Rosemary is quite an ordinary schoolgirl who buys a broom one day and, for three extra farthings, a cat A good cat is apt to be independent, so she does not have things all her own way, and as Carbonel proves to be a Royal cat in a very special sense, that is understandable Between the two of them Rosemary picks up some useful spells and magic the long holiday at home that looks so dull turns into one long to be remembered