Newly promoted to the captaincy of the Ultramarines Fourth Company, Uriel Ventris leads his warriors to the world of Pavonis, where vicious alien raiders are bringing death and destruction. As Pavonis descends into political turmoil, Uriel and his warriors must battle the xenos as they unravel a plot to unleash an ancient evil buried deep beneath the world - the mysterious and deadly Nightbringer.

A great darkness has befallen the galaxy, and the armies of Chaos are rampant. To survive, humanity must retaliate and take back what they have lost. By the will of the reborn primarch, Roboute Guilliman, is the Indomitus Crusade launched - a military undertaking that eclipses all others in known history. From the Throneworld of Terra does the Avenging Son hurl his fleets, their mission the very salvation of mankind.

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.

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.