Seventeen-year-old Kai lives in a world of scattered islands, separated by dangerous oceans, predatory sea-monsters, and violent, magic-laced storms. Travel is perilous. Most never venture far from their homes - except the flyers - men and women who fly with harnessed wings, acting as messengers between the islands, bringing news - and warnings of danger. Kai dreams of joining the flyers. With them, she could see the world outside her home - and maybe even find her mother, who left for the Isle of Priestesses when Kai was very young. But training to be a flyer is difficult, especially coming from a small, backwater island. Kai must learn to fly and to harness the sea-magic that she barely understands. She will need to master these skills sooner than she thinks. For an uprising is building - a rebellion that has the potential to destroy both the home she's left behind and the flyers that she's started to call family...