In this novel that unites characters from "The Giver" and "Gathering Blue," Matty, a young member of a utopian community that values honesty, conceals an emerging healing power that he cannot explain or understand.

Mori and her friends set out to seek help for Ilana from Dr. Varden, one of the founders of Old Harmonie, but meeting Outsiders gives them new perspective on their utopian community.

Althought Felina the cat queen is gone, the subway tunnels are still dangerous, not only because of Hopper's rogue brother Pup and his arachnid companion Hacklemesh, but also due to a secret Firren has been hiding that worries her more than the disappearance of her daughter, Hope. Includes a bonus story, Atlantia Rising: How it All Began.