CAMDEN — Although she’s published 26 books, had a TV series based on her characters, and lands regularly on best-seller lists, Tess Gerritsen worries about whether her work will sell.

She has seldom relaxed enough to just write what she wants to write. Until now.

Her latest book, “Playing with Fire,” focuses intensely on music, something Gerritten has been passionate about most of her life. She plays piano and violin, and hosts Celtic music jam sessions at her home. But never tried to publish a story about music or musicians before. She didn’t think it would be commercial enough.

“I have ideas deep in my heart that I know are not commercial. I have a little voice in my head that says, ‘Can you sell this?'” Gerritsen, 62, said. “Now is the time to stop thinking about whether it’s commercial and just see if there are stories I’m dying to tell.”

“Playing with Fire,” which came out in October, is about a violinist who finds a mysterious piece of sheet music in Italy, which she believes has horrific powers. Her family, meanwhile, begins to think she’s ill or perhaps crazy. Gerritsen herself composed the supposedly-cursed piece, “Incendio,” for the book. She’ll perform it on keyboard Tuesday at One Longfellow Square in Portland, along with Maine violinist Tracey Jasas-Hardel, as part of the Portland Press Herald/Maine Sunday Telegram’s Maine Voices Live series.

Gerritsen didn’t sit down one day and decide to write about music. The idea came to her unexpectedly, in a dream, almost forcing her to consider it. “Playing with Fire” has gotten critical praise but readers have been “hot and cold” about it, Gerritsen said. She has an email address on her website, so readers can easily tell her what they think. Many feel like the book’s ending tricked them, she said, but Gerritsen said the clues to the eventual ending are visible throughout the book.

Writing “Playing with Fire” has started Gerritsen on a path of pursuing projects she has a definite passion for.

She’s working on a horror film called “Island Zero” with her 32-year-old son Josh – she wrote it, he directed. She also is considering making a documentary film about man’s long fascination with the pig, from Roman mythology to wild boar hunts to pigs as companions.

And she’s become something of an advocate for creative rights. She sued Warner Bros. in 2014, claiming she was owed more than $10 million of the profits from the Oscar-winning film “Gravity.” She had sold the film rights to her 1999 novel “Gravity” to New Line Cinema, later acquired by Warner Bros. But Warner Bros. never paid Gerritsen the money she says she was owed under the contract, claiming they did not acquire New Line’s contractual obligations. The book and the film both focus on a woman in a space shuttle or space station, and include perilous crashes and collisions in space.

Gerritsen says she learned how hard it is for writers to protect their work at times, and that some 50 similar suits filed by writers against studios over the last 20 years were all unsuccessful. She eventually dropped her suit, she said, partly so she could retain the right to speak publicly about it.

While her own drive to succeed is strong, she also has a strong desire at this point in her career to take a stand on behalf of other writers. There’s a page on her web site titled, “My Gravity Lawsuit and How It Affects Every Writer Who Sells to Hollywood.”

Best-selling author Tess Gerritsen in the backyard of her Camden home, which overlooks Penobscot Bay.

Best-selling author Tess Gerritsen in the backyard of her Camden home, which overlooks Penobscot Bay. Ben McCanna/Staff Photographer Ben McCanna/Staff Photographer

DEMANDING PARENTS, NATURALLY CURIOUS

Gerritsen credits her parents for pushing her to be successful and well-rounded. When she was 7 years old Gerritsen told her father, a Chinese-American restaurant cook, that she wanted to be a writer. He told her to study hard and seek out a career that would be more secure, maybe science or medicine. Wanting to please her parents, Gerritsen compromised. She became a doctor, then a writer.

The two disciplines have meshed pretty successfully for Gerritsen. Her medical school lessons and five years as a practitioner have come in handy, helping her create the popular “Rizzoli & Isles” book series about a medical examiner and detective working together. Her characters, Jane Rizzoli and Maura Isles, are the basis of the TNT TV series “Rizzoli & Isles.” She’s wrapping up work on the 12th book in that series, “Strange Girl.”

And her musical mastery was crucial in “Playing with Fire.”

“I have to be thankful that I had parents who were very demanding,” said Gerritsen, whose father was born in America while her mother was born in China. “I think it was an immigrant thing, striving to succeed, to push their children to succeed. When people talk today (negatively) about immigration, they forget the great energy added to society because of these strivers.”

Though her parents may have pushed her to learn specific skills, like medicine and music, Gerritsen’s natural curiosity has been central to her success as well.

“Curiosity is something you’re born with. I’ve learned about so many things through my writing, from mummies and the space program to music and Venice,” Gerritsen said, sitting in the living room of her oceanfront home in Camden.

Gerritsen usually starts her novels not knowing exactly what’s going to happen. But the basic idea for “Playing with Fire” came to her pretty much intact, in the form of a dream, while on vacation in Venice, Italy.

She dreamt that she was playing the violin, and she knew the piece was disturbing, but beautiful. There was a baby sitting next to her, and the baby’s eyes began to glow red. The child then became a monster.

When she woke, her mind was first filled with questions about what the dream might have meant. Her daughter-in-law was pregnant at the time, so could the dream be somehow connected to anxiety about her first grandchild? Soon the big question on her mind was what kind of book this idea might spur.

“It was clearly not a crime novel. So I walked around Venice and thought about it,” Gerritsen said.

She walked into the Ghetto, the Jewish section, with its many memorials to Jews who were deported from Venice during World War II. On one plaque she saw the names of deported individuals and noticed several with the last name Todesco. She imagined they were a family. In her book, the Todescos are forced from their home, including violinist Lorenzo Todesco. “I’ve never had a book where the beginning, middle and end is all there for me,” Gerritsen said.

The book also features a contemporary violinist and mother who discovers a mysterious piece of sheet music that apparently makes her child turn vicious when she plays. The book intertwines her story with the story of Lorenzo Todesco and his family.

Though Gerritsen felt comfortable writing about the musicians and music in the book, she was not as comfortable at first writing about the plight of the Italian Jews, something she knew little about before doing research. But she felt she understood Lorenzo, as a fellow musician.

“I took it from the point of view of the tribe of musicians, the fact that you can put the same sheet of music in front of a violinist from China or Italy and they can both play. So I thought I could write this story because I’m in that tribe,” Gerritsen said.

Gerritsen’s home has the trappings of an active, passionate musician. There’s an old black upright piano in the living room, the piano Gerritsen learned on as a child. In a room off the living room is a sparkling black grand piano, which Gerritsen plays today. Then there’s a case with her violin, bought in the violin-making center of Cremona, Italy. Gerritsen has opened her home to musician friends for jam sessions, mostly involving Celtic music. On vacation in Ireland a decade ago, she brought her violin with her and found that playing in pubs got her free Guinness every night.

Gerritsen’s “Incendio” has been recorded by Yi-Jia Susanne Hou, a solo violinist who tours internationally and performs with major orchestras around the world. Hou said when she began reading the music Gerritsen wrote, before she knew what the book was about, the piece spoke to her.

“It was like a magical portal opened, and I started picturing things, even though I had no idea what the book was about. It was haunting and beautiful and pulled me in,” said Hou, who has performed with Gerritsen during book promotion events. “I think it’s absolutely astonishing that she was able to convey so much with this piece of music.”858986_139475 FIRE34.jpg

DOCTOR IN HAWAII, WRITER IN MAINE

Gerritsen grew up in San Diego, where her father was a restaurant cook and her mother a social worker whose parents sent her to America when Communists took over after World War II. Gerritsen’s mother never saw her parents again.

Gerritsen said San Diego was “more like small-town” when she grew up. Her family was “firmly middle class.”

She eventually attended medical school at the University of California, San Francisco, where she met her husband, Jacob Gerritsen. The couple moved to Honolulu, Hawaii, where both worked as doctors, and they lived there for 12 years.

Gerritsen practiced medicine for about five years, before having her two sons. She says what she liked most about being a doctor was meeting people from all walks of life and hearing their stories. She didn’t like the unpredictable hours and emergency calls late at night.

Staying home to care for her oldest son, Gerritsen decided to start writing, when he was napping or at night. Her first novel, “Call After Midnight,” was published in 1987. But it was her first medical thriller, “Harvest” in 1996, that marked her debut on the New York Times Best Sellers list.

MAKING THE MOVE

Though Hawaii was a beautiful place to live, Gerritsen said she always felt slightly unsettled living on an island, cut off from the world by water. After vacationing in Maine, she and her husband decided to move to Camden, about 25 years ago.

They rented a home at first, and Gerritsen didn’t feel “financially secure enough” to buy the oceanfront home they now live in until 2003.

One day while Gerritsen and her son were weeding the garden at Josh’s Lincolnville farm, Gerritsen started talking about making a film about killer pigs.

“She said to me, ‘Let’s make a horror movie. They’re fun, and they have a great rate of return,'” Josh Gerritsen remembered. “And I loved the killer pig idea.”

They soon decided to make a movie together. Though not about killer pigs.

Instead Gerritsen wrote a script for a horror film called “Island Zero,” about the horrific happenings on a Maine island after the ferry stops coming. Global warming figures in the plot, as Gerritsen explores what sort of monstrous things might be “dredged up” from the ocean by man’s tampering with the environment.

The film’s best-known cast member is Laila Robins, a veteran actress who played the ambassador to Pakistan on the Showtime cable series “Homeland.” It was filmed around Camden in March and funded by the Gerritsens. They hope to complete editing and post-production this fall and submit the film to festivals, with an eye for a possible release to theaters next year.

Tess Gerritsen says that if the film “makes back its budget,” she’d like to make another one with her son.

But she hasn’t given up on pigs. Instead, she’d like to make a documentary film about mankind’s fascination with pigs. She’s considering a documentary, instead of a book, because of the visual possibilities. Her son is experienced with drone photography, and Gerritsen likes the idea of using drones to film a wild boar hunt. She says the film could explore Roman myths about pigs, truffle hunting, pig slaughters, the personality of pigs and why so much of the world’s population won’t eat pigs. She doesn’t know everything there is to know about pigs, yet, but she knows how to ask questions.

“I’m always asking questions, and that’s the cool thing about what I do,” Gerritsen said.

Her questions lead to stories, stories she can’t wait to tell.