As a child, Alexia suffers a terrible car accident and has a titanium plate fitted into her head. As she grows up, the effects of the trauma follow her throughout life; she becomes increasingly unhinged and commits a series of violent acts before going on the run from the police. To hide, she assumes the identity of the long-missing son of a French fire chief, Vincent, and a strange bond develops between them as both struggle with loneliness and emotional damage.