The joy she finds in writing and the empathy she feels for her characters was evident Tuesday when Paula McLain, author of the popular “The Paris Wife,” spoke in Darien.

McLain was introducing her new book, “Circling the Sun,” and Darien was the first stop on the tour on the day the book was published.

“The runaway success of that book was a great surprise to me,” McLain told an audience of about 200 people at the Darien Community Association. McLain had been a writer for 15 years before “The Paris Wife” took off, and she saw crafting her second book as “a responsibility and opportunity” to create a strong female character that was as vibrant as Hadley Richardson, Ernest Hemingway’s’ first wife and the main character in “The Paris Wife.”

She chose Beryl Markham, an early female aviator, to portray in “Circling the Sun.”

“I became obsessed with her life,” the author said.

McLain was abandoned by her mother at age 4, and lived in a series of foster homes. Beryl Markham was also abandoned by her own mother at 4 and reconnected with her mother at 20 — the same age McClain reconnected with her mother. McLain was astounded by the coincidences.

“It was inevitable that I found Beryl. It was my fate to write this book,” she said.

McLain delivered her talk with an enthusiasm for writing that she communicated to the audience throughout the event, sponsored by Barrett Bookstore in Darien. “How much fun is that?” she asked several times when relating how empathetic she was with her characters, or describing her visit to the homes and important places in Markham’s life.

In response to audience questions, McClain explained how her stories started in pieces as she researched the details of her characters’ lives, later weaving them together into one tale.

“It’s like a puzzle or a quilt — every little piece I have, I put together,” she said.

Shelia Daley, owner of Barrett Bookstore, said she was pleased with the turnout at the author event, especially in the middle of summer. “We drew a great audience,” she said. “We will do well with the book.”

“Paris Wife” was a big seller for the store, 314 Heights Road in Noroton Heights, and she expects McLain’s second novel also to be a big hit, she said. A copy of “Circling the Sun” was included in the event’s $28 admission price and the author signed books at the end of her talk.

McLain closed by explaining how her own difficult childhood impacted her writing and how closely she identified with her female characters.

“Those early childhood losses did prepare me . . . to become the writer I am and to disappear behind those masks and commune with these women,” she said.