In an impoverished peasant family, a little girl called Hélène Jégado grows up in isolation, unloved, battered by the hardships of life and cradled by a morbid imagination.
Convinced she must serve Ankou, the spirit of Death in local mythology, Hélène poisons and kills her mother. For the rest of her life, she will travel the length and breadth of Brittany in search of her next victim, finding work as a cook and spreading death on her way.
She would become one of the biggest serial killers in history. To this day, no one could understand her motives or pierce her mystery.