​Seventeen-year-old Mineral Vyotto always planned on running away from the City and its annual Covalence Ceremony?a tradition forcing her to Bond with another of her Kind. In a hidden cavern outside the City gates, she starts collecting parts and Building a plane so she can bolt before the Ceremony takes place.

But when Covalence is moved up and she's almost caught by the Officials, Mineral finds herself and her fate at the hands of Amory Thames?an arrogant, opinionated Orderly with powerful parents who could ruin her chance at freedom. With only four weeks to escape the City before the Ceremony, Mineral and Amory must work together to find a way out?even if it means keeping Society's biggest secret to themselves and putting the lives of everyone they love at risk.