Most girls in Gopher Slough, Florida, worry about whether GSHS will win the next football game (they won't), when their boyfriends will take them muddin', and how many times they can sneak cigarettes behind the bleachers before they get thrown into in-school suspension.
Libby Hoyer is not most girls.
Instead, Libby is worried about her slipping grades, especially in Geometry, where she can barely keep her head up long enough to take the weekly quizzes. She's concerned about losing her friendship with her best (only) friend, Bobbi Jo, who's distracted with her own Aber-zombie boyfriend, and she's unsure of how to define her new relationship with Neil, a mysterious boy from her class who is not as carefree as he pretends to be. Libby is also troubled by the fact that she can't seem to remember her distant father, even though he only left five years ago.
Everyone else, it seems, is worried about Libby's sporadic eating habits. If she continues to refuse to eat or to purge anything she's forced to eat, she might disappear. But Libby isn't afraid of disappearing. She's afraid of being seen.