The story takes place in the late 17th century and the mid 18th century. Its main characters are a powerful landowner named Sir Matthew Fell and his grandson Sir Richard Fell. In the year 1690, a woman known as Mrs. Mothersole is found guilty of being a witch and condemned to death, largely on the strength of testimony given by Sir Matthew Fell. Shortly afterwards, Sir Matthew dies in mysterious and horrific circumstances. Some fifty years later, Sir Richard inherits his grandfather's former home. He finds that an ash tree in the grounds of the house is causing him problems.