Conan Doyle replied, “You may marry or murder or do what you like with him” (Howlett, “The Impersonators: Sherlock Holmes on Stage and Screen,” Beyond Baker Street, p. 188). Also he was careful in crafting the details of all his writing. The slapdash skid marks all over some of these stories are at great variance with the rest of his writing. All of these facts warrant at least the strong suspicion that many of these last stories were written by Conan Doyle but then changed, perhaps by someone much younger who may have thought the old-style Holmes stories weren’t sophisticated enough.

This supposition, however, is complicated by a couple of things we know about Conan Doyle. First, despite his reputation for hating Sherlock Holmes, Conan Doyle knew he would be best remembered for his remarkable sleuth; we can’t doubt that he was quietly proud of his creation. We wouldn’t think, therefore, that he would consent to letting a patently inferior work bear his name unless he produced it himself. And some very inferior stories have been in the canon now for nearly seventy-five years. Second, Conan Doyle has claimed he wrote the stories; he was an honorable man when honor meant something. We have the stories in his handwriting. For someone else to have written them, or even materially changed them, would mean that Conan Doyle conspired with someone whose identity has yet to be discovered to defraud the world about his involvement in what, for better or for worse, would be his chief legacy. In the absence of any hard facts to the contrary, it’s hard to believe that such a man would do this.

But it’s also hard to believe that such a conscientious writer produced the stylistic turn-around some of these stories represent. Take, for example, the story most at odds with all the facts about Holmes and Watson that Conan Doyle had established over nearly forty years, “The Adventure of the Mazarin Stone.” It was an adaptation of his earlier unpro duced play about Holmes, The Crown Diamond. When polls of various Holmes Societies are taken about the relative merit of the stories, it regularly places last. The reasons aren’t hard to fathom. First, it’s one of only three stories in which neither Holmes nor Watson is the narrator. A third-person narrator works for many kinds of fiction, but not for these stories, which depend so much on their realism that many people thought Sherlock Holmes was alive, and societies now devoted to him self-consciously maintain that whimsical illusion. A narrator like the one in “The Mazarin Stone” accentuates the fictional quality of the story, most unwelcome to many Holmes admirers.

In addition, the story is a rehash of several plot elements that had previously appeared in the Saga. Watson reminds us that the decoy bust of Holmes, in case we’ve forgotten, appeared earlier in “The Empty House”: “We used something of the sort once before,” he says. There, it was used to fool Colonel Sebastian Moran, “the best heavy game shot that our Eastern Empire has ever produced,” who carried a new weapon, the air-gun. In “The Mazarin Stone” the bust fools Sam Merton, about whom Holmes says, “Possibly you have heard of his reputation as a shooter of big game.” Sam, as Holmes refers to him several times (another un-Holmesian trait), has just bought an air-gun. Then at the story’s conclusion, Holmes slips the jewel into the pocket of Lord Cantlemere. This plot element of putting a stolen item under a client’s very nose for him to find was used in “The Adventure of the Naval Treaty” and again in “The Adventure of the Second Stain.”

This repetition of plot elements wouldn’t be so suspicious in itself. After all, in many of the stories since The Return, Conan Doyle had recycled plots. “The Mazarin Stone,” however, is also full of details inconsistent with all the other tales. Early in the story we hear of a waiting room and a second exit in the apartment at 221B Baker Street, things Conan Doyle had neglected to mention before. The choice of the name “Negretto Sylvius”—the Italian word for “black” and Latin for “woods”—happens to be the name of a rival magazine (Blackwood’s) that once accepted a submission by Conan Doyle but then never published it. This was not the sort of witty wordplay that Conan Doyle engaged in. The way Holmes talks in this story doesn’t sound at all like the dignified figure we’ve come to know over the previous fifty stories. He’s become a kind of jokester right out of the music halls. And when Holmes sends Watson to contact someone at Scotland Yard, he tells him to see Youghal, as if we’re supposed to know who he is, yet it’s a name we’ve never heard before.

In addition to all this, the plot is perhaps the weakest of all the Holmes stories.