Instead of spending her golden years lying down, the indomitable Hetty Wainthropp found her calling late in life. Combining common sense, her husband, and her pocketbook, this senior sleuth takes on all the cases the police deem too minor.

During a visit to childhood friend Edith, retired housewife Hetty Wainthropp discovers that Edith's husband, Frank, has a son by a previous marriage. Hetty decides to turn amateur detective to trace him. When this gives her a taste for detection, Hetty decides to set up a private detective agency.

The activities of the staff at The Junior Gazette, a children's weekly newspaper produced by a group of school pupils.