Paris, 1885: Aubry Tourvel, a spoiled and stubborn nine-year-old girl, comes across a wooden puzzle ball on her walk home from school. She tosses it over the fence, only to find it in her backpack that evening. Days later, at the family dinner table, she starts to bleed to death. When medical treatment only makes her worse, she flees to the outskirts of the city, where she realizes that it is this very act of movement that keeps her alive. So begins her lifelong journey on the run from her condition, which won’t allow her to stay anywhere for longer than a few days or return to a place where she’s already been. But the longer Aubry wanders and the more desperate she is to share her life with others, the clearer it becomes that the world she travels through may not be quite the same as everyone else’s.