Riding the Seoul Train.

Ho's long road to freedom began atop a mountain of French trash. Back in 1993, when Pyongyang tried to raise foreign exchange by taking in French garbage for $200 a ton, a curious Ho joined college buddies in combing through the refuse. They found a videotape. "A lot of people chatting in a foreign language," Ho says. "We were arrested for watching it." The punishment--three months in a re-education camp-- shattered Ho's faith in the North Korean regime. Branded a "hooligan," he turned to the black market when famine swept the country in 1996. He was arrested again, this time for smuggling antique pottery, and sent to a koppaku ("reform through labor") camp 150 kilometers south of the Chinese border. Guards "beat me like an animal," he says. He survived (minus nine teeth), and in 1999 escaped into China across the frozen Tumen River.

That was only the start of his journey. In China Ho barely avoided being nabbed in a sweep for undocumented immigrants. After saving $50 from working in a factory that produced karaoke machines, he bought the cheapest ticket he could and, with the help of his rudimentary Chinese, headed south as far as Vietnam. He crossed the border on foot, dressed in rags and applied for asylum at the South Korean Embassy in Hanoi. But, he says, "they told me, 'This is a communist country, so we can't help you here. Go to Thailand'." A sympathetic diplomat slipped him $100; in Ho Chi Minh City, South Korean missionaries offered more cash and guidance. Ho, pretending to be a deaf-mute and occasionally shouting "Korea!" to see if anyone spoke his language, trekked across mine-strewn Cambodia. Finally, after almost three months on the road, he staggered into Bangkok. South Korean diplomats there granted him asylum.

Ho's itinerary might seem outlandish: the resourceful 33-year-old traveled more than 5,000km to cross the 198km between Pyongyang and Seoul. But more and more refugees are following equally roundabout paths from North to South Korea. They're hiding in Siberia, hiking the Burmese highlands, wandering the Mongolian steppes during the fiercest winter in half a century. Ragged asylum-seekers like Ho now trickle into Seoul at the rate of roughly three per day from as far afield as Copenhagen, Dubai, Ulan Bator and Moscow. "We even thought of taking them through Tibet," says one of those who help sustain the underground railroad. "But we decided they'd be too weak to endure the altitude." This year, more than a thousand North Koreans could land up in Seoul, about as many as have arrived since the end of the Korean War.

In a four-month investigation, News-week explored this clandestine network drawing North Koreans to the South. From the Tumen River, its paths extend throughout Asia, Central Asia, Russia, even as far as Western Europe. More than 60 organizations and individual activists, and several thousand collaborators, are involved. Participants include Buddhist and Christian charities, underground missionaries, profit- seeking middlemen, crooked cops and--beyond China's borders--Japanese housewives, Burmese rebels, right-wing South Korean politicians and diplomats in at least nine countries. Depending on route and comfort level, a ride on the Seoul Train can take anywhere from a month to a year and cost upwards of $3,000.

Not many North Koreans have the money or stamina necessary to make these often-grueling journeys. But the fact that thousands are desperate enough to try bodes ill for Pyongyang. Whereas most North Koreans once sought food in China to bring back home, many now view their departures as permanent, and hope, after amassing the necessary capital in China, to seek asylum in South Korea. Already, an estimated 300,000 refugees live in villages and cities scattered across northeast China, where they are periodically rounded up and deported in what human-rights activists decry as a clear violation of the 1951 Geneva Convention. Aid agencies warn that thousands more may join them this spring--by Pyongyang's own admission, the greatest number since 1997-- when last year's dismal harvest runs out.

The Seoul-based Commission to Help North Korean Refugees (CNKR), the largest organization dedicated to assisting asylum-seekers, has collected nearly 10 million signatures on a petition to the United Nations demanding refugee status for North Koreans who have fled to China. The group plans to present the document to the U.N. General Assembly in New York next month. Sam Rho, a leading figure in CNKR, acknowledges that the appearance of refugee camps in China might trigger a huge exodus. "That is our objective," he says. "If many refugees escape, then North Korea will be crushed like an Easter egg."

ON THE BORDER