On a recent Saturday afternoon, a group of women, middle-aged and older, gathered at a table in the public library in Sumter County, South Carolina. They were friends—some old, some new—with a common interest, and had been meeting every month since September.

This was wasn’t a book club or scrapbook workshop. They weren’t there to discuss genealogical research or share short stories they had written.

What brought these women to the library table was a mystery, and not the kind you could pull off the shelf. Armed with land maps, aerial surveys, binders and science-fair poster board, they were hoping to answer a question that had nagged at them for nearly two years:

What happened to Barbara Nave?

Nave was a resident of Sumter who vanished around the time of the 2017 Super Bowl, when she was 80 years old. A mother of two and grandmother to eight, she was spry and mentally sharp, working on a second doctorate, holding down a teaching job and volunteering with the American Red Cross and a hospice.

A year before she disappeared, she criticized a seniors-aimed website for its choice of actress Jane Fonda as an “aging role model,” noting her Vietnam-era politics and plastic surgeries. "I keep my wrinkles—and still look 20 years younger," Nave boasted in an online comment.

She was feisty and independent. She had a LinkedIn account and a Facebook page. In short, she did not seem like the kind of person who would have just wandered off.

The person who reported her missing was Kathleen Kreklau, 63, who waited patiently for police to figure out what happened to to her friend before deciding to take matters into her own hands and form a kind of ad hoc detective agency made up of a half-dozen modern-day Miss Marples.

On the crisp, sunny morning of Feb. 13, 2017, Kreklau went to check on Nave, who lived alone in a house surrounded by thick woods a two-hour drive south from Charlotte.

Nave had promised to email Kreklau earlier that month, when she was expected to return from visiting her son in Georgia, but Kreklau still hadn’t heard from her.

”I was busy, so I emailed in the middle of the week, and did not hear anything,” Kreklau told The Daily Beast. “Because she lives pretty isolated, and because she did have a hearing impairment, I always checked on her. She did not speak on the phone—she couldn’t hear on the phone—and she did not have a cell phone.”

She recalls she had told Nave in the past, “You need to learn how to text—that’s the best tool for you out there.”

After Kreklau reached out, one day passed, as did another, without any response.

“I emailed again, and still, nothing,” she said. “And then I decided to email the family and see if she’d stayed in Savannah for some reason. They said ‘no,’ and that’s when I went to check on her.”

When Kreklau arrived at Nave’s home on South Tondaleia Drive, some things didn’t add up. Nave’s car was in the driveway, and the driver’s-side window was rolled down halfway. Kreklau checked for tire tracks on the dirt road leading up to Nave’s house, but there were none.

The car, she said, “looked like it hadn’t been moved in a few days.”

“ It just didn’t make any sense to me. ” — Kathleen Kreklau

As Kreklau approached the house, she saw the door was open. Nave’s beloved Lhasa Apsos waited near the entryway. It was apparent that they had not eaten or had anything to drink for several days. Nave’s purse sat atop the kitchen counter.

“I knew if she was on the property, her dogs would be with her,” Kreklau said. “It just didn’t make any sense to me.”

“I thought, ‘Well, she’s out wandering around. I don’t want to call law enforcement and it not be anything important, you know,’” she recalled. “So I went and ran a few errands, and got some gas, and came back, and put a note on the door, and then I went someplace else.”

Kreklau made a third attempt to find Nave later that day, but had no success and decided to call the cops.

Police soon mounted a search of Nave’s 20-acre property. They combed through through the hardwoods and pines, the soggy underbrush. Authorities deployed helicopters overhead and eventually sent divers into the swamp alongside her land. Cadaver dogs were also brought in. Several weeks later, organizations dedicated to searching for missing persons joined in these efforts on foot and ATVs and even horseback. Polygraphs were given to family members.

Volunteers, meanwhile, distributed fliers. They chatted up neighbors in the hopes of unearthing a clue that could lead them to Nave, who was in the middle of writing a dissertation for her second doctorate when she vanished.

Their efforts were fruitless and to this day, Nave’s house sits empty, bolted shut. Her cherished dogs now live with a neighbor.

But Kreklau could not forget about Nave. And neither could Maria Rodgers, 73, another friend. Rodgers and Kreklau didn’t know each other before the octogenarian disappeared but they bonded over their desire to find her—getting lunch and swapping notes, learning about investigative practices.

As time went on, they decided to formalize these brainstorming sessions, and in September organized the first monthly group meeting dedicated to Nave’s case.

“We just touch base with what we’ve got, what we’ve acquired,” Kreklau said.

“We also did a lot of research of our own into missing persons,” Rodgers told The Daily Beast. “I’m pretty sure that between the two of us, we have watched probably every 48 Hours or Dateline that involves a missing person, trying to educate ourselves as best we could.”

The last meeting drew six amateur sleuths, including Evelyn Cloy, 67; Traci Dickason, 53; and Dr. Judy Anderson. They don’t all know Nave personally but want to help a cause that hits close to home, Rodgers said.

"Everybody, I think, shares a sense of... ‘If I can do something here, it will be a good thing for not only myself, my family, my friends but the broader community,’” Rodgers said.

“ I’m pretty sure that between the two of us, we have watched probably every 48 Hours or Dateline that involves a missing person, trying to educate ourselves as best we could. ” — Maria Rodgers

They divvy up tasks based on interest and expertise.

“One of our core group, she loves maps,” Rodgers said. “She went to the county assessor’s and deeds office in Sumter.”

Another member, Rodgers said, is an expert in data management.

“Everything that we’re doing, where we think that it could be helpful down the road, we are recording and inserting into our database,” she said. “And that will be for not only us, but developing sort of a war chest of data—so we can find pieces of this puzzle that may fit.”

These golden-age gumshoes are also trying to develop sources at Continental Tire, a local manufacturing plant where Nave taught English to workers, Rodgers said. Another Continental Tire employee went missing the same year Nave did, she noted.

They reached out to the company’s human resources department and know the names of some employees they would like to contact.

They are also interviewing and re-interviewing some of Nave's neighbors and former employers and returning to places where missing posters were put up in 2017.

People who were contacted right after Nave went missing and had no useful information might now recall new details, Rodgers explained.

"What we're trying to do is either connect, or reconnect, with people who may or may not have information for us to establish a more detailed timeline of, at least, the few weeks or so leading up to our disappearance," she said.

While authorities have said there is no evidence of foul play, Rodgers hasn’t ruled it out in her mind and thinks it might be the best explanation for the disappearance “other than the alligator theory”—that is, the possibility that an alligator in the swamp near Nave’s house ate her.

“ That could have been my grandmother. That could have been my mother. ” — Sheriff's Investigator Charles Bonner

Investigator Charles Bonner, of the Sumter County Sheriff’s Office, told The Daily Beast Nave’s case is still an active investigation—and that given the lack of apparent foul play, she may still be alive.

“I still remain hopeful and want to keep a positive attitude about this,” said Bonner, who told the local TV station, WACH, that he keeps a picture of Nave on his desk. “That’s somebody’s family. That could have been my grandmother. That could have been my mother.”

He said investigators can’t rule out the “alligator theory” but the absence of clothing near the water undermines that premise. There also doesn’t appear to be a link between Nave’s disappearance and the other Continental Tire employee who went missing, he said.

Although law enforcement agencies are not known for their warm embrace of armchair detectives, Bonner welcomes the efforts of Nave’s friends.

“I wish we could all get along like this,” he said.

Kreklau said the group has no intention of giving up.

“One of the things that drives us is, given Barbara’s personality,” she said. “If it was one of us, we know she’d be doing the exact same thing.”