As dark as my books get, they’re always about the hope that can push up through the darkness,” Dennis Lehane says via Zoom from his home in Los Angeles. “The word hope, I’d bet, shows up more in my books than anything other than the f-bomb. It’s hope and feckin’ hope. Feckin’ hope is everywhere.”

Lehane has written 13 novels, several of which (Gone, Baby, Gone; Mystic River; Shutter Island) have been turned into movies, and has worked on shows including The Wire and Mr. Mercedes. Though Lehane’s literary success is immense­­­­—his books have sold more than 10 million copies worldwide, according to Harper, his publisher, and have been translated into 37 languages—the demands of writing novels have taken their toll. He even wonders whether Small Mercies, his new novel publishing in April, could be his last.

“Writing prose got harder for me with every book,” Lehane says. “The better you are at this, the harder it gets. This could be my last book, or I could wake up tomorrow and have a story I have to tell. I don’t know. If it’s my last I think it’s a good bookend—a nice mic drop.”

Small Mercies is set in Boston in 1974, when the city’s public schools were ordered by a court to desegregate and student busing was put into effect, sparking protests and riots. “I had wanted to address school busing my entire career,” Lehane says. “The story of Boston is the story of busing.”

Lehane grew up in the rough-and-tumble Boston neighborhood of Dorchester, one of five children raised by Irish immigrant parents. As a kid, he was exposed to a lot of casual racism.

“People I saw every day were using the n-word,” he says. “My parents didn’t do it, but almost everybody else I knew did. It gives you a disturbing entrée into the human condition. Racism is passed down like bad genes.”

Lehane was nine in 1974 and remembers seeing an anti-desegregation protest while riding in the car with his father, who took a wrong turn into the path of picketers. “This was the galvanizing event of my life,” he says. “I thought, this is adult society? This is what we’re supposed to be looking up to?”

Small Mercies tells the tense story of a white South Boston mom who’s trying to find her missing teen daughter. The girl has been implicated in the death of a black teen on the eve of the busing crisis. Lehane wrote the thriller in 2021, in New Orleans, while working on the Golden Globe–winning crime drama miniseries Black Bird, which he created.

The novel’s flawed characters aren’t always easy to root for—and that’s how Lehane likes it. “I want my characters to be contradictory,” he explains. “We’re all fucked up as a species. There’s good in the worst of us, bad in the best of us. I find that paradox infinitely fascinating to write about.”

Ann Rittenberg, Lehane’s agent, says Lehane has a palpable enthusiasm for his craft. “When he’s cracked the spine of a new story he sounds like a kid at Christmas,” she notes. “People think that because there’s a dark side to his writing, he’s a moody person, but you’d enjoy having a beer with Dennis more than anyone else. He’s an old soul, an empath. The distinctiveness of his voice brings an immediacy to his characters.”

Noah Eaker, Lehane’s editor at Harper, says, “Dennis is constantly evolving. Every book shows a mastery of his subject. With Small Mercies I was under the spell of the mystery and, in the end, realized that Dennis was saying so much more about power and the ways it’s wielded in our communities—about a legacy of racism that the country doesn’t seem able to overcome.”

Lehane hustled in his 20s to become a writer. After getting a master’s degree in creative writing from Florida International University, he wrote stories while working side jobs (parking cars, tending bar). “I knew I couldn’t fail,” he says. His debut, A Drink Before the War, was published in 1994. “I didn’t want to wind up back at the Banshee on Dot Avenue and have my friends say, ‘Hey Hemingway, bring me a Bud.’ Not happening.”

A wiz at creating cinematic novels, Lehane was tapped in 2003 to write scripts for The Wire. Though he confesses, “I didn’t know what I was doing,” his success there led to a second career in Hollywood. In 2013, he left Boston for L.A., where he lives with his wife, a teacher he met in 2018 through friends, and his two daughters from his first marriage. “I was always an East Coast guy,” he says. “You’re only real if you’re from New York, Chicago, Boston, or Philly. Everyone else is nobodies from nowhere—that was my mentality. But I love it here.”

Lehane has a deal with Apple TV+, where he’s creating a series based on Small Mercies, as well as a series about arsonists inspired by the true crime podcast Firebug. He enjoys the collaborative atmosphere of a writers room—a less lonely world than that of the novelist. “I meet so many writers who are comfortable being alone or they’re socially awkward, and I’m not that way,” he says. “I like people.”

Amy Schiffman, who’s been Lehane’s books-to-film agent for nearly 20 years, has watched him excel in the competitive film industry. “Working with Dennis is a joy,” Schiffman says. “Even though he’s extremely successful, he’s grateful for everything. He has a big heart and is generous with other writers, particularly those who want to do what he does.”

Gillian Flynn, author of Gone Girl, credits Lehane with helping her become a writer. “Reading Mystic River enabled me to figure out how to write my first novel,” Flynn says. “I’m a Lehane-ologist. I’ve studied his storytelling for a long time. He’s one of the greats. He has this terrifying brilliance at taking on spiky, nasty truths in a way that’s brutally frank but incredibly human.”

The secret to Lehane’s success may be his ability to approach each story like it’s the last. “I’ve worked my ass off on everything I’ve written,” he says. “I’m proud of my work ethic. The guilt you feel as a child of immigrants who gets successful can only be mitigated by that. My old man, if he was still alive, would ask, ‘Are you working hard?’ Yes. ‘Well then, there you go. Cutting any corners?’ No. ‘Well then, there you go.’ ”

Elaine Szewczyk’s writing has appeared in McSweeney’s and other publications. She’s the author of the novel I’m with Stupid.