Several hundred years in the future, one boy has the chance to fly-but at what cost?When 13-year-old Keith Arlo's family receives word that his aunt and uncle have unexpectedly passed away, he is sent to collect Lulu, his 6-year-old cousin, and bring her back to live with them. Most people in Keith's country live in one of seven cities surrounded by nature, and most people do not travel far, so Keith is excited to finally experience train travel. On the journey, he happens upon a man who's involved with the mysterious Project F, and he cannot contain his curiosity. Even after he returns home, Keith keeps thinking about the project and its wonders. Project F has a darker side, however, one that is tied to the times that came before, the use of fossil fuels, and the massive changes humanity experienced long before Keith's birth. Meanwhile, Lulu struggles with the loss of her parents and the large secrets that she carries. This deliberately paced story, reminiscent in tone to older classics but original and timely in its subject matter, explores issues of environmental degradation, renewable energy, and how the future might be shaped. The narrative is satisfying and the questions prescient; young readers looking for something slightly different will enjoy speculating about how our future might appear. Main characters appear to be white.A compelling, nostalgic-feeling story exploring contemporary issues in a futuristic setting. (author's note) (Post-apocalyptic. 8-12)