Cussy Mary Carter is the last of her kind, her skin the color of a blue damselfly in these dusty hills. But that doesn't mean she's got nothing to offer. As a member of the Pack Horse Library Project, Cussy delivers books to the hill folk of Troublesome, hoping to spread learning in these desperate times. But not everyone is so keen on Cussy's family or the Library Project, and the hardscrabble Kentuckians are quick to blame a Blue for any trouble in their small town.