PW: Your new novel, The Mountains of Madness, is set on St. Joseph, a fictional island in the West Indies where you've set other stories. What's your fascination with this locale?

My wife Meg and I spent five winters with our two sons in Haiti. Later, I bought a run-down 541-acre coffee plantation in Jamaica and restored it. My "St. Joseph" is a combination of those two Caribbean countries. What do I find so fascinating about them? The people and their way of life.

Voodoo plays a strong role in many of your novels. Did you ever run across voodoo or its practitioners in your island experiences?

In Haiti I got to know some voodoo people quite well, especially Maman Lorgina, a leading mambo or priestess. With an invitation from Maman Lorgina, Meg and I went to attend one of her services. We found Lorgina in much pain from a badly swollen leg. There would be no service. Meg, who had been a physical-education teacher, said to me, "If you can find some olive oil, I'll try to massage the pain away." So I spent half the night driving our Jeep all over Port-au-Prince and finally found some olive oil in a little all-night eatery. Meg massaged the old lady. And Lorgina said to us, in genuine gratitude, "Anything you want from me, just say so." What I wanted was to learn about voodoo—real voodoo—and she was the right one to show me in the weeks to come.

You've always shown great respect toward voodoo in your writing. Are you bothered by flamboyant depictions of it in most horror fiction?

No, I don't feel that I'm that much different from other writers of horror. I just was fortunate enough to live in Haiti, learn to speak Haitian Creole and see a lot of voodoo at first hand. In other words, I write about voodoo as I saw it practiced, not from reading books about it.

You've been publishing popular fiction since the 1920s. How do you feel fiction markets have changed since the pulp era?

There were more than 100 different pulp magazines, and though many of them didn't pay a whole lot, a writer could make a nice living by writing for them if he worked hard. I sold them some 800 stories. When those magazines disappeared, I moved into the so-called slicks where rates were much better, and sold another 350 stories to such magazines as the Saturday Evening Post, Ladies' Home Journal, Redbook and Collier's. Now most of those are gone, too, and a writer pretty much has to write books if he wants to make a career out of it. I have two new books coming out this year, my 50th and 51st.

Although you've written all types of fiction over your career, for the last 25 years you've mostly written horror fiction. Why this concentration?

I've always enjoyed "creepy stories." It probably began when I was a boy and sang in a Boston church choir. We kids went to a camp near Cape Cod for two weeks every summer, and our choir-master read such stories aloud to us nearly every evening as we sat around a big campfire. Thanks, Mr. Snow!

The horror field has changed tremendously since your first stories. How do you keep your writing for it relevant?

I believe I try to write horror as it was when I most enjoyed it, meaning I try to focus on its subtleties rather than on mere gruesomeness.

Arkham House has just brought out Milt Thomas's Cave of a Thousand Tales, the second biography to be written on you in the last 20 years. How does it feel to be getting this kind of attention.

How do I feel about this attention? That at age 93 I've had an interesting and fulfilling life, thanks. And hope to keep going a bit longer. Why not?