It's hard to think that the slave trade exists today. But it does. It exists in the form of human trafficking.
"I think Americans would be shocked to find out that there is slavery in America today," says David Blood, director of NGO Winrock International in Moldova. "There is trafficking. It does happen. It happens in our own cities. Americans who have no idea have probably met young women who have been trafficked."
The U.S. government estimates between 600,000 and 800,000 people are being trafficked each year from 127 countries. Moldova is one of them and has been identified as the source of much of Europe's human trafficking.
Most often, the victims are women and children headed to the Middle East and other European countries. They often become slaves forced into the sex trade.
What is human trafficking? According to Blood, it is, ''the forced exploitation of individuals, forced to work. When you talk about the work being forced, it's not necessarily physical force, it could be through threats or violence, threats of reprisals against the individual who has been trafficked providing sexual or other services.
"It could be through threats or reprisals against their family," he adds. "It's very typical scenario when a young woman is told that, 'We know where you're from, we know where you live, we know where your parents are, and we will kill them. If you try to run away, if you don't service this client, if you don't have sex with these 10 men today, then we will harm or we will kill you or your family.'"
Some say trafficking has reached epidemic proportions, that it's a $42.5 billion illegal industry for the traffickers, so the rewards are high.
In the tiny poor country of Moldova, in the furthest corner of Eastern Europe, the average salary for a Moldovan is less than $100 a month. In the villages it's even less. It's no surprise that many girls dream of a better future. But these dreams can turn into nightmares.
Nadia is a victim. When ABC News filmed her, she didn't want her face shown. Four years ago, she left her home in search of better opportunities. Instead, she was lured into a trap by a criminal gang that held against her will. Nadia became a slave.
"I was taken to a house where I was told I had to become a prostitute," she says. "I didn't want to do it. I was only 14 years old."
Her story is like other victims'. Nadia said her captives beat her until her jaw was broken. But she didn't dare to leave, even as her profits were taken, because of threats against her family.
"I was sold several times," she said. "I was living in a basement. There was always a huge line of clients and I couldn't service them all."
Nadia was lucky; a young client took pity on her and helped her escape. She now is staying in a shelter for trafficked victims where she can get psychological care and a temporary place to stay.
Most victims can't return home. Because of the stigma attached to prostitution, many are rejected by their families. More than 90 percent of them need medical and psychological treatment for insomnia, nightmares and suicide attempts.
As many as 5,000 Moldovan women are duped into slavery each year. Twenty five percent of Moldova's four million population travel overseas in search of better wages.