Katie is a third grader who lived happily with her pretty mother and doting father. When suddenly she finds herself an orphan, her life is turned upside down. The social worker discovers that she has one living relative, her mother’s older sister. This puzzles Katie as she has never heard of having an aunt. She is taken to live with this strange aunt who lives in the hilly, backwoods of a little country town. The aunt is surly and even cruel at times. She seldom talks except to demand overwhelming tasks from Katie.
Katie finds peace in the beautiful woods and makes friends with the animals. Her special friend is a fish, who she feels listens to her plight with sympathy. One day, he turns Katie into a fish, and they go off on an adventure to solve the problem of her mean aunt.