The 80's are a seriously undervalued decade for Disney; each film has so totally embraced dark emotion in ways that other periods of Disney history rarely do. And like The Black Cauldron, this film's architecture if Gothic and lovingly spooky.
The Sherlock Holmes replication is a bit too blunt, and the mystery could perhaps be a bit more well, mysterious, but the imagery is beautifully Victorian. All culminating in one of Disney's greatest climaxes: a yellow-illuminated clocktower, with every inch a moving death, standing with English fog.
Professor Ratigan horrified me as a kid.