Mrs. Frisby and the Rats of NIMH

Plot summary

Mrs. Frisby is the head of a family of field mice. Mrs. Frisby's son, Timothy, is ill with pneumonia just as the farmer Mr. Fitzgibbon begins preparation for spring plowing in the garden where the Frisby family lives. Normally she would move her family, but Timothy would not survive the cold trip to their summer home. Mrs. Frisby obtains medicine from her friend Mr. Ages, an older white mouse. On the return journey, she saves the life of Jeremy, a young crow, from Dragon, the farmer's cat - the same cat who had killed her husband, Jonathan. Jeremy suggests she seek help in moving Timothy from an owl who dwells in the forest. Jeremy flies Mrs. Frisby to the owl's tree, but the owl says he can't help until he finds out that she is the widow of Jonathan Frisby. He suggests that Mrs. Frisby seek help from the rats who live in a rosebush near her.

Mrs. Frisby discovers the rats have a literate and mechanized society. They have technology such as elevators, have tapped the electricity grid to provide lighting and heating, and have acquired other human skills, such as storing food for the winter. Their leader, Nicodemus, tells Mrs. Frisby of the rats' capture by scientists working for a laboratory located at the National Institute of Mental Health (NIMH) and the subsequent experiments that the humans performed on the rats, which increased the rats' intelligence to the point of being able to read, write, and operate complicated machines, as well as enhancing their longevity and strength. This increased intelligence and strength allowed them to escape from the NIMH laboratories and migrate to their present location. Jonathan Frisby and Mr. Ages were the only two survivors of a group of eight mice who had been part of the experiments at NIMH, and made the rats' escape possible. Out of respect for Jonathan, the rats agree to move Mrs. Frisby's house to a location safe from the plow.

Nicodemus also tells Mrs. Frisby about "The Plan", which is to abandon their lifestyle of dependence on humans, which some rats regard as theft, for a new, independent farming colony. One rat, Jenner, disagreed vehemently with The Plan and left the colony with a group of followers at some point prior to Mrs. Frisby's arrival.

To move the Frisby home, the rats have to drug Dragon as it is too dangerous to work in the open without any place to hide. However, Mr. Ages has a broken leg and cannot dash to Dragon's bowl to put in the drug. Since the other rats are too big to fit into the hole in the wall to enter the house, Mrs. Frisby volunteers to go. Unfortunately, she is caught by the family's son, Billy, who puts her in a cage. While captured, Mrs. Frisby overhears the Fitzgibbons discussing an incident at a nearby hardware store in which a group of rats were electrocuted after seemingly attempting to steal a small motor. This has attracted the attention of a group of men (who never identify themselves) who have offered to exterminate the rat colony on Fitzgibbon's land free of charge for him.

At night, Justin (one of the rats) comes to save Mrs. Frisby and manages to get her out of the cage. Mrs. Frisby warns Justin of what she learned while captured; they assume that the rats at the hardware store were all from Jenner's group and that the group of men were from NIMH and are looking for them specifically.

The successful house move allows the mouse family to remain while Timothy recovers before moving to their summer home. Although the rats have not yet had time to move everything they needed for The Plan, they manage to destroy their underground rooms, and create the illusion that they are just regular rats by placing rubbish in the remaining rooms. As the others move, ten rats stay behind so the exterminators would not think the rat hole has been abandoned. When the exterminators fill the rat hole with poisonous gas, eight of the ten rats manage to escape, while two rats die in the hole. It is not revealed exactly who these two are.

Once Timothy recovers, Mrs. Frisby and her family move to their summer home, and Martin makes plans to visit the rats when they return to their winter home again.

Related works

O'Brien's daughter, Jane Leslie Conly, wrote two other novels based on the rats of NIMH. Racso and the Rats of NIMH tells the story of a city rat who runs away to join the new colony, befriending Timothy, while saving the colony from a flood along the way. In R-T, Margaret, and the Rats of NIMH, the rats rescue two lost human children who in turn help to save the colony before winter.

Adaptations

In 1982, the animated film The Secret of NIMH was released, directed by Don Bluth. The film adds a mystical element completely absent from the novel, with Nicodemus portrayed as a wise, bearded old wizard with magic powers and an enchanted amulet, rather than an equal of the other rats. The character of Jenner is made a villain who is still present with the rats, rather than having left them before the story begins. The crow Jeremy receives much greater prominence as comic relief in the film than he has in the book. Additionally, the Frisby family name was changed to "Brisby" to avoid trademark infringement with the Frisbee.

In July 2009, Paramount Pictures set Neil Burger to write the script and Cary Granat to produce the film based on the book.

On March 4, 2015, MGM, which released the 1982 film, acquired the rights to the book to adapt it into the live-action/animated film, set Michael Berg to adapt it, while Daniel Bobker and Ehren Kruger would produce.

Parallels in science

Research published in the March 2013 issue of Cell Stem Cell details the injection of human glial cells into the brains of newborn mice. Upon maturation, the mice were faster learners.