Following the dramatic showdown in Seattle, brothers Jesse Fisher and Cassius Stevenson find their world has been turned inside out. The faculty at Skyship Academy is keeping Jesse prisoner in his own home, fearful of his influence over the Pearls. Meanwhile, Cassius has fled to the Polar Cities of Canada, where the Unified Party he deserted threatens retaliation at every turn.
When Jesse smuggles a mysterious red Pearl onboard the Academy, he sets loose a destructive chain of events, leading him to a reunion with Cassius and a confrontation with Theo, a bloodthirsty Pearlhound with a dangerous secret. But a larger threat looms in the stars. An enemy is gathering with devastating plans for the entire human race. And Jesse and Cassius might just be the lynchpins that trigger mankind's destruction.