She makes her way from store to store, clutching photocopied snapshots of the daughter she can't find. A pizza place, a shoe store, a Dunkin' Donuts—Beth Twitty keeps moving, polite but utterly relentless in her search. "Hi, I'm Natalee's mom," she says, her blond hair pulled back in a bun, her eyes hidden behind sunglasses. "Can I leave a flyer?" So far she has taped hundreds of flyers to the windows of stores across Aruba—feeling on some days that it could make a difference, and on others like it won't. On this day, June 17, she woke up thinking, "Today will be the day," but by nightfall her daughter Natalee Holloway had yet to be found. "I don't give myself a timetable," she said later, "because I'm disappointed when nothing happens."

Beth has been fighting disappointment for more than three weeks now, starting just a few hours after Natalee, 18, failed to show up on May 30 for the plane trip home from Aruba, where she and 124 high school classmates from Mountain Brook, Ala., were on a five-day vacation. Natalee's disappearance has led to massive island-wide searches involving FBI agents, Dutch Marines and hundreds of Aruban civil servants. It also triggered a problematic police investigation that—after the arrest and release of two former hotel security guards—finally focused on the man Natalee's family has believed all along holds the key to the mystery: Joran van der Sloot, 17, who along with two friends was seen giving Natalee a ride the night she vanished.

Van der Sloot, the son of a local judge, Paul, is now in police custody, as are his friends—brothers Deepak Kalpoe, 21, and Satish Kalpoe, 19, the sons of a prominent Aruban businessman. On June 17 a fourth man was arrested: Steve Gregory Croes, 26, a disc jockey on a party boat. (PEOPLE attempted repeatedly to reach attorneys for all four men for comment, but the calls were not returned.) The sluggish pace of the investigation (see box) frustrates Beth, 45, who despite her patient demeanor—she has taught disabled children for 21 years—cannot always contain her anger. "I have to have answers, and I better get them soon," she says, her voice rising. "The bottom line is I expect to see results. And that means they better find her."

But finding Natalee is not something her loved ones have left solely to others. Literally seconds after learning she was missing, Beth began mobilizing her family into a remarkably nimble search-and-investigation team—a team that was far quicker than Aruban police in developing leads. She and her second husband, Jug, 49, a manager for a metal-sales company, have been in Aruba since May 30, scouring the island's harsh terrain and fanning the embers of hope among the scores of friends and relatives who have traveled there to find Natalee. "We're not naive," says Robin Holloway, 40, who with her husband—Natalee's father, Dave Holloway, 45—has been in Aruba for more than two weeks. "But in my mind, I can't picture her anything but alive."

Nor is Beth content to wait for Aruban investigators to get answers. On June 21, while handing out prayer cards, she saw Paul van der Sloot outside his home and called out to him. Invited inside, she spent 90 minutes pressing him for information and left convinced that he is holding something back. "It was just a personal conversation, but when I have a conversation, I usually have a goal in mind," she says. "He gave me confirmation of my feeling that there is additional information that needs to be investigated in regard to my daughter's kidnapping."

Beth's nightmare began with a cellphone call around 11 a.m. on May 30. One of the seven adult chaperones on the Aruban trip was calling with news that Natalee was missing. Beth, driving home to Birmingham with two friends after a vacation in Hot Springs, Ark., stayed calm but dialed 911 to ask for a police escort to get her home quickly. When she didn't get one, she kept driving fast anyway: A state trooper pulled her over doing 110 mph. "I got out of the car before he could get out of his," says Beth, who explained the situation and persuaded the trooper to get her the number of the FBI. "There wasn't even a tiny second when she didn't know what she was going to do," says her friend Marilyn Whitlock, who was in the car. "She was completely calm and in charge."

Within hours her family had drawn the FBI into the case, secured a private plane to fly them to Aruba and, incredibly, got a lead on the young man Natalee was with before she vanished. Jug spoke with Natalee's cousins Thomas and Hunter, 18-year-old twins who were on the trip, and learned that Thomas had played poker with the same young man at the Holiday Inn casino earlier that night. By 5:30 p.m. on May 30, the Twittys were en route to Aruba, arriving at 11 p.m. Their first meeting was with FBI agent Eric Williams, who was already on the island. "I wanted to make sure he knew we were dealing with something way more than someone who might have overslept," says Beth, who described her daughter as mature and conscientious (see box). "I felt it was my duty to make them realize the seriousness of it."

Next, the Twittys got the Holiday Inn manager to pull video footage from the casino; thanks to Thomas's description, they spotted Joran van der Sloot on the tape. With the help of some locals, they soon found van der Sloot's full name and address. Beth's first thought: "I'm going to his house. I'm going to get her. He has her." It was 2 a.m.

After alerting Aruban police, they drove to the van der Sloots' orange stucco home in Noord. Police accompanied Joran and his father, Paul, to the Holiday Inn, where the conversation continued. Joran admitted he had been with Natalee that night, but his father—who did not return PEOPLE's calls for comment—"kept telling him not to say anything," says Jug, who listened in on the interview. Then, an extraordinary confrontation: Beth, waiting in the van, noticed Joran and his father heading toward her. Holding Natalee's senior class photo, she spoke directly to Joran. "I want my daughter back," she told him. "He had the most arrogant, condescending, disgusting response," says Beth." 'What do you want me to do?' He kept throwing his head back and hitting his chest. I felt like he had her or he knew what he did with her."

But Aruban police did not detain Joran or his friends; instead, on June 5, they arrested Mickey John, 30, and Abraham Jones, 28, two former hotel security guards described to them by the three young men. John and Jones were held for eight days before being released. "I was trying to clear my name, but they wouldn't listen because of what those boys said about us," says John, who was still in jail when Joran and his friends were arrested June 9. Deepak Kalpoe was given the cell next to him, but since they could not see each other, "he didn't know I was one of the guards he had lied about," says John. John claims Kalpoe told him he made up the story about dropping Natalee off at the Holiday Inn where she was staying. Instead, he and his brother dropped Joran and Natalee off near a different hotel, the Marriott, before going home. Around 3 a.m. that night, Kalpoe got a text message from Joran "saying that they needed to talk," says John. Joran never called him, but still Kalpoe "was very upset," claims John. "He said he should have never left the girl alone with the Dutch boy."

The portrait that emerges of Joran van der Sloot—an honor roll student and star athlete at the International School of Aruba—is of a popular teenager who "liked to party," says Kimberly Boekhout, a regular in the same social circles. "But he only wanted to party with American tourists. He liked girls with blond hair." Sjona Vrolijk, who knows him from the bar scene, says, "He has a funny personality that makes people like to be around him. And when he found a girl, he'd move very fast."

Beth, meanwhile, felt such a sense of urgency after landing in Aruba that she did not sleep for 48 hours. Exhausted but too worried about Natalee to shut down, she took a cab to a chapel on Aruba's north end at 5 a.m. on June 1. There she walked in the morning's dim light along a row of 13 shoulder-high white crosses. Suddenly "I realized God was taking care of Natalee," she says, "and so I could just focus on finding her."

Searching Aruba's desolate brush has been nerve-racking work. "There were so many times when we smelled something horrible and you think, 'Please, don't let it be her,' " says Robin Holloway. "And then you'd find a dead dog or chicken." On June 10 FBI agents gathered Natalee's family to brief them on the arrests of Joran and his friends. They offered no details but conveyed "that the investigation appears to be of foul play," says Dave, "and that there's a possibility that Natalee may not be found alive."

Beth took the briefing in stride, resuming her mission to put her daughter's photo in every store in Aruba. Her demeanor is upbeat, though in rare unguarded moments she fights back tears when talking about Natalee. At night she sleeps in a wrinkled nightshirt that she fished out of Natalee's dirty laundry in Aruba because it makes her feel close to her daughter. And at least once a day she retreats to the chapel that gave her solace early in her journey. She stares at the sea and feels Natalee's presence in the hillside winds. Sometimes it is there, in the most peaceful of places, that the reality other situation hits her the hardest. "All I've been saying since day one is I want answers," she says, "and now I don't know if I can handle the answers."

But then somehow she finds the strength to go on. The Twittys are humbled that the fathers of 12 of Natalee's classmates have joined them in Aruba; some of the men have lost as many as 20 lbs. walking the island. Still, they realize that soon most of the searchers will have to go home. Beth, though, will not leave Aruba without her daughter. When she first got there, she went to Room 7114 at the Holiday Inn—Natalee's room. It was a first-floor room with two double beds and a sliding glass door that opened onto white sand. Beth and Jug decided to move into the room themselves, and that's where they remain. In the corner there is a floor lamp that Beth found switched on when she arrived. Now it is the lamp that she never, ever turns off. "Because that's what parents do," she says softly. "You leave the light on, waiting for your child to come home."

Alex Tresniowski. Jeff Truesdell and Steve Helling in Aruba, John Anderson in Mountain Brook and Siobhan Morrissey in Miami

  • Contributors:
  • Jeff Truesdell,
  • Steve Helling,
  • John Anderson,
  • Siobhan Morrissey.