His character becomes more interesting to his readers and his creator alike when it evolves and deepens. The vehicle for this change can only be his relationship with Watson. The development of that relationship will be one of the themes that most interested Conan Doyle in these late stories. We’ll see further examples of it later.

In addition to the changes in Holmes, one also notices about The Return that many of the plots are remakes of older ones. As noted earlier, “The Adventure of the Six Napoleons” reprises “The Blue Carbuncle.” “The Adventure of the Norwood Builder” uses the same trick of feigning fire found in “A Scandal in Bohemia.” “The Second Stain” recaps several earlier themes. The important letter of state that goes missing recalls the same kind of letter in the “The Naval Treaty”; it is also returned to its owner as if it had never been gone, again like the one in “The Naval Treaty”; the theme of blackmail over an indiscreet love letter recalls “A Scandal in Bohemia.” “The Adventure of the Solitary Cyclist” repeats elements of “The Greek Interpreter.” The pressure to come up with new plots had always been the source of Conan Doyle’s irritation with the Holmes stories. Without such new plots, and under a time limit to come up with them, he simply recycled some golden oldies.

He also returned to the oldest theme in detective fiction, revenge. It’s a prominent theme in both the first two series and again in this one. “The Empty House” revolves around Colonel Sebastian Moran getting revenge on Holmes for Moriarty’s death. Jonas Oldacre of “The Norwood Builder” wants revenge on the woman who rejected his romantic attentions thirty years previously, so he stages his own death and frames her son for it. Abe Slaney kills Hilton Cubitt in “The Adventure of the Dancing Men” because Cubitt fired at him first while Slaney was talking to Mrs. Cubitt, a woman he had once wooed in the United States. Although he didn’t set out to revenge his lost love, the end result proved to be exactly that. The title character of “Charles Augustus Milverton” is murdered by a woman he had ruined because she wouldn’t pay him blackmail. And perhaps worst of all, by allowing Milverton’s murder and shielding his killer, Holmes himself resorts to revenge on Milverton for upsetting Holmes’s calculations to catch him.

One last note about The Return before we turn to the next series of stories, His Last Bow. While everyone has his or her favorites among the stories, a number are always bridesmaids, never brides. No one ever champions “The Adventure of the Three Students” or “The Adventure of the Missing Three-Quarter,” as the problems Holmes solves in those stories seem so trivial. The latter story, while dull as a detective yarn, becomes more interesting when one learns that Conan Doyle’s first wife, Louise, was an invalid for the last years of her life. During this time, Conan Doyle formed a strong attachment to another woman, Jean Leckie, who moved to a house near the Conan Doyles. Conan Doyle saw her whenever he could, but from all we know about them, their love was strictly platonic. A year after the death of Louise, Conan Doyle and Jean married. The story of the rugby player who keeps his sick wife in a secret hideaway merges the two women in Conan Doyle’s life into one. While this story may not appeal greatly to us, we can be sure it had a special resonance for its conflicted creator.

After The Return, Conan Doyle thought again that he was through with Mr. Sherlock Holmes. The last story in the volume, “The Adventure of the Second Stain,” begins by claiming that Holmes “has definitely retired from London and betaken himself to study and bee-farming on the Sussex Downs.” Conan Doyle never committed himself to another series of stories. He wrote his publisher in March 1908, however, that he would contribute a number of occasional new Holmes tales, to be called “Reminiscences of Sherlock Holmes,” but at his own pace, subject to no time pressure. These stories, as that initial title suggests, would reflect particular concerns of Conan Doyle going beyond exciting whodunit plots. Holmes would be made the vehicle for exploring changes in the modern world and other themes especially interesting to Conan Doyle.

Conan Doyle began the first such story, “The Adventure of Wisteria Lodge,” just days after King Leopold II had given up personal control of large areas of the Congo to Belgium in March 1908. A year later Conan Doyle wrote a blistering indictment of the Belgian treatment of the people of the Congo, but his first go at the cruelties of the African empire came in this thinly disguised fictional form. The plot concerns a dictator who has ruined a small country, fleeing with much of its wealth. Six months after the events in the beginning of the story he is found dead in a Madrid hotel in what is assumed to be a revenge murder by the widow of a diplomat he had killed.