Bespectacled Henry, a seriousminded, physically active teen-ager, is sensible but still fun-loving. He wants to become a naturalist, or maybe an artist, but he experiments with different approaches to making a living. He sets up Henry Reed, Inc., a research firm fashioned after those in the nearby university town, in an old barn.

Midge Glass, the daughter of a research chemist and, at twelve years old, the only person close to Henry's age in Grover's Corner, soon joins him. An active, skinny girl with a freckled face and hair pulled back into a practical ponytail, Midge is a sharp businesswoman. She is somewhat odd but smart enough to make a good summer companion. She becomes Henry's guide to the neighborhood and adds a practical view to their ideas. Accompanied by Henry's adopted beagle, Agony, Henry and Midge set out to make some money from...