Death of the Witch

A woman found dead on a witch's pillory. A sister distraught and claiming multiple murders. Can Siobhan expose the secrets of a female society to the light in order to bring a killer to justice?
When a woman is found dead on an ancient witch's pillory in Carrickfergus, her sister petitions Siobhan to help bring the guilty to light. But when the dead woman is found to belong to an order long forgotten, she is forced to enlist to learn the secrets of the cult. Can Siobhan keep mind and soul together to bring home the first case of her fledgling detective enterprise?
Hubble, bubble, toil and so much trouble!