In Purser-Hallard’s Sherlock Holmes: The Spider’s Web (Titan, Aug.), characters created by Oscar Wilde take part in a tale of murder and blackmail.

What gave you the idea of using characters from Wilde plays in a pastiche?

Crossovers with other literary fiction of the era is a popular subgenre of Holmes pastiche—but they’re generally crime or horror or science fiction or exploration—a natural environment for Holmes’s character and talents. I wondered how far a Holmesian crossover could stray from this model and still work. Wilde’s society comedies struck me as ideal contemporary material for such an experiment. Although his earlier plays are more melodramatic, even there the characters are unheroic and mostly unvillainous. Too, any peril relates to social ostracism rather than bodily danger, and the action rarely strays from the drawing-rooms of the upper classes.

What did using Wilde’s characters allow you to do?

I had a great deal of fun writing for characters I’ve loved for years. Imitating Wilde’s dialogue, which was written by a genius capable of making the most carefully constructed epigrams look effortlessly spontaneous, is a huge technical challenge, but the joy of depicting Holmes trading quips with Algy Moncrieff, or disputing with the formidable Lady Bracknell, was correspondingly rewarding. Equally, though, for Holmes and Watson’s presence to make any sense at all I had to craft a detective plot, and that meant constructing a web of connections and a backstory that linked the characters from The Importance of Being Earnest with those from other plays. Wilde wrote these as standalone fictions, with no intention of creating what we’d now call a shared universe, so building one for him was a literary game of sorts, similar to the one played by Holmes scholars who attempt to reconcile the contradictions and lacunae in the canon. It was enormous fun to play.

What was the hardest part of merging these fictional worlds?

The biggest challenge was the constant need to gauge the tone. Wilde’s characters are relentlessly trivial, refusing to take anything seriously or to think about it at all unless they can make a joke about it. The Holmes stories aren’t without humor, but in general they deal with serious, sometimes even grim, situations and consequences. I needed to respect the ethos of both, without either mocking Holmes or belittling Wilde’s characters. As it turned out, Holmes and Watson each have a lot to offer in a comedic context, without becoming parodies of themselves. Confronting the Earnest characters with events of serious import was a trickier balancing act, though drafting in some of the more melodramatic characters from the earlier plays helped.