Fourth-graders Drake Doyle and Nell Fossey combine their detective and scientific investigation skills to solve a variety of cases, involving a noisy garbage can, endangered frogs, a stuck truck, and a mysterious love letter. Includes a section of scientific experiments and activities.

Fifth graders Drake Doyle and Nell Fossey use their detective and scientific investigation skills to solve cases which involve food poisoning, missing terns, a haunted treehouse, and a pig in a pit.