In Kasasian’s third Victorian whodunit, Death Descends on Saturn Villa, detective Sidney Grice must prove that his ward, March Middleton, is innocent of murder.

How did Sidney and March come to be?

I had just written a book about the Pre-Raphaelites for which I had great hopes. When it got rejected, I decided to write to console myself. My head was still buzzing with Victorian London, so a Sherlock Holmes adventure seemed like fun, but then I thought, Why adopt a child who already has a wonderful father in Conan Doyle when I could create my own children?

But there are Sherlockian elements in your novels.

I don’t think anyone can write about a Victorian detective duo without at least a nod to Sherlock Holmes. Rather than shy away from this, I decided to go one further and reveal that, far from Grice being based on Holmes, Conan Doyle actually got the idea for his character by reading about Sidney Grice, even using March’s father as a basis for Watson, and plagiarizing some of Grice’s adventures—such as the Silver Beard goat-swapping scandal, and the case of the man who found someone had painted his study in scarlet.

You’ve had a lot of jobs—factory hand, wine waiter, veterinary assistant, fairground worker, and dentist. How have they influenced your fiction writing?

I think working in different fields helps you to view life from different aspects. I know what it’s like to wait on people and be waited on. I know the tedium of working on an assembly line, but got a taste of the sense of comradeship of the men who had done it all their adult lives. On a practical level, my dental experiences helped me a great deal with medical matters. When I trained, students were still given a human body to dissect over an academic year, and I attended several postmortems, more than I needed to officially. I can’t resist putting in a few clues about teeth every now and then.

How do you approach integrating humor into grim, and bloody, murder mysteries?

I want to entertain readers, not plunge them into depression. Some of the things I describe horrify me—cruel deaths and abject poverty. I try to give some relief by making jokes between these scenes but never about the cruelty. Shakespeare was the master of breaking horror with more lighthearted moments—the drunken porter in Macbeth being an unequaled example. The biggest problem I have is restraining the humor. My wife, Tiggy, is very good at telling me when I’m getting carried away in the stories (and in real life).