Looking for help in protecting the club, he befriended an Armenian-Argentine named Agop, who had contacts in the local police department. Enotiades learned that Agop worked for cocaine traffickers related to leaders of Colombia’s Medellín cartel, the Ochoa brothers, who were in prison. Under the direction of D.E.A. agents in Buenos Aires, Enotiades claimed that he knew distributors in the United States who were interested in buying bulk quantities of cocaine.

Orchestrating a sting is like staging a play, one with a script flexible enough to accommodate the words and actions of the oblivious key antagonist. Louis Milione, Enotiades’s former supervisor, told me that he and his team would draw flowcharts simulating the various ways in which a meeting could proceed. “You have to anticipate—O.K., if the target comes up with a proposal, this is our response,” he said. “If the target goes in this direction, you take it in this direction.” The undercover source mustn’t make any promises that he can’t keep, such as committing to arranging for a safe house to store drugs at a transit point. “We have to live with the lie that we create,” Milione said. “So if we put something out there that we say we can do, and then it’s time to do it and we can’t do it, that might be enough to create suspicion.”

Enotiades has enjoyed collaborating with the agents, although he hasn’t always agreed with their directives. Sometimes, he said, “I say no. I do what I feel I can do well. You have to be able to go by intuition. If it rains, you take an umbrella.” The D.E.A. attempts to minimize risks in a sting—by monitoring meetings as closely as possible, using distress signals and code phrases—but the most ambitious operations involve multiple parties and locations, and targets’ responses are harder to predict. In the summer of 1994, Enotiades flew to Salta, in northern Argentina, to meet with two traffickers, Luis and Miguel, who had agreed to supply ten thousand kilos of cocaine to the American buyers whom Enotiades claimed to represent. Before finalizing the deal, however, the cartel members wanted to meet the buyers face to face. The D.E.A. began working on a plan to have undercover agents play the American buyers, but the traffickers grew impatient, and on Thanksgiving Day Luis, Miguel, and another cartel member flew to Buenos Aires in a private plane.

Agop had warned Enotiades of the visit, but D.E.A. agents at the U.S. Embassy were on Thanksgiving break and weren’t responding to messages. When the traffickers arrived, Enotiades tried to explain that he had no control over the buyers’ whereabouts. But the men insisted on driving him to the airport. As they boarded an eight-seater turboprop, one of them took his passport.

Enotiades quickly realized his mistake. “What I should have done, knowing what I know today, I would have disappeared until I was able to get in contact with the controlling agents and get direction from them,” he told me. The plane made a stop in Salta. Enotiades recalled, “I said, ‘Listen, I know you don’t understand it, but, by the same token that I wouldn’t be able to find any of you over Christmas, I can’t find anybody over there.’ ” Instructed to keep trying to reach the buyers, Enotiades called Bill Weinman, a D.E.A. contact in Detroit, hoping to convey his predicament without drawing suspicion, but there was no response. The plane took off again, and finally landed on a dirt runway in the middle of flat grassland. As Enotiades got off, he saw guards with assault rifles idling in front of a large barn. One of them handed him a phone, and asked him again to call the buyers in the United States. Enotiades tried Weinman again, to no avail. His hosts ushered him into the barn, where piles of cocaine, compressed and packaged in plastic wrapping, were stacked on wooden pallets, and gave him the phone, explaining that, if the buyers were not in Buenos Aires the next day, there would be trouble. Enotiades, who knew that the agents would likely not be at their desks until after the Thanksgiving weekend, left Weinman a string of voice mails. Weinman, who has since retired, recalled the panic in Enotiades’s voice.

Enotiades sat by the door inside the barn, listening to the guards talking about him—he recalls the phrases “son-of-a-bitch liar” and “dead meat”—as they cooked beef on a grill. Someone brought him a blanket, then locked the door for the night. After his eyes adjusted to the darkness, Enotiades found a spot where he thought he could feel a breeze passing beneath the wall of the barn. He began to move bricks of cocaine from one of the pallets, and then, using a plank, dug a hole in the dirt floor. Eventually, he began to claw out the dirt with his hands. “I started hurting, I really started hurting, and I didn’t know what to do,” Enotiades said, recalling that he tore open a brick of cocaine and covered his injured hands with the plastic, so that he could keep digging. Early the next morning, he squeezed under the wall, and then ran until he reached a dirt road, where a pickup truck gave him a ride to the nearest city, Clorinda, near Argentina’s border with Paraguay. He was so scraped and muddied that he recalls having to persuade the driver not to take him to a hospital. Instead, he contacted a friend, who took him to the U.S. Embassy in Asunción, and then on to São Paulo, Brazil, where D.E.A. agents got him a new U.S. visa. On Christmas Eve, a month after his ordeal began, he flew into New York City. Russillo, the D.E.A. agent, who helped him get settled in New York, told me that among the first things Enotiades needed were shoes and a winter coat, since he’d left South America in flip-flops and a shirt.

The D.E.A. won’t disclose how many sources have come to harm because of their work for the agency, but a 2015 audit by the Department of Justice found seventeen cases in which federal benefits were being paid either to the families of sources who had been killed or to sources who had been disabled. The report noted that the procedures for determining eligibility for such benefits were vague and inconsistent. It is possible that the number of people who have died or suffered injuries while working for the D.E.A. is higher.

Enotiades believes that the D.E.A. was negligent in not insuring that he had a means of getting in touch over the holidays. But, he said, “it was a bigger fuckup on my part that I thought I would be able to handle it by myself.” (A spokesman for the D.E.A. declined to discuss the case or “the specifics of any past or present D.E.A. confidential source’s involvement with D.E.A. investigations.”) The terrifying experience reminded him of how many losses he’d incurred on the job—once again, he was forced to abandon his home, his business, and his girlfriend. (Elena, like many of Enotiades’s friends, learned about his work only after news of the Liberian sting became public, and never knew why he had left Brussels. “I was very upset with him . . . too many lies,” she wrote to me. “Til today I don’t know what is true, what is a lie.”) Enotiades reminded me that, in 2011, after the Liberian sting, another D.E.A. confidential source who worked with him, a pilot who had a business registering airplanes in Malta, had been forced to go into hiding. The man, who preferred that I not use his name, told me, “My girlfriend of ten years had no idea what I was doing until that court case came out.” The relationship ended and the man closed down his business and moved elsewhere in Europe, where he has continued to work with the D.E.A.