In 1848, ten-year-old Toozak, a Yupik Eskimo, sees a whalebeing born and is told by a shaman that he and his descendants must protect that whale, which Toozak names Siku, for as long as it lives.
Jack and Benny are having a hard time reading "The Hidden History of Chowder Bay," given to them by Captain Hollister, but when a spooky whaling ship appears in the bay, the boys abandon the tome and join the search for Caldera, the fiercest whale that ever lived.
Enthralled by her grandmother's story of seeing and hearing whales singing in the sea long ago, Lilly hopes to see them herself and to hear their mysterious songs.
Discusses the evolution, biology, habits, and behavior of whales, dolphins, and porpoises, identifies the differences between them, and includes information about how the creatures are portrayed in art, myth, and legend.