—Arthur Conan Doyle, letter to his mother, December 3, 1911
It would be four years separating the publication of “The Second Stain,” in December of 1904, and the serialization of any new Holmes stories (beginning with "Wisteria Lodge," in 1908) and nearly a decade before a new Holmes novel, The Valley of Fear, in September of 1914. Some have wondered as to why this period of time did not merit the same reaction as the Great Hiatus of 1893 to 1901. One possible answer is quite Sherlockian in temperament: simply, that Holmes himself did not disappear. Taking “The Second Stain” and its mention of Holmes’s “retirement” into account, all was otherwise well and there was no cause for alarm. Indeed, even Conan Doyle remained proximal to his loyal readership, and in a personal triumph, had succeeded in achieving popular success outside the Holmes canon. The Lost World, and the adventures and exploits of Professor Challenger (a dead ringer for his author, fit and uniformed from his service in the Boer campaigns), captivated Strand readers from April to November of 1912, going on to further success (and sales) in book form.
But The Lost World was, if anything, simply one bud in a life that was blooming in abundance. Conan Doyle, who had dutifully cared for his wife Louisa throughout her struggle with tuberculosis, grieved her loss in 1906, shortly after The Return of Sherlock Holmes saw publication in book form. A year later he had found love again with long time cherished friend Jean Leckie, and soon settled in at Little Windlesham, in Crowborough. The growing family welcomed three new members during this period, Percy in 1909, Adrian in 1910, and Jean in 1912. With the stability of home and fatherhood, Conan Doyle allowed himself, for perhaps the first time, to utilize his formidable celebrity to take on causes and concerns around him, from politics (particularly Irish Home Rule and the colonial situation in the Congo) to sport (Conan Doyle was an excellent golfer and, in 1910, named captain of the Crowborough Beacon Golf Club, East Sussex).
Notably, it was during this time away from Holmes that Conan Doyle became most involved in criminal justice, assuming the role of consulting detective for two cases of wrongful imprisonment. The first case, in 1906, involved George Edalji, suspected of usual animal mutilations and terroristic threats. Police were convinced of Edalji's guilt, even though the mutilations continued after their suspect was jailed. The second case was that of Oscar Slater, convicted of bludgeoning an 82-year-old woman in Glasgow in 1908. Conan Doyle observed inconsistencies in the prosecution case and had a general sense that Slater was not guilty, placing his wits and his pocketbook against Scotland Yard’s. The Slater case would continue on for another 20 years, with Conan Doyle’s continued involvement finally succeeding for Slater in 1928. In an effort worthy of Holmes himself, Conan Doyle paved the way for judicial reform, championing the establishment of the Court of Criminal Appeal in 1907.
Though the stories would resume more quickly amid these other accomplishments, for nearly ten years, Conan Doyle avoided any further novelistic treatment of his creation. Soon, however, the winds of change would call the great detective out of retirement. That novel would be, no doubt, a welcome respite for the writer, to be back on familiar territory after a long decade of new changes and challenges.