On a day when everything goes wrong, a little girl relies on the magic of the blue moon to turn things around. Since her mother swam away seven years ago, ten-year-old Keeper has lived happily with Signe on a remote slice of Texas coast, convinced that her mother’s a mermaid. Keeper’s waited all summer for the blue moon, when Signe will make blue moon gumbo, their friend Dogie will propose to Signe and their elderly neighbor’s night-blooming cereus will flower. But when she accidentally spoils everything, Keeper sets out under the blue moon in a small boat, determined to row across dangerous Gulf waters to find her mother. While the action occurs in a single day, Appelt relies on flashbacks to flesh out her diverse human, animal and mythical characters. Deftly spinning together mermaid lore, local legend and natural history, this stunning tale proves “every landscape has its magical beings,” and the most unlikely ones can form a perfect family. Hall's black-and-white illustrations lend perspective and immediacy. Beautiful and evocative—an absolute “keeper.” (author’s note) (Fiction. 8-10)