The feral warrior-kings of Fenris, the Space Wolves are the sons of Leman Russ. Savage heroes, few can match their ferocity in battle. After half a century apart, Space Wolves Ingvar and Gunnlaugr are reunited. Sent to defend an important shrine world from the plague-ridden Death Guard, the Grey Hunters clash with the pious Sisters of Battle—who see the Space Wolves as little better than the enemy they fight. As enemies close in around them and treachery is revealed, Gunnlaugr and his warriors must hold the defenders together.

On the grim death world of Fenris, the Space Wolves Chapter selects its aspirants from the best and brightest of the young tribesmen. Ragnar of the Thunderfist tribe finds his life changed forever when he is chosen. After being revived from a savage death on the battlefield, Ragnar is recruited into the fearsome Space Wolves Chapter. He is then thrown into a galactic war against the dark forces of Chaos. However, the implanting of the Canis Helix unleashes his primal instincts and Ragnar must fight to control the beast within him.

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.

Glory returns to Fenris. Magnus the Red and his traitorous legion are defeated upon the icy cliffs of the Space Wolves’ home world, their hollow remains scattered into the darkest depths of the World Sea. Yet Ragnar Blackmane, the youngest Wolf Lord in his Chapter’s noble history, does not feel victorious. He is uneasy. Uncertain of his purpose and place in the great war for the Imperium. Until a vision strikes him of a terrible beast, one greater than any he or his warriors have faced before. 

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.