There’s a point toward the end of our interview where local novelist Matt Coyle admits, somewhat humorously, that he’s unsure how he’s going to move on from Rick Cahill. There’s a sometimes mournful cadence to Coyle’s voice, a pronounced uncertainty similar to those who are fresh out of a multi-year relationship, uncertain what the future may hold.

“Twenty years in one relationship is the longest I’ve ever had by far,” Coyle says laughing from his Clairemont home. “And with Rick, it’s even the most successful.”

This is one of many instances in which Coyle speaks of his signature character not only as if he were real, but as if they’d been living together for nearly two decades. In many ways, they sort of have been. Coyle repeats the time frame for emphasis.

“Twenty years. I can’t imagine not writing him again. He’s a part of my life, strange as that sounds,” Coyle says. He changed my life.”

Author Matt Coyle will publish his 10th (and possibly last) Rick Cahill novel, “Odyssey’s End,” in November.

(Nelvin C. Cepeda/The San Diego Union-Tribune)

Lucky for readers of the Rick Cahill series of books, which centers on the private investigator that Coyle spent nearly a decade developing and first debuted in 2013 with “Yesterday’s Echo,” their favorite protagonist is going out (for now?) with a bang. Hitting bookstores on Tuesday, “Odyssey’s End” marks the 10th book in the series. Given the reverence with which Coyle speaks of the character he first conceived so long ago, it raises the question: why would Coyle want to move away from a character that has won him multiple industry awards and garnered him thousands of devoted fans?

“I think it was time to do a palate cleanse anyway,” says Coyle, who is currently writing his first book that doesn’t feature Rick. “I think that challenging yourself in a different way is important. I think that no matter where I was in my career, it would have been a good time to try something different.”

Like many of the other nine books in the series, “Odyssey’s End” finds Rick investigating a unique mystery, while also balancing personal relationships, protecting his family, and dealing with his own deteriorating health.

Each book takes place in and around San Diego, with real-life landmarks and neighborhoods featured prominently throughout the series. In the new book, Rick is hired by a former antagonist to track down a missing woman. Naturally, things get complicated and our hero ends up chasing down shadowy figures while being outgunned at nearly every turn. To add to his troubles, he’s also dealing with a body and temperament that’s rapidly diminishing due to what he believes is chronic traumatic encephalopathy (CTE), a brain disease that results from physical trauma.

“He definitely changed and I certainly didn’t see him with this disease when I first started,” Coyle says. “I didn’t go into it envisioning a regular character with a potentially fatal disease and I certainly don’t think my publisher ever imagined that. Why would you want to kill off a character who is doing well?”

Rather than keeping Rick ageless like many popular mystery and thriller characters, Coyle has allowed fans of the series to see Rick age in real time.

Matt Coyle holds a stack of his Rick Cahill private detective novels.

(Nelvin C. Cepeda/The San Diego Union-Tribune)

“When I started, I only had a couple rules that I wouldn’t break: First, I wanted every physical hit and every emotional hit to have resonance, to matter,” says Coyle. “He’s got plenty of emotional scars and he has plenty of external scars too, which I’m always having to remind myself which ones he has when takes his shirt off or something. But the rule was always that everything has to matter; everything has to add up.”

The other rule Coyle recalls initially instilling in the character was that Rick would not have any sidekicks. The author admits, however, that he’s enjoyed writing the character of Moira McFarland — Rick’s on again/off again counterpart since the second book — so much so that he ultimately decided to include her more in the series.

“They blossomed even thought they often have a very tumultuous relationship, sort of like an older brother/little sister dynamic,” says Coyle, more than once referring to Moira as the “conscience of the series.”

“I don’t think I would’ve got Rick to 10 books if she hadn’t been around to pull him out of the darkness a bit. She’s not a particularly funny person, but their interactions lighten things up a bit.”

Still, in a journey that Coyle looks back on as a series of “broken rules” and “happy accidents,” he says the “biggest challenge” has been to write each of the books as a stand-alone adventure. That is, the reader would not necessarily need to read the previous books to understand the current one. This episodic approach is often a “delicate balance,” as Coyle describes it, but one that he’s tried to perfect.

San Diego author Matt Coyle at is home in Clairemont. In November he will publish “Odyssey’s End,” the last (at least for now) of his national bestselling 10-novel series about the fictional San Diego private investigator Rick Cahill.

(Nelvin C. Cepeda/The San Diego Union-Tribune)

“Everything that happens to this guy in one book carries over to the next book,” says Coyle. “For a new book, you have to give a new reader a sense of how this guy got here — how he sometimes makes irrational decisions and has a darkness that seems to follow him — but you don’t want to bore old readers by putting too much backstory in there.”

Another testament to Coyle’s strengths as a writer is how he doesn’t shy away from the tedious nature of private detective work. Sure, there’s plenty of suspense, intrigue and red herrings, but there’s also stakeouts, injuries and jumping fences to catch, or even get away from, the bad guys. These expository moments help the reader form a bond with Rick, giving the character an everyman feel as opposed to the bang-bang-shoot-em-ups that saturate the mystery and thriller genres.

“Of course I don’t want to bore the reader, but I also want to give them a sense of what Rick is thinking,” says Coyle. “Even when he has to kill someone, he’s not blowing the smoke off the gun and putting it back into his holster. He realizes he took someone’s life and dwells in the cosmic karma of an act like that. Yes, those are bad people, but it’s important to explore what that does to him.”

Reflecting further, Coyle states that Rick may have never existed at all if not for a series of karmic events in his own life.

Coyle grew up in a “tract home section of La Jolla” where he says he always wanted to be a writer after his father gave him Raymond Chandler books to read. Even after graduating from UC Santa Barbara with an English degree, it still took Coyle three decades of working in the restaurant and golf industries before he came back to writing.

“Those jobs, especially the sales jobs, they prepare you for the writer’s life,” Coyle reflects. “There’s a lot of rejection in the writer’s life and if you work in sales at a company, you’re used to that rejection. It really does help.”

San Diego author Matt Coyle at is home in Clairemont. In November he will publish “Odyssey’s End,” the last (at least for now) of his national bestselling 10-novel series about the fictional San Diego private investigator Rick Cahill.

(Nelvin C. Cepeda/The San Diego Union-Tribune)

One day, when the golf company he was working at was restructuring, he says he could have told his supervisor what he wanted to hear and remain employed. Instead, he was honest with what he believed were his strengths and was let go.

“It’s a decision that probably cost me a lot of money,” recalls Coyle, adding it was then that he decided to return to his first love of writing. “In a way, that decision saved my life.”

And just as Coyle has saved his signature character’s life dozens of times over the years, he’s quick to point out that, in many ways, Rick has also saved him. The climax of “Odyssey’s End,” while wholly satisfying, does leave the reader with many questions as to the hero’s fate.

“I’m so lucky to have readers,” Coyle says. “While I don’t think many of them want Rick to go away, if he did in this book, I think they’d at least think it made sense.”

While Coyle is reluctant to fully commit to an answer on whether he’ll revisit Rick in the future, or even reveal whether he’s alive, the author is ready for the next chapter in his own life.

“I’ve been in his mind for 20 years,” Coyle says. “I can’t imagine not writing another Rick book. I just can’t.”

He pauses before adding, “But if I don’t, this would be a good way to end it.”

The book jacket for Matt Coyle’s novel “Odyssey’s End.”

(Courtesy of Andrew Abouna)

“Odyssey’s End: A Rick Cahill Novel” by Matt Coyle (Oceanview Publishing, 2023; 320 pages)

Warwick’s presents Matt Coyle

When: 7:30 p.m. Tuesday

Where: Warwick’s, 7812 Girard Ave., La Jolla

Admission: Free

Online: warwicks.com

Combs is a freelance writer.