Sarah Engelhardt has spent a lifetime learning the ways of the cetaceans and the tales of Mother Ocean. But no university has any interest in granting her tenure so she might continue her research and her efforts to share what she's learned with the next generation. Worse, she's earned the enmity of the nations who see the cetaceans as food because she's told them killing the whales is the equivalent of murder. Only with great reluctance does she accept the invitation to attend a conference hosted by the Ark Society about how to preserve life on Earth against all the forces trying to destroy it. Much to her horror, she learns that a peanut-sized primordial black hole is about to pass through the Earth-Moon system, with drastic effects, and that only those living within the seven Arks built around the world have even the slightest hope of survival. With help from Davi Weisel, whom she must pull out of dreadful despair, as well as Leo Abramson, who invited her into the World Ark, and Angelwings, her dolphin mentor, she works to find a way for Mother Earth to communicate with the poor, lonely, lost humans who have nevertheless learned how to build the Arks so that all life within the Arks may survive the End of the Age.