In Death and the Conjuror (Mysterious, July), Mead gives magician sleuth Joseph Spector three impossible crimes to solve.

What about crafting seemingly impossible mysteries appeals to you?

I’m a big fan of stage magic. I like to read about the psychology of stage magic, and how to send the audience in the wrong direction. It’s comparatively easy to do in fair-play closed-circle mysteries in that you might be looking at, for example, the least likely suspect. But with an impossible crime, it’s a question of not just the whodunit but the howdunit, which adds a layer of complexity. It’s a competition between writer and reader in that you’re giving them all the tools they need to solve the puzzle—but you’re saying, I bet you can’t. That’s the fun of it for me.

How do you approach coming up with and resolving the impossibilities?

In terms of locked-room mysteries, the problem is always framed as a detective explains the impossible, whereas in reality, it’s the writer taking something that’s logical and making it seem impossible. So really, it’s not so much about coming up with a complex problem. It’s coming up with a simple problem that you pile up the complexities around.

You’ve said, “I think one of the best ways to gain an understanding of the human condition is by deceiving people.” Could you expand on that?

This goes to the idea of psychology’s place in crime fiction; writers like Agatha Christie and Ellery Queen had an acute understanding of the reader’s psychology. In golden age puzzle plots, you are, as a writer, focusing on the reader’s reaction. You have to have that understanding of where an audience is going to be focused so that you know how to misdirect them. In that respect, a successful murder mystery puzzle plot demonstrates an understanding of the reader in terms of that psychology.

How did you become a fan of impossible crime fiction?

It started with a short story that I read at about age eight or nine, “The Vampire Tower” by John Dickson Carr. Really, it’s a horror story, but it’s also a perfect impossible crime, featuring a murder victim found at the top of a sealed room in a tower. It’s just a perfect, neat little problem with a satisfying conclusion, but with also a great kind of surreal, nightmarish atmosphere. It was really that combination—of the atmosphere and the logic puzzle—that appealed to me at that age and led me to seek out Christie and other authors whose puzzle plots have less of an impossible element.