Sherlock Holmes takes a vacation and visits his old friend Sir Henry Baskerville. His vacation ends when he suddenly finds himself in the middle of a double-murder mystery. Now he's got to find Professor Moriarty and the horse Silver Blaze before the great cup final horse race.
A young woman turns to Sherlock Holmes for protection when she's menaced by an escaped killer seeking missing treasure. However, when the woman is kidnapped, Holmes and Watson must penetrate the city's criminal underworld to find her.
Holmes, retired to Sussex, is drawn into a last case when his arch enemy Moriarty arranges with an American gang to kill one John Douglas, a country gentleman with a mysterious past.