Mrs. Frisby is the head of a family of field mice that lives in a cinder block, which “lay on its side in such a way that the solid parts of the block formed a roof and a floor, both waterproof, and the hollows made two spacious rooms” (2). The cinderblock is almost completely buried underground in the vegetable garden of Mr. Fitzgibbon. A mouse-sized tunnel leads out of the mouse house and into the garden. It also provides light. The living room and bedroom, the home’s two rooms, are connected by another tunnel. With the linings the mice collect, the house stays warm all winter. Mrs. Frisby’s husband died the summer before (he was eaten by Dragon, the farm cat), but she has so far managed to keep her four children—Teresa, the eldest; Martin, the biggest; Cynthia, pretty and slim; and Timothy, the youngest— alive through the harsh winter, until Timothy becomes ill.

The morning that Timothy’s sickness begins, Mrs. Frisby awakes as usual. She laments the family’s lack of fresh food in the winter, then crawls outside to find a scrap of anything that might change up their usual winter foods. The ground is covered in frost, but she comes across a seemingly abandoned storage of corn, nuts, and other foods inside a tree stump.