Writer and filmmaker Julia Whitty will make even the most landlocked among us feel that we have been privy to the mystery and wonder of the undersea world. In The Fragile Edge (Houghton Mifflin), she takes us diving near three exquisitely beautiful and seriously endangered Polynesian islands. First, the shark-rich waters of Rangiroa, the second-largest atoll on earth, enclosing a nearly 400-square-mile lagoon within a 140-mile bracelet of islets. There she meets a blue-spotted cornetfish that drifts by, "as long and narrow as a section of PVC pipe, staggeringly unfishlike. It travels in the manner of its species, vertically, head down, large eyes circling around at me, not alarmed but likewise interested. We study each other. Suddenly it blushes." Next, to Funafuti, which is in danger of vanishing due to rising sea levels—and finally to Mo'orea, an atoll in the making, where a female argonaut octopus invites her tiny mate into the shell she made herself, and a pod of spinner dolphins perform their joyful, synchronized acrobatics before giving their lives to a lemon shark, their bones falling to become part of the reef. The product of a scientist's mind, a sociologist's eye, a Zen Buddhist's soul, and a poet's heart, The Fragile Edge is at once a natural history, a call to action, a love song, and a prayer.