Based on an adaptation of Robert C. O’Brien’s book, Mrs. Frisby and the Rats of NIMH, the resulting 1982 film was the first attempt by Don Bluth and his fellow ex-Disney animators to return to their hand-drawn animation roots in The Secrets of NIMH.
 
In the film, Mrs. Brisby (name changed to avoid a potential lawsuit by the Wham-O corporation) is a kindly mouse who lives with her four offspring in a cinder block on the land owned by a local farmer named Fitzgibbons. The family needs to relocate, as the farmer is soon to start his springtime plowing, but there is one problem – a young mouse named Timmy is sick with pneumonia and mom can’t risk moving the little guy.

Mrs. Brisby turns to a crow named Jeremy to take her to the Great Owl. The wise one instructs her to enlist the help of a group of super-rats that reside in Fitzgibbon’s rosebushes. She embarks on a treacherous journey into the rosebushes to find the highly intelligent rodents who have escaped from the National Institute of Mental Health, or NIMH. The leader, a rat named Nicodemus, tells the mother that her family’s patriarch, Jonathan is the hero that led the rats to freedom. In thanks for her husband’s sacrifice, he gives her a magic amulet and agrees to have the rat clan help the Brisby family. Using a special rope-and-pulley system, the rats do their best to move the mice’s home, but there is a hungry cat that looms and Mrs. Brisby will have to conquer her own self-loathing if little Timmy has any hope of survival.

The timing seemed perfect for The Secrets of NIMH. Disney’s animation factory was in the middle of a slowdown and the producers had a best-selling book for their source material. The only thing they didn’t count on was little green men from another planet. Most unfortunately, The Secrets of NIMH was released at the same time as a little Steven Spielberg film called E.T. and it never stood a chance.

Luckily that didn’t spell the end for Bluth’s directorial endeavors. He would find future success in hits such as An American Tail, The Land Before Time and All Dogs Go to Heaven. And later, without all the extra-terrestrial distractions, The Secrets of NIMH would find new life in VHS, and finally, in a high-definition DVD release in 2007. A direct-to-video sequel (that was in no way connected with Don Bluth) was also released in 1998 called The Secret of NIMH 2: Timmy to the Rescue to little fanfare.