Lib Wright, a young English nurse, arrives in an impoverished Irish village on a strange mission. Eleven-year-old Anna O'Donnell is said to have eaten nothing for months but appears to be thriving miraculously. Lib's job is simple: to watch the girl and uncover the truth.
An educated sceptic, Lib expects to expose the fast as a hoax right away. But as she gets to know the girl she becomes more and more unsure. Is Anna a fraud, or a 'living wonder'? Or is something more sinister unfolding right before Lib's eyes?