When shards of bone were discovered in Aruba a few years ago, Dave Holloway hoped against hope that DNA testing would prove the remains were of his daughter, Natalee Holloway, who went missing in 2005 while on a high school graduation trip to the Caribbean island.

It would be sad, and it would be disturbing, but at least it would be an answer in a case that remains largely composed of questions.

It took a year and a half of working under the radar with the help of an informant to locate the spot where the remains were found, behind a house that had been previously mentioned over the course of the sporadically eventful investigation.

“We’ve had a number of disappointments and I’ve put up a wall trying to find something that’s not gonna disappoint me,” Holloway said on Today in August 2017. “And when we determined that these remains were human, I was shocked, and I know that there’s a possibility this could be someone else, and I’m just trying to wait and see.”

But that October it was revealed that the mitochondrial DNA wasn’t a match to a sample provided by Natalee’s mother, Beth Holloway. The bones didn’t belong to Natalee.

Another dead end.

“Out of the four individual bone samples only one was found to be human,” forensic scientist Jason Kolowski, who tested the samples, explained to Oxygen, which chronicled Dave Holloway’s journey with private investigator T.J. Ward as they followed what felt at the time to be their most promising lead in years.

“We don’t know if the person is male or female,” Kolowski added. “We don’t know how old that person is. We don’t know how long that person has been dead.”

For the past 15 years, the investigation into Holloway’s disappearance has carried on in fits and spurts, with light occasionally appearing at the end of the tunnel, only to be snuffed out at the first whiff of closure. In the meantime, books have been written, Lifetime made two movies about the case, news-magazine shows have covered it top to bottom, and every theory in the book has been floated—including that Natalee is still alive, or at least was for years after the events of May 30, 2005, transpired.

Whatever those events were, exactly.

Despite all the media attention and so many law-enforcement hours spent trying to find out what happened, definitive answers have remained out of reach. But numerous times, authorities and Natalee’s family seemed to be getting closer.

“We always felt like with every lead, with every tip, it was always as if we were about to get her,” Beth Holloway told 20/20 last summer. “They just always turned up nothing.”

Natalee’s mother returned to Aruba in 2019, where she reunited with one of the locals who helped search for her daughter in 2005—and also relived the most harrowing weeks of her life.

“She said, ‘I came to see my daughter, I’m not leaving without my daughter,'” remembered Alberto Groeneveldt, who served as a guide for Beth and the friends who had come from Alabama after they met at the airport upon arrival. “What every mother would do.”