Quint is traveling with his father, Wind Jackal, on a mission to track down and bring to justice Turbot Smeal, the man who started the fire that killed their family. Having left behind his studies at the Knights Academy, Quint is now eager to learn what it
really means to be a sky pirate and to learn from his father. But Wind Jackal is consumed by his desire to capture Smeal—and his judgment is flawed. His actions endanger the lives of his crew and his son. As they travel from the taverns and backstreets of Undertown and the wonders of the shipbuilders´ yards, to the dark dangers of the Deepwoods, where Quint and Maris become separated from the rest of the crew and encounter some terrifying creatures and finally to the mysterious, ghostly sky-wreck in Open Sky, where they discover the truth about Smeal—and face a new terror. . . .

In the great floating city of Sanctaphrax, Quint, the son of a sky pirate, has just begun his training at the Knights Academy. But when Quint breaks the rules and heads out to Open Sky on his own, he runs into the great sky leviathans known as cloud-eaters.