A village in 1850s Ireland is baffled by Anna O'Donnell's fast. A little girl appears to be thriving after months without food, and the story of this "wonder" has reached fever pitch. Tourists flock in droves to the O'Donnell family's modest cabin, and an international journalist is sent to cover the sensational story. Enter Lib, an English nurse trained by Florence Nightingale, who is hired to keep watch for two weeks and determine whether or not Anna is a fraud. As Anna deteriorates, Lib finds herself responsible not just for the care of a child, but for getting to the root of why the child may actually be the victim of murder in slow motion.