Adventure abounds as the Alden children spend a summer living on their grandfathers island. They display a wealth of confidence in their ability to face lifes everyday challenges armed only with their clever inventiveness and the support of eachother. Few subjects are as sure to capture the imaginations of children as the idea of living on their own. A hint of suspense is woven through the story until the mysterious true identity of Joe the handyman is finally revealed.
The children are spending the summer on their own private island but there is a mysterious stranger on the island.