For ten years, The Terror has laughed at both police and public. And for ten years, two of his erstwhile associates, Joe Conner and 'Soapy' Marks, have plotted revenge on the mastermind whose double-crossing sent them to Dartmoor prison without their share of the bullion stolen in a daring raid.

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.