Crossover Cover: Encounters of Sherlock Holmes

This anthology from Titan Books has a few crossovers. In Stuart Douglas' "The Adventure of the Locked Carriage," an actor tells Holmes that he considers him a superior detective to Hewitt and "that foreign chap Dupin," referring to Arthur Morrison's Martin Hewitt and Edgar Allan Poe's C. Auguste Dupin. Mark Wright's "The Property of a Thief" pits Holmes against gentleman thief A.J. Raffles. Since Holmes and Raffles' creators were brothers-in-law, it is perhaps not surprising that there have been many crossover pastiches involving the two over the years. Paul Magrs' "Mrs. Hudson at the Christmas Hotel" reveals that as of 1925, Mrs. Hudson is now Professor Challenger's housekeeper. However, she must have gone back to working for Holmes at some point, since she is his housekeeper in Manly Wade Wellman's 1941-set story "But Our Hero Was Not Dead." Given Challenger's formidable temper, it's easy to guess why Mrs. Hudson's tenure as his housekeeper did not last. All of these stories fit into Crossover Universe continuity, but there are also three tales that have to take place in alternate universes. Editor George Mann's story "The Curse of the Night Crawler" has Watson working with Sir Maurice Newbury, agent of the Crown, and his assistant Veronica Hobbes. Newbury and Hobbes appear in a series of novels by Mann, which are set in a Steampunk London where Queen Victoria is kept alive by a crude life-support system, airships are common, and automatons perform menial jobs for lawyers, the police and journalists. A few of Mann's other books are set in the same universe as the Newbury and Hobbes books. Nick Kyme's "The Post-Modern Prometheus" has Holmes and Watson joining forces with Frankenstein's monster to defeat Dr. Henry Jekyll (aka Edward Hyde), who is using Victor Frankenstein's work for his own twisted purposes. Jekyll's activities and death in this story conflict with his role in The League of Extraordinary Gentlemen. Finally, Eric Brown's story "The Tragic Affair of the Martian Ambassador" takes place in an alternate reality where the Martians from The War of the Worlds made a second, peaceful voyage to Earth, and settled there after overcoming their vulnerability to terrestrial germs.