|Violet Hunter consults Holmes in "The Adventure of the Copper Beeches"|
Consider my presentation on "Whydunit: Motives and Motivation in Fiction," for example.
When I make the point that what constitutes a plausible motive can change with the time period of the story and with the culture, I naturally turn to Sherlock Holmes for some great examples.
In the wonderfully Gothic, "Adventure of the Copper Beaches," a sinister father takes extraordinary steps to keep his daughter from marrying so that he can keep control over her income. I never noticed before how similar this is to "A Case of Identity," where a wicked stepfather schemes for the same evil motive.
Although this motive was perfect for the Victorian era, it wouldn't work so well today. At least, I hope not.
Neither would the indiscreet letters that lead to blackmail and potential blackmail in the plots of "The Adventure of Charles Augustus Milverton" and "A Scandal in Bohemia," respectively. One can't blackmail a person unless the exposure of the secret would cause grave harm to that person. Today, at least in America and Europe, the term and the concept of "indiscreet" are about as outdated as the bustle.
Fortunately for mystery writers, however, there's always something scandalous in every culture.That's one reason the game is always afoot.