An eight-year-old boy goes to live with his Norwegian grandmother after his parents are killed in a car crash. The grandmother is a wonderful story teller. He loved all the stories, but he was enthralled by the ones about witches, which she says are horrific creatures who seek to kill human children. She tells the boy that she knows of five children who were cursed by witches and tells him how to recognise them. She had an encounter with the witches, where she lost her thumb. While witches look and act like human women, they are actually "demons in human shape." They have bald heads that they hide with wigs, clawed hands that they usually hide with gloves and toeless feet that make it extremely painful to wear pretty shoes.
Per the parents' will, the boy and his grandmother have to return to England, where he was born and was in school, and where the house he is inheriting is located. The grandmother warns the boy to be on his guard, however, since English witches are known to be among the cruelest in the world. They are particularly notorious for turning children into loathsome creatures so that unsuspecting adults kill them. As the boy asks more questions, the grandmother reveals that witches in different countries have different customs; and that while the witches in each country have close affiliations with one another, they are not allowed to communicate with witches from other countries. She warns him to beware of the Grand High Witch, the feared and diabolical leader of all of the world's witches, who each year visits their councils in every country.