The itch persisted, and intensified, during those years John Thompson spent on Wall Street. He wanted to write books. He wanted a taste of the thrill experienced by writers he admired: Michael Connelly, Jim Harrison, Cormac McCarthy.

Eventually, he got his chance. The success of his first thriller, “Armageddon Conspiracy,” launched his second career.

Recently, the now-resident of Charleston penned a young-adult book, “The Girl From Felony Bay,” his first in the growing genre. Thompson recently answered a few questions about his two careers and the way they’ve overlapped.

Q: You were an investment banker in New York City. Where did you work and what exactly did you do? Were you already writing books during those career years?

A: Most of my time on Wall Street was spent at Salomon Brothers. I worked at the company headquarters in lower Manhattan as part of something called New York General Sales and where I ran the Mortgage Sales Unit, about 25 people who covered banks, thrifts, insurance companies, state pension funds and money managers.

I was then the head of sales administration for the firm worldwide. I had absolutely no time whatsoever to write during those years. The yearning was there in spades, and several times I tried to start books, but only got a couple of pages written before life intruded.

I wrote a bit of poetry, a carryover from my time at Middlebury College, where I did a number of writing independent studies and subsequently wrote an honors thesis in my own poetry.

When I originally went to Wall Street, I intended for it to be a three-year stint, during which I would make a little money and learn about the “real world.” After that. I intended to go back and get my doctorate in English and become an academic and poet.

Q: I noticed that the protagonist of your first thriller, “The Armageddon Conspiracy,” is an investment banker. So did your banking experience influence your writing?

A: My years as a banker always involved reading whenever I could, always on airplane flights and every night before I went to sleep.

I read a mix of thrillers and literary fiction, both old and new, became a huge fan of Tom McGuane, Jim Harrison, Richard Ford and Cormac McCarthy on the literary side, and Lee Child, James Lee Burke, Michael Connelly, Stephen Hunter and others on the thriller side.

In my first couple of novels, I tried to be Jim Harrison, an irreverent guy who likes to fish, hunt, eat good food and drink good wine. The early efforts were good enough to attract agents to represent me, but not good enough to actually sell.

Finally, one of my agents suggested that I write a thriller. It was almost like I had been given permission to write a really tightly plotted book, and who doesn’t love a true roller coaster of a novel?

I took the suggestion and haven’t looked back. Brent Lucas (protagonist of “Armageddon Conspiracy” and “The Hong Kong Deception”) definitely came out of my Wall Street years, although, sadly, I am not 6-foot-2, not an ex-All Ivy football player and definitely not a black belt like Brent.

Q: Your output so far has been in the thriller and mystery realm. What about those genres appeals to you?

A: Back to the roller-coaster image. I love a book that keeps dragging me back, that won’t let me turn off the light or do any of the myriad of important things I am supposed to be doing rather than racing to the end of the next chapter.

The great fun of reading is finding books that are truly compelling and have such great characters and driving plots that they grip your attention like an angry pit bull and won’t let go.

Q: I think “The Girl From Felony Bay” is your first foray into children’s fiction, right? How did your approach to the subject change because of that? Was it easier or harder to write than your adult books?

A: When my youngest child was 12, she asked me to write something she could read (and my wife had already been urging me to do the same thing for several years). As I thought about how I might go about honoring her request, I asked my daughter to give me her favorite five books so I could get a really good idea of what a “great” middle-grade book was like.

She gave me “Hoot” by Carl Hiaasen, “Holes” by Louis Sachar, “The Lightning Thief” by Rick Riordan, “City of Ember” by Jeanne DuPrau and “Hunger Games” by Suzanne Collins.

I was blown away by how good they were, how well-drawn the characters were, how tight the plots, how truly thrilling the pacing was. They provided such a great example of what I love in a good book. And then (characters) Abbey Force and Bee Force and the extraordinarily complex history of the South and the Lowcountry and Civil War and plantation life all sort of fell into place for me, and I saw how a modern-day mystery might weave the past and the present together in ways that could be both thrilling and thought-provoking.

As far as ease of writing is concerned, I think there is more originality in the young adult and middle-grade space today than in the thriller genre.

I felt like I was doing something really original with “The Girl From Felony Bay,” particularly since so much young adult and middle-grade fiction involves fantasy elements or dystopian societies.

Of course, I have to qualify the claim to originality since a reviewer said, “Finally, a Nancy Drew for the 21st century.” That certainly put me in my place!

Q: “Felony Bay” is set in the Lowcountry. And you are active in the community, serving on a couple of boards. What is it about the Charleston area that inspires you or fuels your creative output?

A: I was born and raised in the Midwest (Toledo, Ohio) and spent my high school and college years in New England, and then most of my finance career years in New York City.

Not to take anything away from those other places, but compared to them, Charleston is a much richer tapestry: extravagant personalities; the Lowcountry landscape with horizon-filling green marshes; live oaks that twist and sag with palpable age; the extraordinary architecture; the unbroken lineage of so many folks who have been here since pre-Revolutionary times; the incredible and tragic complexity of slavery and its ongoing ramifications; the richness of Charleston’s history and the way it still lives here; the region’s unique food — everything about Charleston makes it come alive like a great character.

How can living in the midst of this incredible soup not inspire? And I am certainly not alone. I can’t imagine another place where I could live within a few hundred yards of major writers like Bernard Cornwell and Anne Rivers Siddons, and along with them count among my other friends in the community writers like Josephine Humphreys, Mary Alice Monroe, Nicole Seitz and Marjory Wentworth. This area attracts writers the way honey attracts bees.