Don Winslow listens to the laughter of children out on the edge of America. Today, the crime writer has lent part of his ranch north of San Diego to a local school doing historical recreations of pioneer life, and the kids are excitedly throwing hatchets in the background.

“When you write books like this one, hearing a bunch of kids laugh is a good thing,” he says.

“This one” may very well be the author’s magnum opus. The Cartel is an epic novel about a showdown between a rogue Drug Enforcement Agency agent, Art Keller, and Adán Barrera, the Don of a major Mexican cartel that is consolidating power and expanding its influence. The novel is a sequel to Winslow’s 2005 novel The Power of the Dog and if anything it is more ambitious, violent, and profane than its predecessor.

“That was sort of the point,” Winslow says. “Things in Mexico and along the border got so much worse than my worst nightmares. The most horrific things that I wrote about in The Power of the Dog wouldn’t even make the newspapers today.”

In fact, it took some convincing for the novelist to even approach the work. The first suggestion came from Hollywood scriptwriter and producer Shane Salerno, with whom Winslow collaborated on Oliver Stone’s film adaptation of Winslow’s novel Savages and was backed up by the storied Knopf editor-in-chief Sonny Mehta, with whom Winslow had edited Power of the Dog.

“I worked on The Cartel for about five or six years,” he recalls. “First of all, it was me sitting on the sidelines and not wanting to get back in the game. I wrote Savages, and Kings of Cool, and Satori, which were real stylistic changes. But sitting here reading the papers, I finally decided that I had unfinished business. I kind of had to write my way back into it.”

If this all sounds like a fight between good guys and bad guys, think again. It’s more like bad guys and worse guys on both sides of this fight, with DEA agent Art Keller violating every ideal he ever held in pursuit of his singular goal.

“One of the books I read in preparation for writing The Cartel was Moby-Dick,” Winslow affirms. “Instead of chasing the great white whale, Art Keller is chasing the great white drug and the men who traffic in it. Much like the war on drugs itself, Art Keller and Adán Barrera are symbiotic creatures. They need each other to exist. The cartels wouldn’t exist without the DEA and the DEA wouldn’t exist without the cartels. And America’s desire for drugs co-exists with this country’s desire to stop the trafficking of drugs, which causes this schizophrenic attitude that is the heart of this problem. What I hope to portray to readers are the real human consequences of this kind of violence.”

One thing that has changed in the decade between The Power of the Dog and The Cartel is the militarization of the drug war, which becomes a significant theme of Winslow’s new novel.

“Militarization is a major part of this story, both for America and Mexico,” he says. “You can zero in on the moment when one of the cartel leaders meets a Special Forces operator and realizes what he can do with 30 guys like him. This launches an arms race, basically, that militarizes the fighting between the cartels. So when t he Mexican government gets around to fighting the cartels, they send in their own army. Now you have a completely militarized situation in what would otherwise be a law enforcement issue. We’re talking tanks and armored cars and machine guns. And because the cartels are thick with cash, they can buy all this shit, too. So now you have gun battles in Matamoros, Mexico and guys playing golf across the border in Texas are diving into sand traps to avoid the bullets.”

I ask whether the violence associated with the drug trade is counter-intuitive because it disturbs the flow of commerce.

“It is and it isn’t,” Winslow explains. “Peace is undoubtedly more profitable than war. But what we fail to realize up here is that the cartels aren’t really in the drug business. They’re in the territory business. A lot of the top cartel guys will never even see the drugs. It just isn’t interesting to them anymore. What they do is control the trafficking routes and then charge other people to use them. If they have to eliminate a rival from a territory, it becomes a war and it’s just the cost of doing business. Because the profits are so sensational, it becomes worth the cost and the reason those profits are so incredible is the prohibition of drugs in this country.”

For those that prefer a more cinematic approach, more of Winslow’s work is on the way. Warner Bros. has optioned his 2011 novel Satori, a prequel to the 1979 thriller Shibumi by Trevanian, as a vehicle for Leonardo DiCaprio. Meanwhile, Shane Salerno has optioned both The Power of the Dog and The Cartel with a plan to produce them as a two-film epic spanning four decades of the drug war.

“I think they’re big stories and I’m one of those guys that think that big stories are best served on the big screen,” says Winslow. At times, it does feel like you’re writing Game of Thrones, though. The Sinaloa cartel and Los Zetas were allies and then something very personal happens and then they’re blood enemies. At that point, everybody scrambles to forge alliances. Nobody wants to be the smallest shark in that pool, because that’s who gets eaten.”

Clayton Moore is a freelance writer, journalist, book critic, and prolific interviewer of other writers. His work appears in numerous newspapers, magazines, websites, and other media. He is based in Boulder, Colorado.