Working prolifically in cinema, Lansbury appeared as Miss Froy in "The Lady Vanishes" (1979), a remake of Alfred Hitchcock's earlier film released in 1938. The following year's "The Mirror Crack'd" featured her in another film based on an Agatha Christie novel, this time as Miss Marple, a sleuth in 1950s Kent. Lansbury hoped to get away from the depiction of the role by Margaret Rutherford, instead returning to Christie's description of the character; in this she created a precursor to her later role of Jessica Fletcher. She was signed to appear in two sequels as Miss Marple, but these were never made. Lansbury's next film was the animated "The Last Unicorn" (1982), for which she provided the voice of the witch Mommy Fortuna.