The novel begins with the Tanith First training to take part in the airborne assault on Cirenholm, a dome-city perched above Phantine's toxic Scald. The archenemy's elite Blood Pact have captured the city, which the Imperial forces plan to use as a staging ground for their campaign to reclaim Ouranberg, one of Phantine's largest cities and a major source of promethium. After the Ghosts successfully infiltrate the Blood Pact's defences and prevent a disastrous loss for the Imperium, Lord-General Van Voytz re-considers his approach on the Ouranberg invasion.