Eldura is a city-state surrounded by clouds and steep cliffs; flying is forbidden, and is generally considered a crime.
Knit is a spirited little boy with no family whose dream is soaring across the beautiful blue sky he admires every day. One day, a man called Shark crashes to the city on a flying creature called a Lindbergh. Lindberghs are wingless dragons that can kick the air, but for flying they need man-made wings.
Shark tells Knit that his pet, Plamo, is a Lindbergh too, and that outside Eldura all sorts of people fly with their own ones. But the outside world turns out to be even more different than Knit could have ever imagined.