It's 1870, and a young woman named Odile is fighting to survive on the blood-soaked streets of Paris. Luckily, Odile has an advantage and a bizarre birthright. She is descended from the Cagots, a much-despised race whose women were reputed to be witches. Were they, in fact? This is the question Odile must answer—about her ancestors and herself—while she uses her talents to help a young Doctor Jekyll who seems to be abusing the salts that she gave him in a most disconcerting way.