Cthulhu by Gaslight

"Cthulhu by Gaslight" includes a lengthy roleplaying adventure, "The Yorkshire Horrors" in which the investigators join forces with the world's most famous consulting detective, Sherlock Holmes Extensive background essays provide period skills, social classes, world politics, biographies and timelines for the 1890s, maps and London location notes (including the best stores of the time), travel, criminals and police, Cockney slang, cost of living, royalty and titles, club life in London, the occult in the 1890s, prices, and clothing. A lengthy essay considers time-travel rationales for moving investigators of another time into the 1890s.