ALA Booklist (Mon Apr 01 00:00:00 CDT 2019)

This follow-up to The Flooded Earth (2018) continues Will and Annalie's quest to find their father, Spinner, who remains in hiding from the Admiralty. Along with new friends Essie and Poe, the twins set sail, using the clues Spinner left behind to search for his old colleagues. Wherever they go, however, the Admiralty is one step ahead. When a massive storm separates the young crew, Annalie and Poe must contend with pirates, while Will and Essie are swept out to sea, left to fight for their survival. This separation allows for the characters to develop in new ways, forming fresh dynamics among them. Themes of friendship and family anchor the story as the children bond and danger increases. As in the first book, this sequel offers commentary on the refugee crisis, often using humor to alleviate the tense material, but McConnochie also delivers higher stakes, daring escapes, wild storms, and pirate battles in a second adventure sure to please young thrill-seekers.

Horn Book (Thu Aug 01 00:00:00 CDT 2019)

This equally fast-paced, action-driven sequel to The Flooded Earth begins with a storm at sea, three weeks after twins Will and Annalie and their friends escaped Little Lang Lang Island. McConnochie expands the setting of her post-Flood world--sending the characters to distant lands and introducing new cultures as they continue to search for the twins' father--while also exploring the scientific and ethical challenges of climate-altering technology.

Kirkus Reviews

Will and Annalie continue the search for their dad in the middle installment of an Australian eco-thriller trilogy (The Flooded Earth, 2018).Ever since their father, Spinner, disappeared, the 12-year-old twins have been seeking him out on the ocean. Society is rebuilding since the Flood that broke the planet (not quite our world but one that's overwhelmingly familiar), but it still seems torn between the despotic Admiralty on the one side and criminal pirates and gangs on the other. Out on the Sunfish, Will and Annalie have nobody but each other and their dearest friends: rich girl Essie, undocumented former slave Pod, and Spinner's cybernetically enhanced parrot, Graham. While they quest for Spinner and his research into geo-engineering the Flood, the children avoid the wicked forces of the Admiralty and survive all manner of adventures: a storm at sea, stranding on a deserted island, capture by pirates, arrest by immigration officers, and having to eat some pretty gross bugs. The eponymous castle in the sea plays a startlingly small role but leaves unanswered questions, hopefully to be addressed in the conclusion. The perils are all excitingly perilous, but they are also relatively nonterrifying; in a dark and malicious world, the levels of danger feel more exciting than dreadful. The characters are racially ambiguous, with names and origin stories that imply some diversity of background.A post-apocalyptic disaster story with the cozy feel of Swallows and Amazons. (Science fiction. 10-12)

School Library Journal (Wed May 01 00:00:00 CDT 2019)

Gr 4-6 In this sequel, twins Annalie and Will, along with their friends Pod and Essie and talking parrot Graham, are sailing on the high seas in search of Spinner, the twins' father. On their tail is the Admiralty, who is also looking for Spinner. The children are tracking down scientists who worked with the man in the hopes that they will not only lead them to Spinner but will also provide them with information about the research he stole from the Admiralty. When a storm hits, Will and Essie become separated from the others after they are thrown overboard. Continuing on their mission while also searching for Will and Essie, Annalie and Pod find themselves on Dasto Puri, home to dangerous pirates. As the story progresses, more is revealed about the great flood. Spinner's former team continues to be split about whether to use the technology again in order to reverse the flood's effects. When the children finally catch up to Spinner, he must take leave once again. Readers will be engrossed in this action-packed adventure story and will eagerly await the next installment. VERDICT A satisfying, high-stakes sequel. Recommended for middle grade collections that own the first novel. Marissa Lieberman, East Orange Public Library, NJ