Betty and Sam, 9 year old friends, are given a project by their grumpy teacher Mrs. Broadchalk: WHAT MAKES US HUMAN BEINGS ? They begin to grapple with the challenge by observing nature all around them and conclude that animals do everything better than we humans. Downhearted, they seek help from Betty's uncle, Professor Humphrey Tanglewire, a retired inventor. His enthusiasm cheers them up, and he gives then a key word: "HANDS " and 12 questions to answer. Betty and Sam now enter upon a journey of exploration which brings then to observe and study