A teenager who can grasp alien symbols becomes the key to resisting a megacorporation in this debut YA sci-fi novel. In 2038, Earth is dense with huge, overcrowded apartment buildings populated by a workforce for enormous factories that cheaply manufacture goods sold at high prices in wealthy, luxurious off-world colonies. Militarized robots police the worker bees, and information is highly censored. Samuel Hughes sees only one way to help his unemployed father, William, and gravely ill sister: by working in Tricium Group's off-world mines. It's dangerous, and William warns Sam that stories of mining wealth are just propaganda, but the boy is determined, and at age 15, he's old enough. But then he and other miners barely make it from their crashing transport ship to an escape pod, which lands on an Earth-like planet uninhabited by people or animals, although ruins are visible to the north. The survivors include nine men and eight women; the youngest are Sam and Rebecca Helmsford. The pod contains food and other supplies, but the survivors have to scatter when huge robots begin attacking. Sam and Rebecca flee with Tamrun Jones, a tall ex-soldier whose calm leadership is invaluable. After regrouping in the ruins, Sam discovers that he can perceive a symbol field, at first with pain and difficulty and then increasing facility, which will allow him to control the planet's technology. In the mountains nearby, he can also get crucial guidance from the Sentience, a kind of wise computer. A ruthless Earth conspiracy at the highest reaches wants to use Sam to exploit the planet's rich resources—but with help from the Sentience, his friends, and the resistance movement, Sam might pull off a dangerous bid to return to Earth and beard the all-powerful Tricium lion in his den. In his well-written novel, Flanagan tells an appealing story of the seemingly small and weak standing up to overwhelming forces. Though technology is in some ways at the center of the tale, the author takes care to underscore the human element, as in the tender relationship between Sam and his sister, Kara. Similarly, the attraction between Sam and Rebecca isn't perfunctory or simply a matter of physical attraction but based on the qualities they've displayed. When Sam tells her, "I think the person you are is amazing," it's believable and touching. The extraterrestrial civilization seems truly—and captivatingly—alien, not just familiar elements in exotic dress. Flanagan does a fine job of establishing what's at stake by first showing the dreary futility of life for most on Earth, a plausible haves/have-nots setup with resonance for readers today given widening wealth inequality. The plot is well-orchestrated, with several tense battle scenes, some surprises, and a growing sense of urgency as the narrative progresses that leads to a taut, deftly described, complex, and cinematic action sequence. The ending is well-judged, with an outcome that leaves room to grow. Exciting, heart-pounding action; genuine motivations; and vivid writing make this a compellingly entertaining coming-of-age tale.