In State of Wonder, Ann Patchett charts the changes in a doctor's life when she is sent to investigate the death of a research colleague among a remote Amazon tribe whose women unexplainably remain fertile well into old age. Also, they may have the cure for malaria.

Why the Amazon?

I wanted the book to be about a weird medical discovery, and so the Amazon, while clichéd, seemed like the only place to do it. I was really interested in malaria—Africa would have been better for malaria, or Indonesia—but then I thought, oh, not another continent! The Amazon is really excellent for the imagination.

Did you travel there to do research for the book?

I did. I didn't go to Manaus. I went to the Peruvian Amazon. We couldn't find the right kind of boat in Brazil. It was either a cruise ship or a raft with cockroaches. The boat I wanted existed in Peru. It was a chance to go down and look at all of those leaves together in one place.

Yes, at one point in the book, the heroine, Dr. Marina Singh, steps out from the jungle into a grove of these amazing trees, and feels intense relief.

You know, I feel that way about Tennessee. When you look out of windows, the trees are pressing against the glass on every side. Tennessee is so dense. It has a real Amazonian quality. Small wonder I wanted to write about this.

You also write about opera singers, politicians, and East Indian doctors in far-flung places.

It can take me a long time to write a book—sometimes I write a book for several years, so it has to be interesting, it has to be a stretch for me, far afield; otherwise I can't stay with it. The very, very best thing about my job is getting outside of myself, so I want to keep things adventurous. I love it when someone says to me, you know, I couldn't stop reading your book.

So you don't believe in the adage, "write what you know"?

It's very good advice if what you know is interesting. What I know is actually not interesting. I'm a housewife with a dog. I don't leave. But if one's imagination is up and running, one should be limitless.

In the book, the women of the Lakashi tribe bear children into their 70s. Did you make them up?

Yes. And I named them after my favorite cereal.

So the miraculous fertility, the moths, the hallucinogenic mushrooms—all made up?

When I was in my 20s, I wrote for Seventeen magazine —the bedrock of my career. "Sally (not her real name) is 15 years old and lives in Cleveland. She decided to wait until she was in college to have sex." I didn't even know that you weren't supposed to make that stuff up. And then I worked for Bridal Guide after that and I really made stuff up. I've always been a fiction writer.