Meeting Roberto Saviano, the Italian investigative journalist and anti-Mafia crusader, is no simple matter. Ever since the Camorra, the Neapolitan mob, took out a contract on him in 2006 for exposing their crimes in his mega-bestselling book Gomorrah, Saviano, 35, has lived under round-the-clock police protection. He sleeps in police barracks and safe houses. He changes his cell phone number on a regular basis. He keeps his movements a secret from all but close friends and immediate family.

So when I made some inquiries ahead of the U.S. publication of his book about the global cocaine trade, ZeroZeroZero, I initially got nowhere. His American publisher, Penguin, was clueless about his whereabouts. A friend put me in touch with an assistant at his Milan-based publisher, Feltrinelli, who offered to pass on emails, but they went unanswered. Eventually I got hold of his personal assistant. Saviano was open to a meeting, she told me, but there were some caveats. The Carabinieri, Italy's military police, would have to vet me. My time with Saviano would be short. Ordinary interactions—a hangout in an atmospheric bar, a stroll through a piazza—were out of the question. "For the past 9 years Roberto has not been able to walk the streets in any city," the assistant, Manuela, emailed me before I flew to Italy. "What you'll see is exactly how his life is: moving from a closed place to another. I'm sure you'll understand."

A few days later, I found myself standing in front of a church on a busy avenue in the center of a major Italian city (for security reasons I can't disclose the exact location). A husky plainclothes cop wearing a black leather jacket, with a telltale earpiece and bulge at the hip, approached. He asked in Italian if I was "the American journalist," and gestured toward a pair of cars parked down the street. Two other Carabinieri stood, unsmiling, on the sidewalk. One opened the rear door of a Subaru Outback, and ushered me inside. Slouched in the back, his bearded face half-concealed beneath a blue baseball cap, was Saviano. He extended his hand, and broke into a smile. "We're going to a kind of office where I write and where I sometimes sleep," he told me, as the car sped away from the curb. The police had given him the apartment, he said, and it was the closest thing to a real home he has had in nine years.

First published in June 2006, Gomorrah was an angry, luridly detailed investigation into the Camorra's reign of terror in Campania, the region around Naples that is one of Italy's poorest and most crime-ridden areas. The book arose from Saviano's own experiences growing up in Casal di Principe, a town dominated by the Casalesi clan, which during its heyday earned hundreds of millions of euros a year dumping toxic waste, running protection rackets, trafficking in drugs, and smuggling everything from arms to human beings. When Saviano was a child, gangsters beat up his father, a physician, for treating a dying Mob victim he encountered on the street rather than looking the other way. In 1994 a Casalesi hit man murdered a beloved local priest, Don Peppino Diana, an outspoken opponent of the Camorra who dared his parishioners to resist the criminals in their midst. Saviano was a teenage boy when Don Peppino was killed. "It changed me for good," he says. After Don Peppino's death, the people of Casal di Principe organized a candlelight protest march, Saviano recalls, "and then everyone forgot about it. After a few days, newspapers began dirtying his memory, claiming that Don Peppino was killed because he was a womanizer. And then nobody wrote about him for the next ten years."

Gomorrah began as a series of short articles that Saviano wrote for various publications, evolving into a full-throated cry of revenge against the criminals who had cowed his neighbors into silence. Saviano reported from the docks of the Mob-controlled Port of Naples, befriended low-ranking camorristas in hardscrabble towns, even tracked fresh corpses with the aid of a radio that could get the local police frequency. Saviano named names and penned provocative scenes that seemed designed to enrage the clans, such as one in which Saviano urinates into the bathtub of a Mafia don. The book sold a remarkable 2.25 million copies in Italy, and eight million more around the world, making him a wealthy man. It inspired a movie adaptation, directed by Matteo Garrone, that won the Grand Prix at the Cannes film festival in 2008.

I asked ‘ how long would the security be?' and they said a fortnight. That was nine years ago.

It also made Saviano a marked man. At first many of the mobsters whom Saviano had come to know begged him for signed copies of the book, but as Gomorrah climbed to the top of the bestseller list in Italy, and police and media scrutiny of the Camorra intensified, the Bosses turned against Saviano. Four months after publication, a pentito, or informer, told the police of a meeting among the capos of the Casalesi clan, in which they voted to kill Saviano. Carabinieri picked him up at the Naples train station, put him in a car, and placed him under guard. "I asked ‘how long would it be?' and they said a fortnight," Saviano says. "That was nine years ago."