The Polity is under attack from melded AI entity controlling the lethal Jain technology, but the attack seems to have no coherence. When one of Erebus's wormships kills millions of innocent civilians on Klurhammon, a high-tech agricultural world of no real tactical significance, Cormac is sent to investigate... though he is secretly struggling to control a new-found ability no human being should rightfully possess, while also beginning to question the true motives of his AI masters. Further attacks and seemingly indiscriminate slaughter ensue, but serve only to bring some of the most dangerous individuals in the Polity into the war. Mr. Crane, the indefatigable brass killing machine, sets out for vengeance, and Orlandine, a vastly augmented haiman also in control of Jain technology, is seeking a weapon of appalling power with the aid of some bizarre relics from an ancient war. Meanwhile Mika, scientist and Dragon expert, is again kidnapped by that massive alien entity and dragged into the heart of things: to wake the cerators of Jain technology from their five-million-year slumber. Then it begins to emerge that attacks by Erebus are not as indiscriminate as they seem, and could actually mean the beginning of the end for the Polity...