Matt, a young cabin boy aboard an airship, and Kate, a wealthy young girl traveling with her chaperon, team up to search for the existence of mysterious winged creatures reportedly living hundreds of feet above the Earth's surface. In a swashbuckling adventure reminiscent of Jules Verne and Robert Louis Stevenson, Kenneth Oppel, author of the best-selling Silverwing trilogy, creates an imagined world in which the air is populated by transcontinental voyagers, pirates, and beings never before dreamed of by the humans who sail the skies.