Former cabin boy Matt Cruse, now a student at the prestigious Airship Academy, is first to identify the Hyperion, the private airship of a reclusive and fabulously wealthy inventor that disappeared forty years ago with its owner. Armed with the Hyperion's coordinates, which only he possesses, Matt, heiress Kate de Vries, and a mysterious young gypsy board the Sagarmatha, an airship fitted with the new skybreaker engines that will allow them to reach the Hyperion, 20,000 feet above the earth's surface. Pursued by others who want the Hyperion and will stop at nothing to get it, and surrounded by dangerous high-altitude life forms, Matt and his companions are soon fighting not only for the Hyperion but for their very lives. In this thrilling sequel to Airborn, a Michael L. Printz Honor Book, Kenneth Oppel evokes the classic storytelling of Robert Louis Stevenson and Jules Verne, creating a world in which a new discovery can have unimagined consequences -- on earth and miles above it.