Set in 1938, in a backwater corner of the South Pacific, a young American adventurer and his ragtag group of friends become involved in death-defying hijinks, transporting people-on-the-run in a well-worn Grumman Goose seaplane.

It's the dawn of the golden age of aviation on planet Prester, and retro-futuristic sky vehicles known as vanships dominate the horizon. Claus Valca--a flyboy born with the right stuff--and his fiery navigator Lavie are fearless racers obsessed with becoming the first sky couriers to cross the Grand Stream in a vanship. But when the high-flying duo encounters a mysterious girl named Alvis, they are thrust into the middle of an endless battle between...