Natalee Holloway's mother on her nearly 15-year journey to find out what happened to her daughter in Aruba

Roughly 24 hours after her teenage daughter Natalee Holloway vanished in 2005, Beth Holloway stood face to face on a foreign island with the man she believes holds all the answers to what happened to her daughter – Joran van der Sloot.

“I thought, ‘You're it,’” Beth Holloway told “20/20” in an exclusive interview this summer. “Did I know what was to come? No. But I knew that I was gonna hang onto him 'til my last breath.”

Natalee Holloway, an 18-year-old from Alabama, was in Aruba celebrating her high school graduation with members of her senior class when she disappeared.

She was last seen on May 30, 2005, leaving a bar called Carlos’n Charlie's in Oranjestad and getting in a grey Honda with van der Sloot, a Dutch national who was 17 at the time, and two of his friends.

Van der Sloot is now serving a 28-year prison sentence in Peru for a different crime. He has never been charged in connection to Natalee Holloway's disappearance.

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

*Watch the full story on "20/20" FRIDAY at 9 p.m. ET*

It’s now been nearly 15 years since her daughter disappeared. She has never been found.

Beth Holloway has fought for years to find out what happened to her daughter and “20/20” exclusively documented her emotional return to the island this summer.

Searching for Natalee Holloway in Aruba

Upon learning of her daughter's disappearance, Beth Holloway immediately flew from her home in Alabama to Aruba. There, she, as well as others from Alabama, Natalee’s father, local police, and Aruban locals spent days in massive searches for the young woman.

Surveillance footage from a casino adjacent to Natalee Holloway’s hotel showed her seated at the same blackjack table where van der Sloot was sitting. The footage was taken hours before Natalee Holloway was seen leaving the Carlos’n Charlie's bar with him.

A few hours after Beth Holloway arrived on the island, Aruban police officials accompanied her and other Alabama parents on a visit to the van der Sloot home to ask about Natalee Holloway. The grey Honda she was last seen getting into was parked outside.

“Deepak Kalpoe and Joran van der Sloot are standing out in the gravel driveway,” Beth Holloway said.

There, Joran van der Sloot told Beth Holloway the night her daughter went missing he had fooled around with her, then returned her to her hotel, a Holiday Inn.

It was the first of many stories he told, and the first to prove a lie. Surveillance footage from the hotel showed no evidence that Natalee had returned to the hotel that night.

Beth Holloway still had no idea the journey that was ahead of her.

“I found this taxi and I asked him to take me somewhere I could pray. He took me to the other side of the island,” Holloway remembered. “There was a small beautiful little chapel, Alto Vista Chapel, that was sitting on the hillside overlooking the sea. And I walked up to the cross and just fell to my knees.”

“This is the only place on the island where I could come to feel close to Natalee,” she said. “If I had not had found such peace on this island, I could have never done the work that was before me.”

More than a week after Natalee Holloway's disappearance, van der Sloot and his two friends, brothers Deepak Kalpoe and Satish Kalpoe, were taken into police custody.

Van der Sloot and the Kalpoes then changed their stories and claimed the brothers had dropped van der Sloot and Holloway off at the beach. Joran said he later left a sleeping Natalee alone at the beach.

In the following weeks, Beth Holloway joined journalist Greta Van Susteren, who was reporting on the case from the island, for an interview without cameras with van der Sloot’s parents at their home. Holloway said van der Sloot's father, Paulus van der Sloot, invited them in.

“I wanted to be that close to Paulus van der Sloot,” Holloway said. “I wanted to make him feel in some way how I was feeling.”

“Beth was stern and direct,” Van Susteren said. “Anita, Joran's mother, was crying, sobbing.”

“Paulus, who was sitting next to me, was perspiring like something I have never seen in my life,” Van Susteren continued. “I assume that there are medical reasons people perspire like that. But there's also the suspicion that someone who's perspiring like that knows something.”

About that exchange, Beth Holloway said she thought Paulus van der Sloot was “the most pathetic human being I’ve ever seen.”

“Because he knows what happened. He knew,” she added.

Beth Holloway continued making media appearances to keep the pressure on authorities to solve the case. The story was dominating headlines around the world and Beth Holloway said at the time, she did a dozen interviews a day.

“Mic and sit and talk,” she said. “I mean, that's all you could do.”

Early in the search, she told ABC News’ Deborah Roberts in 2005 she would not entertain the possibility that her daughter wouldn't be found, saying at the time: “That’s not an option.”

“Without the media's constant presence there, Aruba would have just swept this under the rug,” she said in "20/20's" 2019 interview.

She said public support for her changed after Deepak Kalpoe and Satish Kalpoe were released from police detention and she made a desperate plea.

“It is now that I ask the world to help me,” Holloway said at a July 5, 2005 press conference. “Two suspects were released yesterday who were involved in a violent crime against my daughter. Help me by not allowing these two to get away with this crime.”

It was after that press conference, she said, that "the island turned on me."

“All the people that were helping, all the people that I felt we were working together," Holloway said. "You could feel the tide turn. It was not okay for me to call their citizens criminals.”

The Kalpoe brothers have never been charged in connection to Natalee Holloway's disappearance.

Then, in late August 2005, the international media attention on Natalee Holloway’s case turned to the devastation of Hurricane Katrina in the United States. The lull in media coverage of her disappearance also coincided with van der Sloot’s release from police custody because Holloway’s body had not been found and authorities did not have enough evidence to charge him.

“He's a monster. I know that he was responsible for the demise of Natalee. And I'll never, never not believe that,” Beth Holloway said. “I made a pledge that I will share everything that I have learned. So, that's what I did.”

Back in the U.S., Beth continued her media circuit. Holloway appeared on Dr. Phil’s talk show where he called on Americans to boycott Aruba.

“Our sole bread and butter is tourism,” said Alberto Groeneveldt, an Aruban who helped guide Beth Holloway in the search for her daughter. “A lot of flights start to cancel. Of course, the tourism went down.”

“I was trying to destroy an island and Joran, so I was on a mission. They destroyed me, and I thought, ‘Well, I'm going after them,’” she said.

Joran van der Sloot’s story changes again and again

As the years went on, Joran van der Sloot’s story about what he says happened to Natalee Holloway continued to change.

By 2006, van der Sloot was in the Netherlands for school. In February 2006, he flew to New York for an interview with ABC News, during which he said he left Natalee Holloway on the beach the night she disappeared and went home.

“The last time I saw her, she was sitting on the sand by the ocean,” he told ABC News at the time. He denied that he had harmed or killed her.

In February 2008, Aruban officials reopened the case against van der Sloot after a tape showing him describing Holloway’s death, filmed via hidden camera by Dutch crime reporter Peter de Vries, was released.

However, Aruban officials were unable to corroborate van der Sloot's statements.

Then, in November 2008, Greta Van Susteren got an interview with van der Sloot in Thailand, during which he claimed he had sold Natalee Holloway into sexual slavery. But soon after, he called Van Susteren and told her that story was all a lie.

On March 29, 2010, Beth Holloway’s lawyer, John Q. Kelly says that van der Sloot contacted him by email using a pseudonym, claiming that in exchange for $250,000 -- $25,000 up front -- he would reveal the location of Natalee Holloway’s remains.

“Joran's a gambler and that's probably the most important thing to know about him,” Kelly told “20/20.” “Everything in life is a gamble and a game to him.”

But Kelly and Beth Holloway believed this might provide them with an opportunity to get the justice they sought against van der Sloot.

“I thought, ‘OK, so he wants $250,000 trying to sell me her remains,’ as sick and cruel as that sounds,” she said. “What can we do with this?"

They worked with the FBI to gather evidence against van der Sloot for possible wire fraud and extortion. Kelly says the FBI went down to Aruba to set up recording devices in a hotel room where he was to meet van der Sloot.

When Kelly met with him, he said he gave van der Sloot $10,000 in cash and Beth Holloway wired $15,000 to van der Sloot’s bank account in exchange for information van der Sloot said he had on the missing teen.

Kelly says van der Sloot then took him to a location away from the hotel and changed his story again about the night he had been with Natalee Holloway.

He now claimed that he had picked her up but that she had demanded to be put down, so he threw her to the ground. He said when he did, her head hit a rock and she was killed instantly by the impact.

Kelly says Joran then took him to a nearby home and claimed that his father, who had since died, had buried Natalee in the house’s foundation.

After that exchange and they parted ways, Kelly says van der Sloot emailed him and told him that story was all a lie -- a message which Kelly forwarded to the FBI.

But van der Sloot already had the $25,000 from Beth Holloway. Within days, van der Sloot had slipped away to Peru.

“I thought, ‘What the f--- is he doin' in Peru? Why isn't he arrested?’” Beth Holloway said.

The FBI declined to comment to ABC News on Wednesday.

But in 2010, the FBI said in a statement that the Holloway “investigation was not related in any way to the murder in Peru. Despite having been in motion for several weeks … it was not sufficiently developed to bring charges prior to the time van der Sloot left Aruba."

The lack of an arrest in the extortion case, the FBI said at the time, "is not due to any fault on the part of the FBI or the U.S. Attorney's Office."

Van der Sloot murders Stephany Flores

On May 30, 2010 – five years to the day of Natalee Holloway’s disappearance -- Stephany Flores, a university student and daughter of a presidential candidate, was found beaten to death in a hotel room rented by van der Sloot in Lima, Peru.

“Some people have said, ‘Well, you know, Beth, if you hadn't sent him that $25,000 he probably wouldn't have had the money to go to Peru and then kill Stephany.’ Well, hell no. I did everything I knew to do,” Beth Holloway said. “Whoever was responsible for letting Joran leave that island, Aruba – they are the ones that have to sleep at night over Stephany Flores' death. Not me.”

In the three days before Flores’ body was discovered, van der Sloot was able to cross the border into Chile. An international manhunt was launched, and based on a tip given to authorities, he was arrested in Chile.

On that same day, U.S. federal prosecutors announced wire and extortion charges against van der Sloot “for soliciting money from Natalee Holloway’s mother on promises he would reveal the location of her daughter’s remains in Aruba and the circumstances of her 2005 death.”

Meanwhile, van der Sloot was sent back to Lima, where according to the local prosecutor, he admitted to everything -- how he beat Flores, took her money, and then fled with her belongings.

Beth Holloway decided to fly to Peru in the wake of Flores’ murder.

“I wanted to go to Peru to meet with Stephany's family,” Holloway said. “The Flores family and I, we share this same bond… It’s not a bond you want, but it’s a bond that exists.”

She also went to see van der Sloot in prison while he was awaiting trial for Flores’ murder. It was the first time she had seen him since the day her daughter vanished five years earlier.

“I walked through by myself with all the girlfriends and mothers and lovers who were standing in line for that visitation day,” she remembered. “One of the wardens there took me in his office. And then we set up the meeting with Joran.”

Face to face with van der Sloot again, Holloway asked him once more to tell her what happened to her daughter.

"Let me take her home," Holloway told him.

Van der Sloot told the grieving mother, “I’ve had a lot of time here to really think. I really do want to write you. I need some time to think about what I want to say.”

Despite not learning the whereabouts of her daughter’s remains, Holloway said it was “glorious” to see him in prison, “Where I wanted him to have been five years ago.”

In 2012, van der Sloot pleaded guilty to Flores' murder and was given 28 years behind bars -- a sentence he is currently serving in Peru’s prison system.

“Is it the justice I wanted? No, but it’s the justice I’ll take,” said Holloway, who is still waiting for an answer.

In March 2014, it was announced van der Sloot will be extradited to the U.S. after he finishes his sentence in Peru.

Aruban prosecutor Hans Klaver told ABC News recently that his office has never closed the Natalee Holloway case.

However, “the cases against Joran van der Sloot and the Kalpoe brothers have been dismissed. Only new facts and circumstances unknown at the moment of the dismissal can lead to reopening their cases."

Beth Holloway returns to Aruba

It's been fourteen years since her daughter disappeared, and Beth Holloway said the island “has become a lot less significant” for her.

“I have come to the terms that this island doesn't hold anything over me anymore,” she said.

Upon her return this summer to the island, she reunited with Groeneveldt, who helped her in the initial search for her daughter.

Beth Holloway told him it was the “the first time today I've been really able to just look at the ocean, enjoy the ocean and feel it and just sit on the beach.”

“Every time I looked out at the ocean, I couldn’t handle it. It just disturbed me greatly. Because it made me feel as if I was never going to get an answer as to what happened to Natalee,” she said. “But I feel like I have accomplished a huge feat… I can come back now to Aruba. I can get in the water... It feels great.”

Today, van der Sloot is still being held in Peru and will be eligible for parole before his sentence is finished.

Beth Holloway said she keeps her daughter's senior portrait in her bedroom.

“Every morning I go give her a kiss on the cheek, trace my hands down the rosary beads and across and just say a prayer. Some days I'll say, ‘What are we doin' today, Natalee?’ and ‘Let's do this today.’ So I feel like she's still a team with me,” she added. “She was always a driving force, so she’s been with me all the way.”

“You’re never going to get over the loss of losing your loved one- that’s not going to happen. But life does move on,” Holloway said. “Natalee would want us to enjoy what life we have left.”