Pauline, Petrova and Posy are found as orphaned babies in different parts of the world by eccentric fossil collector and explorer Great-Uncle Matthew - 'Gum'. He adopts them, takes them to his London home and leaves them in the care of his niece Sylvia and the family Nurse. Then off he goes. At first they lead privileged and sheltered lives, but when Gum fails to return after five years, the money begins to run out and then everyone has to do something to make some more. How the three girls help is a heart-warming tale that has made this book a bestseller since it first publication.