On a military barge in the middle of the Pacific Ocean, half a world away from his home in Baltimore, Wil S. Hylton felt ghosts.

"I got on this barge thinking I was going to do a magazine piece," says Hylton, who was on an assignment from GQ. "And I spent this time on the barge just feeling the presence of death and unanswered questions all around me. I'm not a religious person, I'm not even a spiritual person, I'm a born-again atheist, but the sense of ghosts in that place-whatever ghosts may be in your mind-were there."

Hylton's first book, Vanished: The Sixty-Year Search for the Missing Men of World War II (Riverhead), released this week, was born out of these ghosts. At the time, he had no idea that they would consume the next several years of his life. In fact, he really didn't even know what he was feeling, or why. Because nobody aboard the barge would tell him anything.

He was working on a story about JPAC (Joint Prisoners of War, Missing in Action Accounting Command), the military unit in charge of recovering lost soldiers from previous wars, or their remains. Given the nature of the missions, the secrecy was understandable-JPAC did not want to give false hope to families who have been waiting over half a century.

"At a fundamental level, it was the unit's job not just to bring home remains, but to provide each family with answers, in the hope that truth would allow life, finally, to go on," Hylton writes in Vanished. But if truth would allow life finally to go on, falsehood would jam up the cogs again. They had to be certain.

At first, this didn't bother Hylton. Initially, he thought of it as a procedural adventure story and planned to follow various JPAC team members from the barge off the coast of the tiny archipelago of Palau to the jungle of Peleliu and then all the way to Cambodia and Thailand.

But then everything changed.

"I got on the barge and I didn't want to leave, man," Hylton says. "There was something under the barge. All these incredibly talented disparate service members had come on this barge in the middle of the Pacific Ocean and they were down there exploring, and it was some kind of plane, and they were reading these moving emails, and I thought, I'm not leaving this story, this is the story right here. I've got to see this thing through."

Hylton, now a contributing writer to the New York Times Magazine, had reason to trust his gut. He's been a reporter virtually all his life. "I can clearly remember being a student at Roland Park Elementary, thinking it would be cool to get to high school because they would have a newspaper I could work on," he says. And when he started City College, he immediately found the editor of the paper, who asked him what he wanted to do. "I eventually want to do your job," Hylton told him.

By his junior year, he was doing the editor's job and, along with it, had an internship at The Evening Sun, which happened to fold when he was there, which was also the same time that The Sun faced its first round of buyouts. "All of a sudden there was no one around," he says. "There was this tiny community that were the leftover feature writers from the Accent section and the Today section, the two feature sections. And those of us who had been at The Evening Sun moved over to the Morning Sun and set up desks."

As a result of the vacuum, Hylton, though he was a high school student, was treated like a reporter and, he says, he essentially quit going to school. When it came time for college, he hated Kenyon-the small liberal arts college his father had attended-partly because "there was no newspaper. I loved being a reporter in Baltimore," he says. He eventually ended up in Albuquerque, N.M., where he still hated school but was able to write for the Albuquerque Tribune, which hired him on the strength of his Sun pieces. An avid outdoorsman, he spent a great deal of time in the wilderness, married his high school sweetheart, whom he became reacquainted with out West, had children, and began to write for magazines like Rolling Stone, Harper's, and GQ, the magazine that had sent him to the small Pacific archipelago of Palau.

And everything he'd learned in a lifetime of reporting told him the story was here. Eric Emery, the "rumpled archaeologist . . . with deep lines etched around his eyes, his beard at least a week grown in, his hair an unruly explosion of wire" who was in charge of the mission, had made it clear to Hylton that he was tolerated but not exactly welcome, answering questions with as few words as possible.

So Hylton got on a satellite phone with JPAC's public affairs officer and started raising hell. "I told them, 'I need to just focus on one of these. I'm not going to Peleliu, the jungle; I'm not going to Cambodia and Laos and all these other places,'" Hylton recalls. "'That's not the way I see story. I'm not going to do some round up. I want to dig down someplace. All these guys are going underwater and doing something and I don't even know what it is.' So I was kind of pissed they wouldn't let me go see it."

After his loud phone calls, everyone on the boat sensed the frustration that was eating at Hylton, who is a certified scuba diver and was insistent that he could dive down with Navy divers to see what was under the water there. "Maybe I was being a little bit of a prima donna," he admits. "But I felt like it was my responsibility as a reporter to push. And I lost. They said 'no,' and I had nowhere else to go. I had no other recourse to get down there. The coordinates aren't even publicly available, so I couldn't wait until there was a day off and go find it."

At this point, Hylton was resigned to returning home, writing his procedural story, and allowing all that he didn't know about what was under the barge to serve as a metaphor for what we didn't know about the many men lost in the Pacific during World War II, which, as it turns out, is 47,000 men-about the same number as the total combat casualties in Vietnam.

But the story would not let him go. His first breakthrough came from the most unexpected source. One of the medical doctors aboard the ship had appeared the previous year on the reality television show The Bachelor, which had initially caused Hylton to shy away from him. But it quickly became apparent that "Doc" Andy Baldwin was more than just a pretty face.

"If he had a down minute, he would grab a broom and sweep up," Hylton says of Baldwin. "He ended up spending as much time underwater, doing the grunt work and suctioning sand off the bottom in these huge suits and hard hats. He was always down there, didn't have to be. And in the evening, he'd go out for these epic runs through the islands, and then on days off, he would go and treat island children. He was just this absurd good samaritan-type personality, and I grew to really like him and completely forgot about the chips I had against him for being a reality star."

Recognizing Hylton's frustration, Baldwin approached him and said that even though JPAC would not let them scuba dive in the area, they couldn't-or weren't going to-keep them from swimming. Doc said he would take Hylton free diving, or, as Baldwin put it "breath-hold diving." So Hylton borrowed a mask and flippers and stripped down to his underwear and went out into the water with the Bachelor.

"We jumped in the water, man, and I was scared out of my wits," recalls Hylton. "I have done plenty of snorkeling, but the most shallow part [of the wreck] was 30 or 40 feet and the deepest part was about 70 feet, so getting down to that depth involves holding your breath for a minute or something."