In Murder on St. Nicholas Avenue: A Gaslight Mystery, Thompson’s 18th Gaslight mystery featuring midwife Sarah Brandt and police detective Frank Malloy, the action centers on two hitherto supporting characters: Maeve Smith, who is Sarah’s maid, and Maeve’s policeman sweetheart, Gino Donatelli.

How strange was it writing a Gaslight mystery without your main characters?

I (and my poor readers) have waited a long time for Frank and Sarah to get together. They finally became engaged in book #15 and married in book #17. Almost as soon as they were engaged, however, I started getting fan letters begging me to get Gino and Maeve together. Readers love to see a happily ever after. So this was in the back of my mind when my publisher asked me to do a second, Christmas-themed book for 2015 that would feature secondary characters from the series. The timing was perfect, since Frank and Sarah would be honeymooning in Europe, and it gave me the opportunity to bring Maeve and Gino a little closer to their happily ever after.

You’ve been writing this series for close to two decades. Why do you think this saga has resonated so strongly with readers for so long?

How do you catch lightning in a bottle? No one really knows, but here’s my theory: readers come for the plot but they stay for the characters. A reader will enjoy one book because it tells an exciting and/or interesting story. That reader will return and read more stories if they care about the characters and what happens to them. I tried to create characters that were interesting to me, and they obviously managed to interest my readers as well.

What would your readers be most surprised to learn about you?

When my career as a romance writer tanked back in 1996, I didn’t know if I’d ever publish again, so I had to get a day job. I answered an ad and accepted a position as a professional fund-raiser. I turned out to be pretty good at it, and I worked full time as a fund-raiser for 18 years, the whole time I was writing the Gaslight mysteries, until I “retired” a year ago.

I heard a rumor that you drive a red late-model Mustang controvertible.

In my day job, I would call on the pastors of churches that supported our charity. One pastor drove a cute little Miata. I remarked that I’d been thinking about getting a convertible when I retired. She said, “Don’t wait.” Best advice ever. I traded in my sensible Taurus for the red Mustang and never looked back.