Serendipity played a big role not only in the overall concept of Jennie Field's fictional account of the life of 19th-century novelist Edith Wharton, but also in the specific development of the storyline.

The novel, "The Age of Desire," was published in hardcover in 2012 and is being released in trade paperback on May 28.

The story focuses on Wharton's later life, when, at 45, in a loveless marriage since her early 20s to Teddy Wharton, she embarks on an "illicit affair" with Morton Fullerton, a charming and handsome young journalist with a mysterious past-and present. A parallel plotline focuses on the relationship between Wharton and Anna Bahlmann, Wharton's childhood governess, who is now her literary secretary and dear friend.

The novel takes places during the Gilded Age - early 1900s - at the Wharton's Massachusetts estate, at Henry James's Mansion in England, and in the literary circles of Paris.

A huge Wharton fan, Fields had three novels under her belt when she was trying to determine a subject for this fourth novel.

In addition to her writing career, Fields is an advertising creative director, and was in Paris on business five years ago when, for the first time, she walked down the street Edith Wharton had lived on after her divorce. Fields had also just eaten lunch with her agent and asked her if she had any ideas for her next novel. Her agent's reply was, "You should write about your favorite author, Edith Wharton."

"Having just walked down Edith's street that very day, I knew I'd be living with her for the next few years. It was the answer I had been looking for," Fields recalls.

Fields says she didn't know a lot about Wharton's life although she did know she had a late-life love affair.

"I knew I needed a second character and I knew Anna Bahlmann had been with Edith most of her life, but no one had written about her," Fields says.

And some of what was written, she says, was inaccurate. Fields discovered that Bahlmann wasn't German as most biographers said, but was born in New York City.

After doing a lot more research, Fields says one evening she woke up in the middle of the night and put Bahlmann's name into a search engine and discovered that 135 letters from Wharton to Bahlmann were coming up for auction that week.

She asked for permission to read the letters - which are at Yale's Beinecke Library - which was granted. Although it didn't change her view of Bahlmann, Fields says it gave her more insight about the two women's complex relationship, which informed her novel - how Anna was Wharton's confidante and was very involved in her writing, yet, in many ways, she remained in a servant's role.

"The main theme in all of Edith's books is the idea of duty and passion. I realize that's been the theme in all of my books, too," Bahlmann notes. "Are women allowed to be happy? Are they allowed to have what they need? How much Edith abased herself to this man who truly wasn't worthy of her.

"It was painful to read those letters-and her diaries, too," Fields adds. "She was so insecure. When you read about her mother, you can see why."

Fields says she's pleased Wharton had an affair with Fullerton, despite his disreputable character. She points out that was no passion in "The House of Mirth," which was published in 1905 prior to Wharton's affair with Fullerton and that the Pulitzer Prize-winning "The Age of Innocence," published in 1921 after the affair, was full of passion.

"It changed her as a writer. It made her a better writer," Fields says.

Although there have been many recent books about the life of geniuses, including "The Paris Wife," and "Z: A Novel of Zelda Fitzgerald," Fields says she wanted to write about the female genius herself.

"I adore Edith with all her good points and bad points. At times, she wasn't very nice, but she was very real. She could be cruel to Anna, but she could also be generous of spirit. I think she did truly love Anna, and stood by Teddy longer than most people would have."

This is Fields' first autobiographical novel.

"I enjoyed writing this book more than any book I've written," she says. "I adored doing the research, recreating that time. It took me to a place far away from my present life, and I really enjoyed that."

Fields encourages people who haven't read much, if any, Edith Wharton-or only "Ethan Frome," because they had to in high school, to discover her.

"Reading Edith Wharton is like reading Henry James," she says. "She's so modern, so relevant today. Lots of her books are very ironic and funny. Most people don't realize that she published 40 books. She was really a remarkable woman."

IF YOU GO

What: Book talk and reading with Jennie Fields, author of “Age of Desire”

When: Thursday, May 30, from noon to 1:30 p.m.

Where: Bank Square Books, 53 Main St., Mystic

Info and reservations: Call the bookstore at (860) 536-3795.