When Holmes contemplates Moriarty, he sees an image of himself reflected in a perverse mirror. First, they look alike: Moriarty, like Holmes, is “extremely tall and thin” (p. 560). They share a taste for French painting. In a later novel, The Valley of Fear, we are told that Moriarty owns a work by Jean Greuze, paid for, it is implied, with ill-gotten wealth. Holmes expresses throughout the stories a decided preference for Gallic art, no doubt because his grandmother was the sister of French painter Emile Vernet (1789-1863). Holmes refers to the Professor as “the Napoleon of crime” (p. 559). Setting aside for the moment that such a phrase would be redundant for many an Englishman at the time, the only other reference Holmes makes to Napoleon is in the later story “The Adventure of the Abbey Grange,” where he compares himself to the Little Corsican. Except for the “criminal strain” that “ran in his blood” (p. 559), Moriarty might have become a highly esteemed colleague or even a soul mate.

Although on the simplest plot level, Holmes and Moriarty exist as two separate figures, on another level we are invited to see them as two sides of a single coin, like Milton’s “knowledge of good and evil,” “two twins cleaving together, leap[ing] into the world” or, in this case, out of this world. Europe’s greatest detective and its greatest criminal locked arm in arm, tumbling together into eternity over a vast abyss, form as powerful an image of the mysterious duality of good and evil as the framework of these stories allows. It recalls the structure of Shakespearean tragedy, where the expulsion of evil always requires the sacrifice of some human good.

It is probably impossible today to gauge the effect this final scene had on readers. Now every reader knows that Holmes did not meet his end at Reichenbach Falls, if only because of the huge number of pages still to read after “The Final Problem.” Even if we were momentarily deluded, we would soon find out that Mr. Sherlock Holmes returned from Switzerland, resumed his crime-fighting career, and finally retired to a country farm in Sussex, where he tended bees. This sheds a completely different light over our feelings for him. Instead of a tragic hero whose final sacrifice redeemed his society, he has faded into what Conan Doyle called in the Preface to The Case Book of Sherlock Holmes that “fairy kingdom of romance,” existing forever in the secure confines of an impossibly safe world.

At the time, Holmes’s death made an enormous impact on the reading public. Bank clerks and shopkeepers wore black armbands in mourning for the late consulting detective, and storms of letters poured into the Strand and to Conan Doyle himself, urging the resurrection of Sherlock Holmes. Conan Doyle writes of one woman who sent him a letter beginning “You brute!” But Conan Doyle was adamant in his refusal even to consider taking up his pen to revive his fallen hero.

So from 1893 until 1901 the reading public had to accept the idea that they had read the last of the remarkable sleuth. But then a young friend of Conan Doyle named Fletcher Robinson told him about an old legend from Dartmoor in England’s West Country, near Robinson’s boyhood home. The tale involved a spectral hound that haunted one of the local families. Conan Doyle and Robinson hatched out a plot together, which Conan Doyle then turned into a book. He saw right away that to solve the mystery at the heart of this legend, he would need to revive Sherlock Holmes. He wrote letters to his mother telling her he was writing “a real creeper” in which “Holmes is at his very best.” So in August 1901 the Strand printed the first installment of The Hound of the Baskervilles. Much advertised in advance, that issue of the magazine sold 30,000 extra copies. People lined up for blocks around the printer’s building on Southampton Street in order to get their copy of the magazine before it was shipped to their local newsstand or bookstore.

They weren’t disappointed, and few readers since have been either. The Hound of the Baskervilles is to my mind the best of all the Holmes stories. Most readers will agree with Conan Doyle that Holmes is at his best here. Watson, too, was never better: He acquits himself well in all the tasks Holmes gives him, even to the point of getting Holmes’s unqualified approval. The minor characters are for the most part well drawn, and the plot is skillfully paced.