"All children have imaginary friends, Georgina tells herself. It's perfectly normal, and they all grow out of it in the end. But when her seven-year-old son Cody tells her about New Granny, the new friend he's met in the park, Georgina is instantly suspicious. Something--call it maternal instinct--tells her he isn't making it up. But maybe Georgina is losing her mind. It wouldn't be the first time, after all"--