Aerius, one of the worlds of the great Imperium, is engulfed in a monstrous plague epidemic. According to the Oracle's prophecy, the only thing that can save the dying planet is the Talisman of Lykos. But two thousand years ago, this artifact was split into three parts and carried to different ends of the galaxy. The Inquisition is making a Herculean effort to reunite the Talisman. The Order of the Space Wolves sends a detachment of Bloody Claws to help the inquisitors, including the young Ragnar. Battles with orcs and tyranids become only a prelude to a fateful battle on which the future of not only Aerius, but the entire Imperium depends.