Twelve years ago, Leta Serafim didn’t really know what she had with her first book, a mystery set in Greece featuring Yiannis Patronas, chief of police on the island of Chios. This is a law enforcement officer who, in his more than 20 years on the force, had never investigated a murder.

Serafim wrote The Devil Takes Half (A Greek Islands Mystery Book 1) over a summer “to help get myself through a difficult time” in 2014 after her husband was bedridden for six weeks. Then, she says, she got really lucky: She found an agent who sold the book within two weeks. At the time, it received a “get it” verdict from Kirkus Reviews, who predicted that the “immersive escapist mystery should put [Serafim] on the map.”

Her publisher envisioned a series and encouraged her to write a follow-up, but Serafim thought her book would be a stand-alone. She even resisted suggestions from her publisher that she should bring back Papa Michalis from the first book, an elderly priest and devoted fan of American police procedurals like Law & Order. (Patronashas thoughtful discussions with him about good and evil and justice.)

Happily, her publisher prevailed. Twelve years later, Serafim has published her fifth Patronas mystery, The Nameless Dead. In this ripped-from-the-headlines outing, Patronas’ investigation of the brutal murder of a Syrian migrant leads to a network of human traffickers. And yes, Papa Michalis is in it.

Kirkus calls The Nameless Dead “an engrossing and thought-provoking read…that unfolds at a brisk, engaging pace.” But this, Serafim reveals, is Patronas’ swan song. She is saying αντίο to her signature character.

Serafim confesses that growing up she “never really enjoyed writing [assignments] per se,” even though her teachers told her that she was good at them. Her father worked in the NASA space program from 1958 to 1975 on the unmanned Viking, Mariner, and Voyager missions. “He went from a one-room schoolhouse in Montana to NASA in Washington, D.C., where [we] lived,” she says. Her mother, a nurse, became an artist late in life, and Serafim gravitated toward the arts herself. “I was a reader “from the get-go,” she says, and she collaborated with her sister on stories that they then illustrated.

In college, she was a Russian studies major with the goal of being able to read Aleksandr Solzhenitsyn and Fyodor Dostoevsky in their original language. “I would have loved to have gotten a PhD in Russian studies, but I was no good at languages,” she says. “My professor took me aside and told me that there were excellent English translations available, which I took as my cue [to pursue other avenues].”

She pursued journalism. Why not creative writing? “Money,” she says with a laugh. Her first job was at The Washington Post during the Watergate years. She conducted research for the reporters on that epochal scandal, but primarily, she wrote obituaries. She next worked at the Los Angeles Times’ Washington bureau, which she called “a wonderful experience.” “There were 25 people there, and they were my family,” she fondly recalls.The Los Angeles Times was also a better fit for the kind of writing she wanted to do: feature stories. But her journalism background has served her well in building Patronas’ world and creating a vivid sense of place.

Serafim married a Greek professor, and the couple moved to his native country for five years. “I wanted to write about those experiences,” she says. “Greece is one of the most interesting and beautiful places. Journalism is fueled by curiosity, and I was fascinated by how the ancient and the modern coexist. You don’t see it as much as when I first went to Greece in 1975; the culture was much more intact. Tourism has taken its toll—42 million tourists every year. But I loved it; I loved exploring it. I find the Greeks endlessly fascinating in terms of their character and their nature. I was kind of an anthropologist trying to make sense of it, of how you decide to live on a piece of land—and not a particularly hospitable piece of land— for 5,000 years.”

The genesis of The Nameless Dead was an incident in which a boat carrying migrants to a Greek island sunk and a 3-year-old drowned. Serafim was haunted by the image of a coast guard officer holding the child in his arms and sobbing. “It’s been at least three decades since that event, and it was always in the back of my mind,” she says.

With her journalistic eye, Serafim writes vividly about the squalid and dangerous refugee camps:

No one had bothered to clean up Souda after the camp was closed; and remnants of the white plastic tents were still there, flapping in the wind. Stamped with the insignia of the United Nations refugee agency, UNHCR, they were a ghostly presence in the rain. Before departing, the migrants had written farewell messages on some of them. ‘I am alone,’ one read. ‘Love all people,’ another. Patronas could still see where the fire had ripped through the camp, the blackened plastic a mute witness to the attack. He wondered what had become of the people he’d interviewed at the time…They’d had so little—a copy of the Koran, an extra pair of shoes—and then someone had fire-bombed them and they’d lost even that. It still troubled him.

Over five books, Serafim has grown to love Patronas. “I really like him,” she says. “He’s not a particularly agile detective, and with women, he has no clue, but he tries to be a good man. He recognizes the humanity of the migrants he deals with.”

So why is she saying goodbye to her signature character? “He ends up with the happily ever after I wanted for him,” she says. “His marriage will survive. He’s going to be okay.”

She has begun work on a mystery that draws on her stint with The Washington Post. It concerns an obit writer tasked with transcribing poems submitted by loved ones on behalf of the deceased. One such poem describes a murder, and she is compelled to investigate. The title? Dead Beat.

Serafim lives in Sudbury, Mass., where she teaches creative writing. Three of her students have been published. “It’s wonderful to help people find their voice,” she says.

Phillip, her husband of 46 years, passed five years ago. She has two children and six grandchildren. One grandson dreamed that his underwear started flying around the room and that when he put it on his head, it enabled him to fly. “I thought that would make a good picture book,” Serafim says, “but he doesn’t want me to use his name.”

She did write a children’s book, Molly Saw a Bear, for her granddaughter, who is a budding writer at work on a series about Detective Phil, based on her brother. “She’s nine,” Serafim says. “She wants her stories to have a unicorn character.”

Serafim tries to write every day. “When I start a book, it goes slowly,” she says. “It’s like sculpting stone. Once I get going, I’m pretty fast, and I can work six hours at a stretch. If I don’t write, I consider my time wasted. Writing is about storytelling. As human beings, we share stories we hope will endure, and I’m glad to be a part of that community.”

Donald Liebenson is a Chicago-based writer who is published on vanityfair.com and in TheWashington Post and other outlets.