Mrs. Frisby lost her husband the previous summer, but she has been able with "luck and hard work to keep her family . . . happy and well fed." While three of her children are indeed healthy and happy, the story begins as her son Timothy catches pneumonia. Moving Day, when all the animals must leave the field before plowing begins, is rapidly approaching, but if Timothy goes with them to the woods, he may die of exposure. Mrs. Frisby is determined to find a way to keep Timothy safe and warm until he can recuperate. This determination and love for her family leads her into subsequent adventures. Although she wishes her husband were there to help solve their problems, she knows that she alone is responsible for her family's welfare.

Mrs. Frisby is a practical, perceptive character, who does not dwell on her own worries, but...