Gr 7–10—In this science-fiction mystery, Violet, 16, is found floating amid the wreckage of a plane crash with no memory of her life before the accident. A foster family has agreed to take her in until she regains her memories. Violet finds even everyday expressions and concepts to be maddeningly unfamiliar. The only clue to her identity is a locket with a cryptic equation inscribed on it. Soon a stranger named Lyzender arrives on the scene, claiming to know her. Violet feels drawn to him, but she is hesitant to trust the impossible story that he tells her. As she slowly discovers superhuman skills and knowledge that she cannot explain, however, the teen realizes that her real name is Seraphina and that she has no choice but to consider that what Lyzender is telling her is true. If it is, then she is in danger. Seraphina's strong voice, feeling of isolation, and desperate need to understand the world around her will ring true with teens. They will have a hard time putting this book down as they struggle to solve Seraphina's mystery alongside her. While other figures, such as Lyzender, are not well developed, the nonstop suspense and well-paced plot more than make up for what the story lacks in characterization. Hand this one to fans of romantic science fiction such as Jessica Khoury's Origin (Penguin), Lissa Price's Starters (Delacorte), or Rachel Cohn's Beta (Hyperion), all 2012).—Liz Overberg, Darlington Middle School, Rome, GA