill in the Damocles Gulf. Now, as the 41st millennium draws to a close, the tau have returned. As the world of Agrellan falls under attack, the White Scars and Raven Guard rush to its defence, but with the skilled Commander Shadowsun leading the alien forces, the Space Marines and their allies are hard pressed. Kor'sarro Khan, Huntmaster of the White Scars, swears that he will win the day in the most direct way possible – by taking Shadowsun's head.

Kharn the Betrayer takes to the field of battle as the champion of his old comrade Argus Brond, but his own motives go far beyond the petty squabbling of rival Chaos warlords....