On a picturesque fall afternoon, Keith Wille pulled into an unfamiliar driveway in eastern Connecticut and popped his trunk. He removed a “digger” (a heavy-duty bladed spade), an XP Deus wireless metal detector, and a White’s Bullseye II pin-pointer, a hand-held wand that vibrates or chimes when it’s near metal. Wille is twenty-eight and a member of the Ring Finders Directory, a group of metal-detection enthusiasts dedicated to recovering lost things at little or no charge. He had arrived at the home of Jim Flynn, who had e-mailed him three days before, asking for help.

After the two men were introduced, Flynn led Wille to a spot at the back of his newly sodded lawn, explaining that he had been stuffing hay—mulch for the young grass—into a black trash bag, when, he said, “I could sense something didn’t feel right.” He looked down at his hand. His platinum wedding ring was gone. “That was a sickening feeling,” he said. The band was insured, but money wasn’t the point. “My father had the same ring his whole life. I’d hate to be the person who got a second one.” His four-year wedding anniversary was days away. He dumped out the hay, and he and his wife and toddler scoured the lawn on their hands and knees, without success.

In the morning, Flynn, a forty-one-year-old financial planner who works for Morgan Stanley, searched the Internet for “local ring finder” and found the Directory. Wille wrote him back within the hour. First, they went over the basics of the case on the phone. A successful Ring Finder, Wille told me, must be a good detective as well as a good “detectorist.” Cold environments make fingers shrink, he said, and people often lose jewelry performing throwing or pulling actions like shovelling, swimming, or doing yard work. But he estimated that roughly half of his calls are from people who have thrown away their rings deliberately. Those can be harder to pinpoint, he said, because “people aren’t in a rush to admit they got in an argument.”

On the scene with Flynn, after their call, Wille asked some more-targeted questions: Was Flynn right- or left-handed? (Right.) Did he use gloves? (No.) Any distractions, like kids or phone calls? (No.) Where and how did he rake and dump the hay? (Front of the lawn to back; dumped there and on the patio.) Next, he determined three search areas, ranking them by priority. He strapped on his detector, and Flynn tossed his wife’s ring in the grass as a test. The machine let out a loud whang as he passed the coil over it.

Satisfied with the device’s settings, Wille began walking in straight parallel lines across the yard, swinging the detector in overlapping arcs. After a short while, he got a decisive beep. He knelt down and gently dug until he found an ambiguous scrap of metal. Then followed a pull tab, a bottle cap, a pancaked bullet, an antique shotgun shell, a 1957 wheat penny, and a 1946 silver dime. He made sure to show Flynn each item. “This whole thing is based on honesty,” Wille said, pointing out that people take a big risk when they call on a stranger to find their most valuable possessions.

Flynn looked hopefully at each piece Wille dug up, and seemed baffled by the pile of metal that was emerging from his yard. “This was just trees two months ago,” he mused.

“Everything you find tells a story,” Wille said. “That’s why I do this.”

The directory was started in 2009 by Chris Turner, a former professional soccer player from Vancouver, British Columbia. To date, it has three hundred and thirty-six members, spread across twenty-two countries and most of the United States. Since the group started, its detectorists have recovered about twenty-six hundred objects from parks, lakes, beaches, yards, and snowdrifts. The majority of calls are for rings, keys, and cell phones, but some finders have searched for time capsules and burial urns. Turner estimates that his members have an eighty-per-cent success rate.

Though the Ring Finders Directory is technically incorporated, it isn’t really meant to make money. Yearly membership dues start at $39.99. The members are all independent contractors, and almost all of them work on a reward basis, asking only for a guarantee of gas money. No one makes a living at it, and the rewards can vary widely. Turner, who works as a stand-in on film and television productions, reports having received a loaf of homemade banana bread for one find, and two thousand dollars for a set of rings that he found in a snowy mountain pass in the Colorado Rockies. Some Ring Finders have also been hired by insurers; in 2011, two members from Minnesota negotiated a rate based on a percentage of the value of their quarry, and made more than eighteen thousand dollars after retrieving a ring worth sixty-two thousand dollars.

Wille, who lives in nearby New London and works at a survival-training company in Groton, told me that he makes less in rewards than he spends on dues, partly because he pays to reserve a broad swath of Connecticut as his territory, which amounts to one or two calls a month. He hadn’t even asked Flynn for gas money to cover the fourteen-mile journey. Yet after almost three hours of non-stop detector-swinging, Wille was still probing for new leads, maintaining a running conversation with his client. “It makes no difference if I find it with the machine or I jog his memory and he finds it somewhere else,” he said.

“I really appreciate your passion and your optimism,” Flynn told him, as the light faded. He said that he felt a sense of closure just knowing it wasn’t in the yard. While Wille finished checking a section of the lawn, Flynn had been searching his car, and now he planned to look at the bottom of his pool, and to dig through his house, starting with some boxes he’d been unpacking.

Wille left for the evening, but kept in touch. After a few weeks, Flynn still hadn’t found the band, so Wille, who himself is engaged to be married, returned to search the rest of the yard. They never did find the ring. “If I don’t find it, it’s because it’s not there,” Wille told me.

A month later, though, he got two more calls, one for a ring in Newtown and one for an earring in Stamford. He booked both for a Saturday. In less than an hour, he found the Newtown ring, but on the way to Stamford he got into a car accident. He left behind his car, which was wrecked, and took a cab to a car-rental company thirty minutes away. Wille arrived in Stamford with daylight to spare, and soon found the earring. The two rewards came to six hundred and fifty dollars, the most he had ever received in a day—almost enough to cover his deductible and rental car.