I'm lying in a bark hut surrounded by strange men. One sits smoking pungent tobacco rolled into a long, fat spear, a caricature of a Rastaman's joint. Two others chew betel nut, their mouths a bright, frothy red. Curled up in the corner, my friend George Houde is sleeping the sleep of the dead while rats play at his feet.

In October 1942, during a march considered one of the cruelest in modern military history, 1,200 ill-equipped, untrained American troops from the 32nd Infantry Division endured more than a month of suffering on the Kapa Kapa en route to the north-coast battlefields at Buna, where the Imperial Japanese Army was waiting. At least two men died of exhaustion during the crossing, and the rest were physically shattered by the trek. Remarkably, after nine weeks of fighting in stinking, hip-deep swamps full of floating corpses bloated by the heat, the Allied troops finally dislodged the Japanese from Buna. But the victory came at a cost. According to General Robert Eichelberger, the commanding officer, fatalities "closely approached, percentage-wise, the heaviest losses in our own Civil War battles."

The soldiers' memories are still searing. "If I owned New Guinea and I owned Hell, I would live in Hell and rent out New Guinea," says Buna veteran Bob Hartman.

I'm beginning to see what he means. Three years ago, while researching a book on the soldiers' experience, I hatched the idea of repeating the WWII march. If the trek succeeds, it will be the first time in 64 years that a team from outside Papua New Guinea has hiked the trail in its entirety. I'd visited New Guinea four previous times, the last trip just ten months ago, when I came to scout the area. I was advised then by former Australian colonial patrolmen, the Papua New Guinea Defense Force, and a number of trekkers familiar with the New Guinea bush not to attempt the crossing. Even if the route had not been consumed by jungle or erased by torrential rains, I was told, it was at best nothing more than a narrow hunting-and-trading trail that traversed some of the country's most formidable territory. One villager looked into the mountains and whistled through his teeth, "Long way too much." A former government patrolman challenged my sanity. "You're delusional," he said.

The Australians had counseled General Douglas MacArthur against sending men on this route, too—the mountain passes were too high, the terrain too rough, the rivers too fast, the tribes unpredictable.

But they went, and now so have I. The sun drifts below the mountains, and the evening is stifling. Dela, the hut's owner, inexplicably refuses to prop open the thin bamboo boards that serve as windows. When I persist, he explains in a mix of English and Motu that there are sorcerers who roam the hills at night, cast deadly spells, and will try to kill me. Just then I hear soft voices outside the hut. Dela opens the door and villagers file in with bowed heads, as if in prayer. They begin to sing, in two-, three-, four-part harmony. It's as if angels have descended.

Perhaps our luck is turning, I think. The next morning, George and I walk out of Dela's village to a rutted road and jump in the back of a truck. After a series of bone-jostling rides we arrive back in Port Moresby, Papua New Guinea's capital city, where I buy anti-inflammatories and painkillers and plot with George about how we can continue the trek. Could we meet up with the rest of our group by plane? "Impossible," a pilot we approach tells us. With a helicopter, though, he thinks we stand a chance.

Seventy-two hours later, as we hover in a chopper over a vast jungle canopy broken only by rivers spilling out of murky mountains, the sight of so much raw wilderness has me second-guessing my decision. I've never seen the likes of the Kapa Kapa Trail.