Set in 1897 London, England. Basil is a skilled detective who has been trying to stop his arch-foe, Professor Padraic Ratigan for years. Every time Basil tries to stop Ratigan or when he tries to find a clue on his whereabouts, Basil gets outsmarted by the mobster and his clues become a dead end for him. When a young female mouse named Olivia informs Basil about her father's abduction, the detective becomes determined to bring Ratigan to justice. Basil soon gets help from Dr. David Q. Dawson and Toby, a smart yet resourceful dog owned by Sherlock Holmes, in order to stop Ratigan once and for all, who plans on overthrowing the mouse queen during her annual jubilee.
Throughout his career Mancini had proved that he could write staggeringly beautiful, memorable themes, as well as vivid and almost balletic action music. He felt that more traditional sounding cartoon music was required, and as such much of his score is somewhat mickey-mousey. It’s still good music, but it’s a world away from the sophisticated and emotionally powerful music for animated films we often hear today. Basil’s theme is first heard in the “Main Title,” a lively fully-orchestral piece for playful brasses, scampering strings, and trilling woodwinds, which has that appropriate but indefinable Englishness to it.