Mrs. Frisby and the Rats of NIMH by Robert C. O’Brien
Mrs. Frisby’s son, Timothy, is ill and cannot be moved. But it is time for the family to move. It is time for farmers to start planting their crops and, to do so, they must first till up the land, including the spot where Mrs. Frisby’s house is located. Mrs. Frisby consults a wise owl who introduces her to a brilliant tribe of rats. The rats, Mrs. Frisby learns, are friends of her late husband. She hears their fascinating story and the rats are able to come up with a way to save Timothy and Mrs. Frisby’s home.