After an incident at the homecoming dance, sixteen-year-old Bisou Martel finds herself humiliated and running into the woods near her Seattle home. She is chased by a giant wolf, which she manages to kill, but not before suffering wounds herself. Later, it's found that a classmate was found dead in the woods with the exact wounds Bisou inflicted on the wolf. It's only then that her Mémé tells her about a family legacy tied to the moon and her menstrual cycle--a legacy of power that she will need to develop to face the waiting wolves.