The danger-riddled adventures continue for polar bear cubs Stellan, Jytte, Third, and Froya in this third Bears of the Ice series installment. Upon delivering the Ice Clock key to the owls of the Great Ga'Hoole Tree, the birds realize war within the kingdom is imminent. The owls share their wisdom with the young bears and send them to solicit help from other owl and wolf clans. Meanwhile, Stellan and Jytte's mother, Svenna, has escaped the Ice Clock, distressingly witnessed her cubs' father Svern disappear into an ice fissure, and begun the trek toward the Great Ga'Hoole Tree. Will the bear family be reunited? Will the impending war with Patek finally destroy him and the Ice Clock? Lasky brilliantly entwines characters from her other series into this creative fantasy world, and her imaginative writing will make readers willingly suspend reality and trust the mental acuity of her animal characters. Although supposedly the final book in this series, the story contains several unanswered questions that beg for another installment.--J. B. Petty Copyright 2019 Booklist