In the jungles of Aztlan a deadly war of the shadows is being fought. And the Imperial Guard are losing. The alien t’au, though few in number, greatly outclass the soldiers of the Imperium and are taking a serious toll on their forces. A call for aid is answered by the fearsome Mortifactors Chapter, who come to the world full of grim purpose. Adoni, an unblooded neophyte yet to earn his place, is amongst the war party. As the Mortifactors descend into the jungle vastness, they hunt for a killer, one that will not die easily but that whom Adoni must slay if he is to become part of the Chapter and a Taker of Heads.

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.

Above a war torn battlefield on a distant world, Ko'tan Kadai and his Salamanders are on a mission of mercy. As the city burns, the Fireborn rescue a band of beleaguered civilians and learn what it means to be Vulkan's Shield.

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.