Carman continues the story he began in Atherton: The House of Power (2007), depicting a world created scientifically as an alternative to its ecologically failing parent planet. The sequel completes the violent metamorphosis that provided a dramatic climax for the first book. A verbal sketch of the world and a list of characters precedes the narrative, bringing series readers up to speed and allowing new readers to dive directly into the story. The fast-paced and suspenseful plot takes place on the planetoid’s surface as well as in its bowels. In alternating narratives, readers follow the adventures of both the population above ground (who wrestle with massive environmental disaster) and the small group of key characters, which includes Samuel and Isobel, two of the three child heroes, who struggle to escape before the world’s environmental transition traps them below. There’s a lot to like in this science-fiction adventure—danger abounds, science seems to have run amok and a neat (but not too neat) ending ties up most of the loose ends. (Science fiction. 9-12)