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.

There are those in the great expanse of the galaxy that seek profit wherever it is to be found: the deal makers, the opportunists and explorers – the Rogue Traders. Granted power by an ancient charter, sanctioned by the Emperor Himself, these scoundrels, entrepreneurs and adventurers roam the galaxy in search of fortune and glory. None perhaps are as hungry for these twin vices as Janus Draik.

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. The Siege of Terra looms, and the fate of the galaxy balances on a razor's edge.

It is M32, a thousand years after the Horus Heresy. The Scouring is over and the Imperium is at the height of its post-Crusade power. When Magnus the Red is tracked down to Gangava Prime, the Space Wolves hasten to engage the daemon primarch. Even as Great Wolf Harek Ironhelm closes on his ancient enemy, the Fang, a fortress on the Space Wolves home world, is besieged by a massive force of Thousand Sons. A desperate battle ensues as the skeleton forces of Wolf Lord Vaer Greylock attempt to hold back the attacking hosts before the last of his meagre defences gives in.