"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. And with her own mother's recent death...