Cole Randolph goes with his friends Dalton and Jenna Hunt and some other sixth graders to a haunted house. There the group is kidnapped, except Cole, and taken away. Cole follows them, wanting to rescue his friends. He finds himself and his friends in The Outskirts, an in-between place far from Earth.
He attempts to rescue his friends but is enslaved and sold to the Sky Raiders. There he helps them raid derelict floating castles. While on a mission, his party is deceived and he is stranded with a slave girl and her mentor, both of whom are shapers. The mentor dies creating a craft to take Cole and Miracle (known as Mira) back to the Sky Raiders.
After returning, an army from the High King comes to take Mira to Junction, capital of The Outskirts. Cole, Jace, and Twitch help Mira escape. They pass through the Eastern Cloudwall and discover a hidden castle, home of Declan the high shaper of Sambria. Cole, Jace, and Twitch learn that Mira is actually the High King's daughter whose power had been stolen by the High King but is now slowly returning.