Lewis's scientist father has long been discredited for his theory that inhabitants of the underwater city Atlantis have been sending tsunamis to destroy American coasts, an Atlantean retaliation for the pollution of the ocean. When one of the tsunamis carries father and son, along with talented engineer Hanna, far undersea in their subsphere vehicle, they learn that the theory was absolutely right. Meanwhile Kaya, an Atlantean, has always been told that there are no "People of the Sun" dwelling near ocean surfaces: to suggest otherwise is treason. When Kaya encounters the three from the surface, she knows they're doomed if she doesn't help them evade Atlantis's surveillance squad, the "Erasers." This steampunkish sci-fi/fantasy adventure is quickly paced, an inventive, if far-fetched, engagement of plastics pollution and climate change -- as well as a diverting vision of Atlantis's underwater technology. Lewis's middle-grade wackiness is quietly funny and realistic; he is blinkered by his own cultural formation but is a fount of imaginative diversions. With the book's conclusion perched on the eve of the travelers' return, Mone seems to be promising a sequel. An afterword discusses Atlantis's lore and the current crisis of plastics pollution in Earth's oceans. Deirdre F. Baker

Two strangers from different worlds must stop a shadow war.Twelve-year-old Meriwether Lewis Gates' futuristic life might be recognizable in some ways, but it's also plagued by unrelenting, destructive tsunamis. His dad is an eccentric and brilliant academic whose insistence on Atlantis' existence has left him all but ostracized from the scientific community save for his genius teenage assistant, Hanna. Meanwhile, fathoms below in her Atlantean home of Ridge City, 14-year-old Kaya lives with her father and grandmother and is fascinated by illicit stories about the People of the Sun who live above on dry land. When Lewis' and Kaya's worlds collide, they (along with Hanna and Lewis' dad) form an unlikely alliance, discovering that as climate change and pollution poison the sea, Atlantis is quietly and violently retaliating. The Erasers, a secret Atlantean faction, seek to silence and quell anything to do with the People of the Sun. Can these new friends save both Atlantis and Earth? Written from both Kaya's and Lewis' third-person points of view, Mone's book features expeditious pacing, ample secrets, and imaginative science and tech creations that are zippy indeed, though some points are resolved too conveniently. In a jaunty Q&A, Mone carefully explains how he conceived his innovations and their scientific inner workings. Also provided are tips for making a difference regarding ocean pollution. Lewis is presumably White; Hanna is cued as Black.This fun adventure both engages and gently edifies. (map) (Science fiction. 8-12)