The Witches is the book about proper witches and the tale of a boy who encounters them.
A young boy (name was not in the book) goes to stay with his grandmother in Norway after his parents are killed in a car accident. There, she tells him stories about witches, demons who look and act like women that are on a mission to destroy children. She tells him that when she was a child, five of her friends by witches. It is also implied she herself encountered a witch, as her thumb is missing.
The next day, she tells him about how to spot a witch, and also tells him of the Grand High Witch Of All The World, the tyrannical ruler of the witches who goes from country to country to hold a special meeting with the witches of that country. On the boy's deceased parents will, he and his grandma move back to England. Not long after this, the boy is building a tree house when a strange woman wearing gloves (witches wear gloves to hide their clawed fingers) arrives and tries to persuade the boy into coming down the tree with a snake. The boy, realizing she is a witch, climbs up into the tree and stays there for hours until his grandma calls him back. Upon hearing of his encounter with the witch, she tells him that he is not going to school alone.
The boy's grandma gets diagnosed with pneumonia, forcing them to cancel their holiday trip to Norway. Instead, they go to a hotel in Bournemouth. The boy trains his pet mice William and Mary in the hotel ballroom, believing he has nothing to fear as the RSPCC (Royal Society for the Prevention of the Cruelty to Children) are holding a meeting there.
The woman of the RSPCC came in, and the boy hides. However, he notices one woman reach under her hair and scratch her head (witches are bald so they wear wigs), and the boy realizes that the RSPCC are really a convention of witches. A woman comes up on stage and the boy realizes she is the Grand High Witch his grandma told him about. The Grand High Witch allows the witches to reveal their true forms, with the Grand High Witch taking off her mask to reveal a hideously deformed face.
The Grand High Witch scolds the witches of England for not doing away with most of the children, and when she orders that every child be destroyed, a witch scoffs silently, but the Grand High Witch overhears and fries the witch, terrifying the others. The Grand High Witch then reveals her plan to destroy all the children: she has created a formula that turns anyone who consumes it into a mouse. She plans to have the witches open up candy stores and put the formula in the candies and when the children eat the candy they will transform into mice when they go to school tomorrow. The Grand High Witch demonstrates this with a rich boy named Bruno Jenkins, who she had fed a contaminated bar to earlier. At precisley 6:15, Bruno turns into a mouse. The witches are about to leave when one witch, Mildred, smells the boy, forcing him to make a break for it before they can corner him.
The witches chase the boy, hellbent on eliminating someone who has spied on their affairs. The boy manages to escape onto a beach, after saving a baby pushed in it's stroller by the Grand High Witch in an attempt to lure him into a trap. The boy makes it to Grandma, who appears to have fallen unconcious due to the diabetes, only to be found by the witches who capture and bring him to the Grand High Witch, who pours an entire bottle into the boy's mouth. He transforms into a mouse and runs off before the witches can dispose of him. The boy finds out that, miraculously, the witches only changed him in appearence and he can talk. He finds Bruno and the two run off to find the boy's grandma. They are nearly caught by the hotel's maid but the grandma is able to hide them. The grandma starts crying over her grandson's transofrmation, but the boy tells her not to worry, as he is not really upset.
The boy and his grandma find out that the Grand High Witch's room is right under theirs, so the grandma lowers the boy onto the Grand High Witch's balcony, intending on taking one of the bottles of the formula. He finds the bottles, as well as coming across three frogs who were once children until the Grand High Witch got them. He takes one bottle but before he can escape the Grand High Witch comes and closes the balcony. However, he escapes when some old witches come to recieve the formula so they can keep up with younger counterparts.
With the bottle, he reaches his grandma and makes plans to transform the witches into mice by putting the formula in their food. First, his grandma tries to warn Bruno's parents, but when she shows them Bruno, his mothers freaks out, as she has a fear of mice, and his father drives them off. The boy then sneaks into the kitchen and pours the bottle into the witches food. He then escapes while having the tip of his tail chopped off.
Mr. Jenkins confronts the boy's grandma to ask them where Bruno is. Bruno then talks, surprising his father. The grandma then reveals that the Grand High Witch did it, to which Mr. Jenkins stomps off to confront her. However, before he can walk more than a few paces towards the witch leader, all the witches start turning into mice from consuming the formula, including the Grand High Witch, and they are promptly disposed of.
When they get back to their house, Luke is still a mouse but says that he is ok with it. But one of the "good" witches comes outside their house and uses her magic to make him back to a human.
Luke Eveshim (named in film), the main character and a boy who is transformed into a mouse by witches.
Helga Eveshim (named in film), the deuteragonist and Luke's grandma.
Bruno Jenkins, the tritagonist and a boy who is, along with Luke, transformed into a mouse
Eva Ernst (named in film), the Grand High Witch, ruler of the witches and the main antagonist.
Mr. Stringer, the hotel manager Mr. Jenkins, Bruno's father.
Mrs. Jenkins, Bruno's mother.
Woman in Black, a witch that Luke encounters under a tree. She is the first witch Luke encounters.
Beatrice (named in film), a witch that the Grand High Witch incinerates.
Mildred, the witch who smelled Luke.
Chambermaid, a minor antagonist who acts more like a snitch than a maid, trying to catch Luke with his two mice so that his pets will be drowned.
William, a waiter.