Grade school teacher and aspiring author Peregrine Long sees a Chinese family on board a ship--in his morning tea. The image inspires him to write the story of this family, but then a woman turns up at his door, claiming that he's writing her family history exactly as it happened. She doesn't like it, but she has one question: What happened to the little boy of the family, her long-lost uncle?

Throughout the course of a month-long tempest that begins to wash the peninsula out from beneath them, Peregrine searches modern-day San Francisco and its surroundings--and, through his continued...