(CNN) -- We should all be so lucky to have friends like Elvis Cole and Joe Pike. Private detectives in modern-day Los Angeles, they're the stars of best-selling author Robert Crais' award-winning series of crime novels. Elvis and Joe have been busting bad guys and thrilling millions of readers since 1987's "The Monkey's Raincoat." The books are international bestsellers, published in 42 countries, and have developed a fervent following.
In "Taken," Crais's newest novel, his 15th featuring the daring duo, Elvis and Joe take on an especially bloodthirsty group of criminals called bajadores. They are bandits who prey on other bandits along the U.S.-Mexico border, dealing in drugs, murder and kidnapping.
"Taken" is intense and fast-paced and reads like a big-budget Hollywood blockbuster. Though that's not surprising when you consider Crais began his career writing for television series like "Hill Street Blues," "Cagney & Lacey" and "Miami Vice."
CNN recently spoke to the author about his new book, his loyal fans and why he's refused to bring Elvis and Joe to the big screen. The following is an edited transcript.
CNN: How has writing about Elvis Cole and Joe Pike changed over the course of the series?
Crais: I really strive to bring something new to each book. I don't want to write the same book over and over again. I've done Elvis books; I've done Joe books; I've done mixed books, but this time, I made a conscious decision I wanted to tell a story where I could split the book pretty much down the middle and give them 50-50 equal footing so they both have their starring roles. When I discovered this particular story, it just seemed a perfect way to do that. Part of the book, they're working together. Then there's Elvis' track through the story, and there's Joe track, where he's trying to find Elvis and save him. So it just seemed like an ideal way to let these guys share the stage.
CNN: In "Taken," the story jumps between several points of view and moves back and forth in time. How difficult was it to put together?
Crais: It was like a crazy puzzle that kept changing. You should have seen my office. I have these huge black foam boards on the wall, and tacked to them, I have these white punch cards with my story ideas, scenes and notes. I kept juggling these cards and amending them, making little scrawls on them. Notions came to me, things changed, and I literally shuffled them around like a deck of cards, trying to bring them all into focus so the events were as exciting as I could make them.
CNN: How do you start a novel? What comes first, an idea, an image, a scene?
Crais: It could be any of the above, but it's usually an image, almost always driven by a character moment. In "Taken," it was the notion of Krista Morales and her hunger to know more about her mother's experience that night in the desert. I just saw her. It was literally my first image in the book. I saw her staring out into the black desert sky with this open-eyed wonder, trying to see the path her mother took to get to this country. All I had was her face in the moonlight, staring out there, and I just knew whatever she's looking for, I want to find. That was the engine that really kicked off the rest of the book.
CNN: "Taken" revolves around a kidnapping on the U.S.-Mexico border by bajadores. What prompted you to write about these bandits?
Crais: I had heard about these atrocious mass graves uncovered in Mexico south of the border: 52 people in one grave, 87 people in another, 164 bodies at a ranch with multiple burial sites. If you watch the news at all, you know Mexico is pretty much defining itself now as a war between the government and the various drug cartels. South of the border is fairly well-patrolled by armed groups of thugs who work for the cartels, and those guys end up preying on civilians, policemen and government officials, but they also prey on each other.
I found out most of the people who were found in those mass graves were immigrants who were headed North from as far away as Central America. They were trying to get to the U.S., and somewhere along the way, cartel bandits or "bajadores" would kidnap them, rob them, force them to call their families or employers or whoever and try to extort additional money out of them. When there was no more money to be had, they would just be murdered and buried in mass graves. The business was literally stealing people. The nature of this victim was very moving to me.
When you consider that the victim is basically an innocent, penniless person who's just trying to find a way to make his or her life better was super appealing to me, and it seemed like the type of people that Elvis and Joe would sympathize with and risk their lives to try and save.
CNN: While there's lots of action in your books, it seems like the friendship between Elvis and Joe is what keeps readers coming back.
Crais: Sure. The books are about Elvis and Joe. The books are about their friendship and who they are as men and human beings. I think that's why the readership has grown the way it has and why readers keep coming back to them. There's a value to their friendship that I think people admire and envy and want in their own lives. I know I do, so I kind of attribute it to other people, too. I would love to have either Elvis or Joe, preferably both, as my friends. They're certainly interesting guys, and we can live vicariously through them for their adventures, but there's something beautiful about these two guys and about having someone so trustworthy and dependable in your life. It's very comforting, I think.
CNN: Has the success of the series surpassed your expectations?
Crais: I'm certainly thrilled by the reaction. Honestly, I never would have thought the characters would have become as popular as they have. In the beginning, my dream was simply to make a living at it. I wanted to be a writer. I wanted to earn a living, but it never occurred to me that the books would become bestsellers. I mean, I'm glad, but none of this was by design. I wrote these guys because they're guys I wanted to spend time with.
Writing a book is a long and difficult process for me. I'm a slow writer, so I spend the year with Elvis Cole and Joe Pike in my head. I was thinking about this the other day. I wrote the first book in 1987. Literally every day since that time, Elvis and Joe have been in my head. They're always there. I started these guys because I like them. I still like spending time with them, and I think that's probably the reason the readers have embraced Elvis and Joe the way they have. Whenever there's a new book, they want to refresh that friendship.
CNN: Despite many lucrative offers, you've never sold the screen rights to Elvis and Joe. Why is that?
Crais: It's pretty simple. You know the old saying, if it ain't broke, don't fix it? I'm concerned that if there's a film of Elvis and Joe, that somehow it will interfere with the collaboration I have with my readers. I'm the first to admit this is probably a knuckleheaded fear on my part, but I have it nevertheless. Books are a collaborative art. Elvis and Joe don't exist until someone picks up one of the books and reads it. In the act of reading, you and I collaborate, and Elvis and Joe come to life inside your head.
What I've learned over time is that the Elvis and Joe you see and hear in your head, they are only yours. There might be however many hundreds of thousands of other people who've read "Taken," and each and every one of them is going to have a unique Elvis and Joe. It's going to be a little bit different from everybody else's because we all bring our own stuff to this. I find that wonderful.
To me, that is the great thing about books, and I guess part of me is a little scared that if I let Hollywood get involved, and even if there's a really good movie made, that somehow once you've seen the film, when you come back to the new book next year, that collaboration that you and I have is going to be a little bit different. Because then, the movie is going to have inserted itself. So I'm really jealous and guarded about that. I want your Elvis and Joe to be a product of yours and mine and nothing else.
Read an excerpt from "Taken" and find out more about Robert Crais on his website.