“Alex saw very clearly how dangerous a book like Mary’s could become in the hands of such impressionable girls, such privileged girls: girls who kissed and fondled and laughed as they read each other passages out in the woods; girls whose parents' social standing had taught them that there was nothing at all in the world they could not subjugate, purchase, or ignore; girls who set fires only to watch as others tried, and failed, to put them out.”