The Secret of NIMH is a 1982 American independent animated fantasy adventure film directed by Don Bluth in his directorial debut and based on Robert C. O'Brien's children's novel Mrs. Frisby and the Rats of NIMH. Featuring an ensemble cast consisting of Elizabeth Hartman in her final film role as its protagonist, Mrs. Brisby, with Peter Strauss, Arthur Malet, Dom DeLuise, John Carradine, Derek Jacobi, Paul Shenar and Hermione Baddeley in supporting roles, the film was produced by Bluth's production company, Don Bluth Productions, in association with Aurora Productions.