Casarett’s ethical Thai detective, nurse Ladarat Patalung, returns in The Missing Guests of the Magic Grove Hotel (Redhook, Dec.).

What led to your starting this series?

I created Ladarat as the embodiment of what I think is the best of Thai culture in general, and Thai health care in particular. My experiences teaching at a medical school in Thailand made me think about how the Western concept of medicine sometimes clashes with Thai culture. And how—maybe—the traditional Thai culture might make some aspects of medicine and health care better. As I spent time on the wards in Thailand, I was impressed by how some of the most advanced medicine is softened by the emphasis on compassion and empathy. So even when treatment is very aggressive, there’s a layer of kindness and support that’s not always present in the same situation in the U.S. Ladarat embodies that, and since she’s spent time in a big, busy hospital in the U.S., she recognizes—and appreciates—some of the most unique aspects of Thai medical culture.

In what way have your own experiences as a doctor influenced the books?

These aren’t medical mysteries, by any means. Still, so many of the medical and ethical conundrums she wrestles with are things that I’ve faced in the past. For instance, as she struggles with how to talk to the family of an injured man about what they can hope for in terms of recovery, I’ve realized that the things that she says (or the things that she wished she had said) reflect pretty well the conversations that I have every day with my patients. One of the reasons I like Ladarat so much is that she genuinely enjoys having those conversations. She likes finding the right questions to ask, and thinks very carefully—as I do—about how to ask them.

Why did you choose a nurse instead of a doctor for your lead?

Doctors are boring. Everybody writes about doctors, and people have so many preconceptions about what they do and how they think. Besides, a nurse ethicist is much more interesting to me because she doesn’t have a lot of power or status; she needs to get people to do the right thing through nudges and guilt. That offers many more potential plot lines than, say, a doctor who just tells people what to do.

Your novels join quite a few others that are set in Thailand. Why do you think the country is such a popular setting for crime fiction?

Thailand is a bewilderingly complex puzzle of country, with lots of pieces that don’t seem to fit together. For instance, it’s a very traditional place in some ways, but condones and even encourages prostitution. It’s a democracy that worships royalty, and also an ancient farming culture that takes enormous pride in its cities.