Newly widowed mouse Mrs. Brisby tries to take care of her four offspring under a stone in the fields of Farmer Fitzgibbons, though she almost loses the medicine for Timothy (ill with pneumonia) in a chase with the farmer's evil cat, Dragon. The medicine is salvaged by Jeremy, a friendly if clumsy crow eager for a partner in life. Auntie Shrew warns that 'Moving Day' is near, and a tractor soon ploughs up the field, though Timothy is confined to his bed and cannot be moved. The fearsome Great Owl advises Mrs. Brisby to seek the help of Nicodemus, king of the rat colony in Farmer Fitzgibbons' rosebush. The rats, who hold Mrs. Brisby's late husband Jonathan in mysterious respect, vote to help move her home to safety, despite initial protests from the villainous Jenner. Jonathan, it is revealed, was a fellow prisoner at the National Institute of Mental Health and helped the rats (made extra intelligent by drug treatment) escape to their present home. Nicodemus, however, is now urging a move to Thorn Valley, which would enable them to live without poaching the farmer's electricity supplies; once again, Jenner opposes the idea. Taking advantage of the turmoil during the removal of Mrs. Brisby's home, Jenner arranges Nicodemus' 'accidental' death, though he himself is killed before he can attack Justin, the trusty Captain of the Guard. Mrs. Brisby's home sinks into the mud, but is raised by a magic amulet. The rats settle in Thorn Valley, Jeremy finds a companion crow, and the Brisby family finds peace.
A gnarled stump of candle, cobwebs, a trail of sparkle from a quill pen: the opening images immediately define (and limit) the animation style in this first feature masterminded by the rebel artists who left Disney after a dispute over standards in 1979. Their mission to safeguard traditional Disney values extends much further than the romantic story-book style of backgrounds and inanimate objects, the rivival of multiplane camerawork, the reintroduction of characters' shadows. Mrs. Brisby's household is Disney's nuclear family: small, furry, cuddly and cute, with adorably large eyes. Sentiments, too, are impeccable, even though their application is a trifle bizarre: homilies against men tampering with rats' biological make-up; homilies against rats tampering with man's electricity; a vocal summons to "Trust Your Heart."
But there is one crucial area where vintage standards are notably lacking: the story. For all its unexciting animation, Disney's own Fox and the Hound (1981) at least boasted a well-constructed narrative, accommodating both comedy and suspense without strain. The Secret of NIMH is a ragged job of work by contrast, nervously jumping from magic to comedy to quickly engineered tension. Most irritating of all, the secret is only revealed via an awkwardly placed flashback; children who appreciate narrative logic as well as action will be asking their parents lots of questions. The script consistently fails to find the sophisticated style its story-line demands, but Jeremy the comedy crow is well voiced by Dom DeLuise, and John Carradine provides an inimitably sepulchral Great Owl.