The Great Mouse Detective draws heavily on the tradition of Sherlock Holmes with a heroic mouse who consciously emulates the detective. Titus named the main character after actor Basil Rathbone , who is best remembered for playing Holmes in film and whose voice, sampled from a reading of " The Red-Headed League " [ 3 ] was the voice of Holmes in this film, 19 years after his death. The Great Mouse Detective was released to theaters on July 2, , to positive reviews from critics and financial success, in sharp contrast to the box office underperformance of Disney's previous animated feature film, The Black Cauldron The film's timely success has been credited with keeping Walt Disney Animation going after the previous film's failure by renewing upper management's confidence in the department, thus setting the stage for the Disney Renaissance when feature animated films would become the corporation's most lucrative and prestigious product.
In London, a young mouse named Olivia Flaversham celebrates her birthday with her single father, toymaker Mr. However, a bat with a crippled wing and a peg leg arrives unexpectedly and kidnaps Flaversham. David Q. Dawson, a retired army surgeon mouse newly returned from Afghanistan , meets Olivia and escorts her to Basil's residence.
Being busy already, Basil initially dismisses them. Olivia then mentions the bat that abducted her father, and Basil realizes that Olivia saw Fidget, the assistant of Professor Ratigan, the criminal mastermind whom Basil was working to catch. It is then revealed that Ratigan kidnapped Flaversham to create a clockwork robot replica of the Queen of the Mice, so that Ratigan can usurp her place as "Supreme Ruler of all Mousedom". Flaversham initially refuses to participate in the scheme, but capitulates when Ratigan threatens to harm Olivia.
Meanwhile, Fidget appears in Basil's window, then suddenly disappears. They trace Fidget to a human-sized toyshop; while searching the area, Dawson finds Fidget's checklist, and Basil discovers Fidget has been stealing clockwork mechanisms and toy soldiers' uniforms.
Fidget ambushes and kidnaps Olivia before Basil and Dawson can stop him. Basil does some chemical tests to the checklist, discovering it came from the "Rat Trap", a tavern near the junction of the sewer and the Thames.
