The Sharp children live in Cleve Cottage at the end of Cleve Road. Lizzie, the eldest is thirteen, Dan is ten, and Max is seven. When their only neighbors, the ancient Potwards, complain and ruin her birthday party, Lizzie decides to become a witch and cast a spell on them. Max is so lonely that he has an imaginary family, the Dumplings, as friends. When Lizzie agrees to let him be the "Witch's Assistant," he is ecstatic to be playing with his sister instead of the Dumplings. Meanwhile, Dan is standing around making sarcastic remarks about there being no such thing as magic - until the spell works.

With coincidences piling up on top of spells, Lizzie begins to believe in her own power, Dan becomes uneasy, and Max is absolutely positive that Lizzie can work magic and that magic runs in the family. This book is a wonderful combination - ludicrously funny and touching.