Though now a denizen of the San Francisco Bay area, the setting for her historical mysteries featuring Fremont Jones, Dianne Day spent her childhood in sultry Mississippi, as southern a state of mind as you can get. Imagine humidity so thick you can smell it, kudzu choking the trees, and the ghost of William Faulkner tap-tapping on a typewriter. The perfect breeding ground for a writer of novels that interweave both research and real-life as it was lived in the turn of the century, along with murder and characterizations so vivid you feel as if you know these people, despite their slightly starchy speech and the strange clothes they wear.

Beacon Street Mourning, a recent hardcover release from Doubleday, is the sixth in the Fremont Jones series and perhaps the last. The first, The Strange Files of Fremont Jones, won a Macavity Award given by the Mystery Readers International. I wondered how Day invented her popular protagonist, who seems to be a cross between Sherlock Holmes and Susan B. Anthony.

SUSAN McBRIDE - Welcome, Dianne. How did you conjure up Fremont Jones?

DIANNE DAY - She came to me in a dream.

Is Fremont Jones based on any true historical character?

The character of Fremont Jones is based on characteristics of many women who truly lived at that time in history. The commonly expressed opinion that Fremont is "a woman ahead of her time" is in error. There were many, many women like Fremont Jones, especially West of the Misssissippi. We haven't heard much about them because history books were recording the deeds of men and, for the most part, were also written by men. But by spending some time in a library that has holdings of unpublished diaries and journals, one will find that most of them were written by women very much like Fremont Jones in spirit.

To mention a few who became well known without having to go West: Margaret Sanger, who started Planned Parenthood and advocated birth control, Virginia Woolf, Coco Chanel, Martha Graham - and the list goes on.

Describe Fremont in three words. Then describe yourself in three words. Are you more like her than you are different?

Three words for Fremont: (a) courageous (b) curious (c) compassionate. Three words for me (a) intellectually curious (b) caring (c) a risk-taker. I think Fremont and I are more alike in nature than we are different, given that fictional characters are always idealized.

What made you want to write a historical mystery series?

I wanted to write a mystery series set in San Francisco with a female protagonist, and the only commercially viable way I could do that in the early 1990s was to make it historical. So it was a business decision - shocking but true.

Are you a history buff?

I am a history buff, but my chosen period is in the medieval history of England, Scotland and Ireland. I'm particularly interested in the pre-Christian period in Scotland and Ireland, and in the Celtic Christian Church. This period is extremely difficult to research. My dream has been to be able someday to go to the great libraries of the UK and Ireland for a year, or a series of months out of each year over a period of years, to do this research - although the older I get the less likely this is to happen.

Does the turn of the century seem especially intriguing to you?

The turn from the 19th to the 20th century does not seem so much intriguing to me as it was unusually significant. Most people, including myself, don't realize how many of the things we take for granted today had already come into existence and were beginning to change everyday lives back then.

I believe it's always important to know historically what happened and when, so that we can have a sense of perspective in our lives and in our decision making processes. And in spite of all that blather, I really chose it because when you think San Francisco and history, the next thing you think is either Gold Rush or Earthquake. I chose the 1906 Earthquake and the Fire which did more damage than the quake. (Fire and Fog.)

How do you conduct research for your books?

I do research in the library and in reference materials at home. In general, I've found the Internet too cumbersome for efficient research, unless I'm guided by a reference librarian.

How long does it take from idea to finished manuscript?

It takes about twice as long or longer to do the research as it takes to write the book. In some cases, particularly with Emperor Norton's Ghost, I found important research material toward the end, and I wished for more time but the publication schedule wouldn't allow that. Certainly, only about a fourth or less of research actually ends up in the book, and even then it should blend completely. Yet there have been times when because of the research, the story in my head wanted to go to a place I wasn't allowed to take it, because of time constraints and word length.

After six mysteries featuring Fremont, do you feel like you know her as well as yourself? Does that make it easier or more difficult?

I think of Fremont as a real person I'm getting to know from year to year. I certainly don't know her as well as I know myself. In fact, I'm not sure I know myself all that well either; I surprise myself all the time, sometimes pleasantly and sometimes not so pleasantly. I have enough ideas in my head to last well beyond a lifetime. Life is interesting. All you have to do to get ideas is pay attention.

Will the Fremont Jones series continue beyond the current book Beacon Street Mourning?

At present, I don't know the answer to that question. It's a business decision, and not mine to make. Beacon Street Mourning will not be out in mass market paperback until 2001, leaving plenty of time for my publisher to make a final decision.

Tell us about your current project with Clara Barton. What inspired you in this case?

My working title is Cut to the Heart. The book is essentially a thriller with a lot of medical Civil War stuff in it, half the characters are real historical people and half are fictional. Clara Barton, who was a real person, is the protagonist. As for what inspired me, I'm saving that for the acknowledgments section of the book, and for the author's note.

Do you have a special schedule for writing?

I go through a long period of gathering information, thinking and making notes, though I'm not organized about it like PD James and Elizabeth George, who make notebooks and such. I use corkboards, refrigerator magnets, pockets and notebooks that fit in a purse or book bag. I have to have photographs and maps. When I'm in this brewing stage, it kind of never stops. I may not look like I'm working but I am, all the time. An illness earlier this year has forced me to change my schedule. Five hours is my maximum now, and I have to work in the middle of the day when my energy is highest. I used to work a lot at night. Now at night I either read or answer email.

Name some of your favorite authors and describe briefly why they appeal to you.

PD James for her command of the language and for her fine mind. Elizabeth George for her ability to plot and subplot. Nevada Barr for her nature descriptions. John Sandford because he creates sexy men who appeal to me and his plots are good too. Jeffery Deaver for the intelligence with which he analyzed the business of writing,and set about to become a bestseller. Rennie Airth for his compassion, which brings light and air into River of Darkness. Val McDermid for her stunning versatility and for her good mind. Ian Rankin for his ability to hold me with Rebus in darkness without my becoming too afraid of losing my humanity. Dennis Lehane, for the same reason. Margaret Atwood for her courage in being true to herself, and for publishing her poetry. SJ Rozan because she just writes a damn good story whether from a man's or a woman's point of view, and because I never get tired of reading about New York. Michael Jahn, ditto - I never get tired of reading about New York.

What is the best and the worst part about being a writer for you?

The best part is that it's when I'm telling all these stories in my head that I feel the most whole and the most sane. The worst part is the business part.

Any advice for aspiring writers?

The whole publishing scene is changing so rapidly today that one piece of advice doesn't fit everybody anymore. This is why I've started Services For Writers. I used to say: Don't write unless you can't not write. I don't say that anymore. One thing I can still say to everyone is: If you want to write, then read, read, read.