This article is part two of a five-part series titled "The Business of Illicit Massage." Parts one, three, four and five are also available online.

The recently arrived Chinese immigrant living in New York City was attracted by a Chinese-language ad for massage therapists that read, “no experience necessary.”

She thought her financial woes would be solved, but instead she said she met a group of traffickers who took her passport and put her in a car, not telling her where she was headed.

“I had no idea where I was going,” she said. “And after I got there, they forced me to do sex work.”

The woman, who requested anonymity to detail her story, is one of an estimated 25,000 women working in illicit massage businesses throughout the United States, according to a recent report by an anti-trafficking organization. While some may be willing participants, advocates and law enforcement say many are being held against their will, forced to work because of huge debts, fear and shame.

Violence is pervasive, researchers say. And victims often are reluctant to tell their stories.

“They are so vulnerable, many of them," said Massachusetts Attorney General Maura Healey. "Most of them do not speak English, and are subject to really brutal and awful treatment."

Women work in an estimated 185 illicit massage businesses in Massachusetts, according to Praesidium Partners, a Virginia based anti-trafficking organization.

State police just this week on Tuesday arrested two people on human trafficking charges, following a raid on two massage parlors in Springfield. Steven C. Forsley, 65, of Bernardston, and Liu Yang, 61, of Springfield, pleaded not guilty to charges that include trafficking of persons for sexual servitude. 

WGBH News and the New England Center for Investigative Reporting found significant numbers of women — undocumented and usually broke — are likely working in facilities from Cape Cod to Western Massachusetts. Often the women working behind the doors of these establishments are living there as well

One day while inspecting a questionable massage parlor in Boston, Police Lt. Donna Gavin noticed something telling about the employees.

“They [the women] have a small suitcase with them and there's only one room, and they’re eating there, and you can just tell that somebody has been staying there," she said.

Gavin heads up the Boston Police Department’s Human Trafficking Unit. She said many of the women found in illicit massage parlors in Massachusetts have traveled a well-worn path from Korea and China through Flushing, Queens, eventually ending up in the Bay State. The illegal massage business can be the only option for some undocumented women from Asia. 

That’s what happened to one woman, who we’ll call Susan, the woman who answered the newspaper ad. She explained that she ended up in brothels disguised as massage parlors up and down the East Coast, including New England. She’s from southern China and arrived in the United States on a short-term business visa. 

“After I got to New York, I wanted to find a job, so people told me to read the newspaper and then you find a job,’’ she said. “At the time I thought it was just massages. And didn't think more about anything and the boss basically told me I needed to give my passport to them, so I will not run away with their money. The boss put me in a car. And drove me to somewhere.”

Susan was referred to the Asian Women’s Center, now known as Womankind, by anti-trafficking activists after being rescued from a massage parlor in Baltimore a few years ago.  

This clandestine industry is, ironically, often located in storefronts along or near main roads. The women stay for a few weeks and then disappear, said Gavin.

“They move around so much," Gavin added. "The majority of them come through New York and then they get on some sort of circuit.”

Another woman interviewed recently in Boston said she came to the United States to work in a restaurant but realized at the airport in New York that she’d been deceived by traffickers.

The woman, who requested anonymity because of her fear of the smugglers, said they took her passport and brought her to a bar where she was asked to fraternize with patrons. Later she was moved to a house where she was forced to have sex. She was moved to many places, often not knowing where she was, and sometimes asked to do massage.

She said she was too afraid to reach out to law enforcement, worried about her immigration status. She was later bused to states throughout New England before she was arrested. She blames herself for getting into the situation and not knowing how to get out. She said she's so ashamed about what happened and never has told her family. 

"I was so scared,'' she said through an interpreter. "I cried almost every day.''

This woman managed to escape, but many lured into this illicit trade stay there, said John Chin. He’s a professor of urban planning at Hunter College in New York and co-author of a recent study on Asian women massage workers. 

“A lot of the women we talked to say that they do the work by choice. But it's a little complicated, because the choice is really between being a nail salon worker, a restaurant worker or a massage parlor worker,” he said. “When you look at the wages and the conditions for nail salon workers and restaurant workers, massage parlor work actually starts to look fairly attractive.”

But Chin said the question of choice is also driven by another factor, violence. They are afraid to go to the police.

“They’re mostly undocumented immigrants, and they’re threatened with being reported to immigration officials by their boss or even by clients,” he said. “And this makes them vulnerable to being robbed, being raped.” 

Susan from China explained that once behind the closed doors of a massage parlor or in the back seat of the vans that transported them there, anything could happen. And it did.

“A lot of women who work in the massage parlor got robbed, raped,” she said, with tears in her eyes. “And there were other women like me who just came to this country, who didn't know what to do in those circumstances. Because the boss told me you cannot report to the police. If you report to the police they are going to put you in prison.”

Susan said at times, as her male customers lay comfortably on massage tables, she would hint that she was in trouble. But she said none of the men helped her. One such man interviewed by WGBH and NECIR said, “I didn’t want to get involved in human trafficking. I didn’t want to be a part of it. But I have no guarantee that I wasn’t part of that. In fact, I probably was.”

Phillip Martin is a senior reporter with WGBH News. Jenifer McKim is a reporter for the New England Center for Investigative Reporting, a nonprofit news partner of WGBH News.