It is the twins’ final term as first formers at their now well loved boarding school St. Clare’s. All ready to join Miss Jenks in the second form, they are dismayed to find out they are to be in quarantine first for the mumps. When found they do not have it, they set off for a very adventrous term. 

          The new girls are different than ones they’ve seen – Bobby (or Roberta, as that is her given name) is a tomboy who plays tricks and lies back, possibly wishing never to do a lick of work, Carlotta hides a secret, a big secret at this, and Prudence tries to be pious and gentle but it is easy to see she is anything but. Pam Boardman is also a new girl who is younger – the form is fourteen but she is thirteen and very, very smart. She often is top in class and Doris remains at the bottom as always. Yet then there is Sadie. Alison worships the American girl who to the form’s dismay cannot pronounce words except in an American drawl. She is rich and fancy; something Alison easily worships.