Mrs. Jonathan (Elizabeth) Brisby, a very beautiful, shy and timid field mouse, lives in a cinder block with her children on the Fitzgibbons' farm. She is preparing to move her family out of the field they live in as plowing time approaches; however, her son Timothy has fallen ill. She visits . Mr. Ages, another mouse and old friend of her late husband, Jonathan, who diagnoses Timothy with pneumonia and provides her with some medicine from his laboratory. Mr. Ages warns her that Timothy cannot go outside for at least three weeks or he will die. On her way back home she encounters Jeremy, a clumsy but compassionate crow.
The next day spring plowing begins, and though Mrs. Brisby's neighbor is able to stop the tractor, Mrs. Brisby herself knows she must come up with another plan. With the help of Jeremy, she reluctantly visits the Great Owl, a wise creature living in the nearby woods, to ask for help. He tells her to visit a mysterious group of rats who live beneath a rose bush on the farm and ask for Nicodemus.
Mrs. Brisby goes to the rats' home, where she is amazed to see their use of electricity and other human technology, as they have taken on medieval. She meets Nicodemus, the wise and mystical leader of the rats, and Justin, a kind and friendly rat who is the Captain of the Guards, as well as a dark, ambitious rat named Jenner, who plans to kill Nicodemus in order to become a leader. She learns that her late husband, along with the rats and Mr. Ages, was a part of a series of experiments at a place known as N.I.M.H. (which stands for the National Institute of Mental Health). The experiments had boosted their intelligence to human level, allowing them to easily escape. However, the rats have concocted "The Plan", which is to leave the farm and live without stealing electricity from humans. Nicodemus then gives Mrs. Brisby a beautiful red amulet that gives magical power when its wearer is courageous.
Because of her husband's prior relationship with the rats, they agree to help Mrs. Brisby move her home out of the path of the plow. Mrs. Brisby volunteers to drug the Fitzgibbon's cat, Dragon so that they can complete the move safely. Only mice are small enough to fit through the mouse hole leading to the house, and Jonathan was killed by Dragon while trying. Later that night, she successfully puts the drug into the cat's food dish, but the Fitzgibbon's son Billy catches her and convinces his mother to let him keep her as a pet. While trapped in a birdcage, she overhears a telephone conversation between Mr. Fitzgibbon and NIMH and learns that NIMH intends to come to the farm to exterminate the rats the next day. She manages to escape from the cage and runs off to warn Justin.
Meanwhile, the rats are completing the move during a thunderstorm. However, Jenner and his hesitant accomplice Sullivan, who wish to remain in the rose bush, kill Nicodemus, making it look like an accident. Mrs. Brisby arrives and tries to convince the rats that NIMH is coming and that they must leave immediately. However, Jenner is angered by her claims and attacks her. Alerted to the situation by Sullivan, Justin rushes to Mrs. Brisby's aid; a sword fight between Justin and Jenner ensues, ending with a mortally wounded Sullivan killing Jenner by throwing his dagger right at Jenner's back and saving Justin's life, as Jenner fell into the mud below, to his death.
Though the duel was over, another disaster was just beginning: the block was sinking! Now it was Brisby's turn to save the day. She suddenly realizes that her children are still in the block after hearing their voices inside. Unfortunately, the block begins to sink in the mud it landed in. Despite the best efforts of the rats, they are unable to pull it from the sinkhole and Justin pulls Mrs. Brisby out from drowning in the mud. However, Mrs. Brisby's will to save her children gives power to the amulet, which she uses to lift the house out of the sinkhole and move it to safety from the plow. The next morning, the rats have already gone to Thorn Valley with Justin as their new leader and Timothy has begun to recover. Jeremy also eventually finds "Miss Right", an equally clumsy crow, and the two fly away together.
- Elizabeth Hartman as Mrs. Brisby, the main character and female lead
- Dom DeLuise as Jeremy, the deuteragonist
- Peter Strauss as Justin, the tritagonist and male lead
- Arthur Malet as Mr. Ages, an old mouse
- John Carradine as Great Owl
- Derek Jacobi as Nicodemus
- Paul Shenar as Jenner, the primary villain
- Aldo Ray as Sullivan the tertiary villain
- Tom Hatten as Farmer Paul Fitzgibbons, the quaternary villain
- Hermione Baddeley as Auntie Shrew, the Brisby children's babysitter and the quinary villain later anti-hero
- Shannen Doherty as Teresa Brisby
- Jodi Hicks as Cynthia Brisby
- Wil Wheaton as Martin Brisby
- Ian Fried as Timothy "Timmy" Brisby
- Lucille Bliss as Mrs. Beth Fitzgibbons
- Joshua Lawrence as Billy Fitzgibbons
- Edie McClurg as Miss Right
The Secret of NIMH: Original Soundtrack contains songs from the film written by Jerry Goldsmith, and performed by Paul H. Williams and Sally Stevens. It was released on July 2, 1982, on vinyl and audio cassette by the "That's Entertainment Records" label (through MCA Records) and re-released on March 3, 1995, on CD by Varese Sarabande with a rearranged track listing.
- "Main Title" (3:13)
- "Allergic Reaction/Athletic Type" (2:40)
- "Flying Dreams Lullaby" (3:45) - performed by Sally Stevens
- "The Tractor" (2:58)
- "The Sentry Reel/The Story of NIMH" (6:03)
- "Escape from NIMH/In Disguise" (4:58)
- "Flying Dreams" (3:21) - performed by Paul H. Williams
- "Step Inside My House" (4:40)
- "No Thanks" (2:01)
- "Moving Day" (7:57)
- "The House Rising" (4:33)
- "Flying High/End Title" (2:38)
The film garnered widespread critical acclaim for being one of the most vibrantly animated films of its time and has earned a 96% "Certified Fresh" approval rating on the Rotten Tomatoes website, with the site's critical consensus reading, "The Secret of NIMH is a dark, well-told tale that respects its young audience enough to not tone down its subject matter". The film has now gained a very popular cult following beyond its release, amongst the furry fandom, fans of animation, fans of Don Bluth, fans the original novel by Robert C. O'Brien and the sci-fi/fantasy genre alike and people like Doug Walker (aka, The Nostalgia Critic) who claim it to be one of their all-time favorite movies. Despite such a high level of praise from both critics and audiences alike, the film was only a moderate success at the box office, making $14,665,733 out of a roughly $7,000,000 budget, attributed to a combination of poor promotion, regionally-staggered release dates and competition from Disney's Tron, Jim Henson's The Dark Crystal, ITC Entertainment's The Last Unicorn and Steven Spielberg's blockbuster E.T. the Extra-Terrestrial.
- Despite having a G rating by the MPAA, the IMDb parents guide article of this film suggested PG For Sci-Fi/Fantasy Violence, Some Scary Images, and Brief Mild Language.
- Prior to the 2-disc MGM Family Fun Edition released in 2007 the film was never seen in it's original theatrical aspect ratio, but rather the negative widescreen ratio.
|The Secret of NIMH|
The Secret of NIMH 2: Timmy to the Rescue ("Bluthless" sequel)
Characters: Mrs. Brisby | The Great Owl | Jeremy | Nicodemus | Mr. Ages | Auntie Shrew | Justin | Jenner | Sullivan | Teresa Brisby | Cynthia Brisby | Martin Brisby | Timothy Brisby | Brutus | Jonathan Brisby | Farmer Paul Fitzgibbons | Mrs. Beth Fitzgibbons | Billy Fitzgibbons | Dragon | Miss Right | Jenny McBride | Cecil | Joseph Valentine | Muriel & Floyd