Less than a mile from quaint downtown Powell, the women were living in a storefront massage parlor. Not by choice, police say, but by coercion. They bathed there, cooked there and slept on massage tables that by day were used for men who expected more than a shoulder rub. As the January bust that shuttered Amsun Spa and others showed, Asian massage parlors are more than tasteless punch lines. They are real, they are here, and they are both home and prison to the women forced to work in them.

Two wooden, hand-painted signs common in towns stuck with the "quaint" label, are posted just outside Powell Police Chief Gary Vest's offices. One points to the O'Shaughnessy Dam and High Street, the other to Columbus and Delaware-cities 17 and 11 miles away, respectively. But your destination on this day is much closer: one-third of a mile down the road.

From the police station, you turn right onto East Olentangy Street and pass many of Powell's vibrant storefronts, including the ultra-hip Kraft House No. 5 restaurant, Prohibition Gastro Lounge and Jeni's Splendid Ice Creams, 'til you're just beyond the downtown square.

As strip malls go, the one you seek is nondescript, all brick exterior and maroon awnings, but there's safety in this disguise, a sense of legitimacy that comes with this out-in-the-open location.

You turn into the driveway to the Powell Center strip mall, past the marquee advertising two churches, a dentist's office and a daycare. The first business you'll see is a travel boutique promising "One Trip to Paradise." The sentiment might resonate with this quest, but you're not seeking those services.

Today, you're a monger, and you're interested in something far more unusual: Asian massage parlors.

You heard about this particular place from fellow mongers in an Internet chat room dedicated to this interest. You've read their reviews, you've done the research. You're ready for your own happy ending.

But this journey couldn't be duplicated because, a matter of months later, it was all over. The parlor closed, the target moved. Your future quests shifted to any of the dozens of other illegitimate massage parlors in Central Ohio, each one placed in affluent suburbs around Columbus.

You escaped unscathed, because you were smart enough to pay cash, use a fake name, park far from the strip mall and walk to your location-all tips and tricks you learned from friends on online review websites just for Asian massage parlors.

Some of your fellow mongers weren't so lucky. They got caught up in what was the largest human trafficking bust in Central Ohio in a decade.

On Jan. 14, police raided four locations-three Asian massage parlors and one apartment-in Powell, Worthington and Columbus. Officials believe all the locations-two under the name Amsun Massage and one called Rainbow Massage-are connected to a human trafficking ring that stretches from California to New York City to China. The same day, federal agents raided three other massage parlors in Central Ohio, also believed to be connected, but details of those raids have not been made public. Federal agents are investigating the spas' possible role in trafficking people and money between states and internationally.

At least three people were arrested in connection to the local case. They've pleaded not guilty to charges, including promoting prostitution and money laundering. Two of those arrested, sisters Estella Xu, 54, of Pomona, California, and Qing Xu, 57, of Columbus, were free on bail while awaiting trial. Qing Xu's husband, Xiao Shuang Chao, 56, of Columbus, remained in the Delaware County jail.

The targeted massage parlor sites have been closed, but others could be waiting to replace them. The demand from mongers is simply too strong. Illegitimate massage parlor operators know this, and they're eager to cash in. Supply, in other words, isn't lacking.

According to a 2014 study by the liberal-leaning think tank Urban Institute on the underground commercial sex industry in eight U.S. cities, the total industry-inclusive of Asian massage parlors, brothels, street-level prostitution and other sources-fetched between $39.9 and $290 million in 2007, depending on the city.

This demand led to the opening of nearly 600 new illicit massage parlors in the U.S. from 2011 to 2013, pushing the total number to almost 4,800, according to the Urban Institute. A lot of that growth occurred in the South and Midwest, two markets that were previously largely untapped. But it's hard to know exactly how many are operating in Ohio, and that's by design.

"[The massage parlors] present themselves as legitimate businesses, so it's not like you often see something that alarms you or that would make an adjacent business call in," says one Columbus vice detective, who asked we not use his name because he works undercover. "People going to these places know why they're going there, but they're not going to call the police."

Police investigations are based in part on online reviews of massage parlors in Central Ohio; mongers on just one of these massage parlor-specific review sites have reviewed 27 parlors in Central Ohio in the last several years.

Exact figures on how many women are trafficked into the sex trade in Ohio, and specifically into Asian massage parlors, aren't known. That's partly because the Ohio Attorney General's Human Trafficking Commission lumps all human trafficking victims together, whether they were involved in the sex trade (Asian massage parlors, street prostitution) or the labor trade (nail salons). The nature of how Asian massage parlors operate also makes it difficult to arrive at a reliable estimate, says Celia Williamson, a professor of social work at the University of Toledo who specializes in human trafficking. Williamson also chairs the commission's research and analysis committee, making her one of the state's lead resources on documenting this issue.

"We can't tell you specifically how many people are forced into massage work or domestic servitude every year, because we know the women that work in those massage parlors are typically moved around frequently from massage parlor to massage parlor and city to city," Williamson says.

The commission estimates 783 foreign women are trafficked in Ohio every year, whether for an Asian massage parlor, a nail salon or other work. That estimate is considered low, Williamson says.

The commission came up with its figures for Ohio through forecasting models that estimate the size of the foreign human trafficking trade in the United States at large. Those models consider factors like the number of immigrants in a city. "When you have a hidden, underground group of people, you can't definitively say," Williamson says. "It's not the best way [to estimate the number of victims], but it's the way you have to begin."

Williamson says Asian massage parlors represent one of the most difficult aspects of human trafficking to research and understand because there are so many barriers to the women.

The only people who have access to the victims are their customers and their captors, and the women are moved from city to city frequently; captors don't want the women to learn too much about their location or form relationships with repeat customers who could help them escape. The women are also moved, Williamson says, to keep fresh faces in front of customers and make sure the women remain ignorant of U.S. cultural norms.

"[The women often] don't even know we'd consider them victims of a crime," Williamson says.

The victims and their captors are also often from the same ethnic group or might know each other's families, so the threat of violence against relatives at home also looms. The victim's family can be blacklisted by their captors, thus ruining any chance other family members might have of getting assistance to flee their home country.

Most of the 18 women rescued from the Amsun and Rainbow Massage locations are in their 30s and 40s and speak little or no English; most of them came from the same province in China. Since being rescued, they've been moved to various temporary and permanent safe houses in Central Ohio and elsewhere.

While they were at the massage parlors, the women were effectively prisoners, never leaving the spas for any reason. They slept on massage tables at night, bathed in a standup shower stall, made meals with rice cookers, microwaves and slow cookers and kept a fridge stocked with pantry staples like potatoes, eggs and meat.

They were expected to provide sexual services for customers, in part to pay off debts for food, shelter and the cost of the voyage from China to the U.S. Though investigators believe most of the rescued women were in the country before being recruited to work in massage parlors through domestic Chinese-language websites and newspapers, it's not uncommon for victims to accrue massive amounts of debt just to get to the U.S.

According to the Urban Institute study, human trafficking victims can accumulate up to $50,000 in debt for transportation from China to the U.S., often through indirect routes with layovers in places like Guatemala. Sometimes women believe they're coming to the U.S. to enroll in school, become a nanny or join a legitimate massage therapy business. (Some of them, once in the U.S., become lawfully licensed massage therapists; others obtain their forged credentials through other means.) These circumstances make them ideal prey for massage parlor operators.

"[The people running the massage parlors] know there are people who have come here from China who are either trying to claim asylum or trying to live here because there's better opportunity, and they know they can target those people because they're vulnerable," the Columbus detective says. "They're easy bait and a lot easier to manipulate and get into this situation."

The level of sophistication and deceit used by massage parlor operators sometimes shocks even veteran cops. This organized crime network is not quite like the Mafia or others depicted in movies. Think more mom and pop-small, independent, family businesses with a loosely connected network of likeminded affiliates. Sometimes there's a hierarchy, with one person running the entire network, but most often the syndicates work in tandem, helping meet each other's needs.

"For one organized crime group to be able to facilitate this by themselves is an enormous undertaking, so they work in smaller groups," the detective says. "That's where they differ from narcotics. They work together because there's enough money to be had for everyone. … They don't have to worry about rival people getting in their territory. There's so much demand that why fight?"

Some arms of massage parlor networks specialize in the transportation of the women, others in forging documents. Some might specialize in housing; others have ties to government contacts paid to look the other way. Some teach people in other networks how to hide money; many savvy syndicates transfer money to their home country or hide it in other business assets, whether around the corner or in another state.

This level of subterfuge not only makes it harder for law enforcement to track the network, but also to estimate just how large it is and how deep its pockets are. The assembly-line setup helps massage parlors stay mobile and avoid detection.

A new massage parlor can set up in a strip mall, advertise its business online and get customers in months, if not weeks. Just as quickly, the parlors, tipped off to police suspicions, can likewise tear down and move in a matter of hours.

"They will change in less than a day; they will change in the two hours it takes to load up and drive your crew there to execute a search warrant," says one Columbus police sergeant, who also works undercover with the vice unit. "All they have to do is pick those people up, throw them in a vehicle and haul them down the road for six, seven, eight hours and start over."

Upright Management property manager Ralph "Bud" McNichols first took a call from the U-Spa Massage Therapy, a company based in Montebello, California, in late summer 2014. The company operates several massage parlors under various names, and already had at least one in Central Ohio. They were interested in expanding their reach in the area, and wanted to open an Amsun Spa in Powell.

Most of the U-Spa representatives McNichols encountered didn't speak English, so it took a couple weeks to find a translator to help with contract negotiations. It wasn't until Sept. 12, 2014, that the two sides got together in person to sign a lease for the Powell Center strip mall space. By that time, McNichols had already pored through the company's brochures and its website to see whether U-Spa would be a good fit for his Powell Center location.

"As I went through the series of questions on their business and what they were allowed to do and the extent of their business plan, it looked totally legitimate," McNichols says.

At the time, U-Spa already had a Hilliard location and another spot in California. The spa's brochures and website touted reflexology treatments, trigger-point therapy, hot stone treatments and more. The business billed itself online as "Your Mini Vacation Destination" and described its mission in similar terms: "Our mission is to provide the most excellent service possible to make your visit with us a most recuperative, restorative, relaxing and rejuvenating therapy experience. We care about your wellness."

This approach appealed to McNichols.

"My interest was the actual health therapy that people who are older often need," he says. "And since we had the types of businesses we had in Powell Center, I wanted to make sure it was leaning more toward the medical field or educational field.

"When I signed [the property-lease contract], my understanding was they were all licensed health therapists and not necessarily massage therapists."

Before September was over, Amsun Massage Spa was seeing clients.

When a new business opens in Powell, Police Chief Gary Vest likes to send an officer as a welcoming party. In case a break-in or a fire happens at the business overnight, Vest likes to know who to reach out to.

Police didn't make this routine visit to Amsun until Oct. 22, because local officers didn't know the business existed. The massage parlor didn't file the proper paperwork that eventually trickles down to authorities, alerting them of a new enterprise, Vest says.

"They didn't get a building inspection, occupancy permit, the normal things you do [when you open a new business]," Vest says. "So when an officer went, that's the first question I asked: 'Why didn't we know this was a new business?' "

Soon after, cause for concern flared. A few days after their initial visit, Powell police received an anonymous letter that alerted authorities to the business' true nature.

"These people have done nothing to me, but have sincerely hurt one of the girls who left when she found that they lied to her," the tipster wrote. "They told her that they do not do bad things their [sic] and after spending much money and time to get their [sic] found that they were nothing but whorehouses."

Vest turned the letter over to the human trafficking commission, which includes law enforcement officers from local, county, state and federal agencies as well as representatives of government, schools, and religious, academic and social-welfare organizations. Powell police immediately started electronic and physical surveillance of the location.

By November, word was starting to spread in town. Employees of neighboring businesses called McNichols after, Vest says, "A couple guys had walked out on a Saturday morning and commented about their happy ending, and it was heard by somebody nearby."

A monger who uses the online handle "ohiosensi" posted his two-star review of the Powell Amsun on Oct. 7, mere weeks after the spa opened. His review covers the cost of services and the ages of the women working at the parlor, as well as their hair and eye color, hair length and breast size. He checks off the various services one could expect to receive there. Ohiosensi writes he didn't get the name of the girl who gave him his "nice" and "light" massage, then went into more graphic detail about where his roaming hands were allowed (or not) and how the massage ended. The entire review is written as if he's talking about the latest Short North steakhouse.

Before it was raided by authorities in January, the Powell Amsun location was reviewed three other times, twice by one monger who goes by a particularly vulgar name. He's one of the site's most prolific Columbus reviewers.

This reviewer often plays the role of message-board sage, admonishing users for not posting enough and encouraging others to keep visiting the parlors so the businesses will learn their faces and the mongers will earn their trust. His Nov. 12, 2014, four-star review of the Powell Amsun notes that it's "very new and clean," but laments its out-of-the-way location (other mongers online note this as a positive, because they're less likely to be recognized by neighbors or acquaintances). He then matter-of-factly describes his undressing and subsequent massage. "She gave a regular massage with almost no sign of things to come," he writes. "[A]fter the flip pretty much the same until the end!"

In a three-star review posted in December after another visit, he expresses enthusiasm about the looks of his masseuse at the Powell spot ("She is very attractive"), but is bummed to receive only a massage. For this slight, he didn't leave a tip. He says in the review he later regretted this, but he's quick to add he hates being led to believe a certain service will be provided, only to leave disappointed.

A third review of the Powell Amsun location, this one from user "ukemi2000," suggests leaving the "tip in plain sight before the massage began," so the women know what's expected.

Sometimes the mongers are satisfied with a simple massage, but more often they want both legit and illicit services, even if the women aren't enthusiastic about the arrangement. For instance, the Worthington Amsun location was reviewed five times, but many of the message board users criticized the spot for its customer service. In his December review, "ukemi2000" wrote of his four-star experience, "Fairly mechanical, but it got the job done."

"A lot of it is the build-up," the Columbus vice detective says. "That's why a lot of these massage parlors have the girls dress in provocative clothing, and you'll see on the message boards a lot of the guys will talk about touching the girls."

The detective says he's learned the hunt can become a game, an obsession for many men. They love exchanging intelligence to maximize each visit and bragging to their online friends about each "successful" visit. "And these massage parlor owners know this," the detective says. "They pick locations in strategic areas. They pick suburban areas because they know there are males with disposable income. Hilliard, Worthington, Powell-there's no mistake they put their business there."

The reviews on these sites can even play a significant role in determining where a new spa is located.

"You can see how some of these massage parlors are [physically] close to each other and a lot of that boils down to the reviews," the detective says. "If one place is getting a lot of good reviews then that's where the guys will be drawn to."

The websites go well beyond reviews, too. They often include forums in which users can seek advice, ask questions and discuss the ethics of their pastime. ("Is it really cheating?") There are glossariesthat decipher abbreviations and slang used on the sites ("DDE: Doesn't do extras."), and webcams. It truly is a community in some sense, the detective says.

The massage parlor review sites are the latest wrinkle in law enforcement's ongoing fight against human trafficking.

Their presence is both a boon and hindrance to investigators. They make it easier for cops to track the massage parlors, but once there, they are often met with dead ends.

"There's a lot of different ways you can disguise where something's coming from," the detective says. "You can get a fake email address, fake name, you can post from a location that's a public place so the IP address comes back to a coffee shop. Most people think, 'Oh, you should easily be able to find where [a massage parlor] is, but some of [them] are very sophisticated and they mask things most people would think are readily available to us."

The investigations that led to the January raids moved with unusual speed. "There were some things shown to us, told to us, through letters and phone calls that made us go, 'OK, we now have some good, specific information and we should probably focus our resources on these [massage parlors],'" the detective says.

Since the raids in January, authorities have been inundated with tips. Some calls came from about 20 to 30 male clients of Amsun, each one reaching out to law enforcement in the hopes their cooperation might win them leniency. Other calls came from residents concerned about massage parlors in their neighborhoods.

"In the last week alone, probably three to four more locations have been brought to our attention that people want help with or at least a fresh set of eyes to look at if it's a legitimate business," the sergeant said in a February interview. "We will get to those, but I don't know when. It's very labor intensive, and we are a small unit."

While investigations continue, other agencies and organizations are helping the women who were rescued. This approach is relatively new to Ohio.

In 2011, state attorney general Mike DeWine launched the Human Trafficking Commission after a report showed the scope of the problem in Ohio. A similar commission, created by previous attorney general Richard Cordray, served mostly to release reports and recommendations for how to combat these crimes. Among the practices DeWine's commission adopted from cities in other states was to focus on helping victims.

The following year, the Ohio House of Representatives passed House Bill 262, commonly called the Safe Harbor Law. In addition to increasing the penalties for traffickers, the bill also improved care for adult human trafficking victims by, among other concessions, allowing them to have their records expunged.

That was a sea change that Michelle Hannan, director of professional and community services at the Salvation Army, says has paid off in Columbus. Instead of treating the rescued women as criminals, government has started responding to them as victims. Agencies like the Salvation Army have joined the Human Trafficking Commission to provide rescued women shelter, food, clothing and any other services they might need.

In part, it's the humane thing to do, the sergeant says.

"When we remove them from this environment they have nothing but the clothes on their back," he says. They do not have income, they do not have food being brought to them. So we need to provide that."

The Salvation Army provides, among other services, a survivor hotline, emergency short-term housing, health care, legal assistance and translator services, either through outside organizations or their own employees, including a victim advocate who often attends raids with cops so victims immediately have someone to talk to. With time and care, victims start to trust law enforcement, and this leads to greater cooperation with investigations.

"Sometimes in the trafficking dynamic, a fear of law enforcement is instilled, so even though we're saying you can really trust this team, they're like, 'I'm not meeting with law enforcement, no way.' The sooner the victim advocate gets to start to talk to them, the better for the longer-term engagement," Hannan says.

In the lead-up to the January raids, the Salvation Army arranged to provide many of the women's basic needs, including safe housing, culturally familiar meals, attorneys and medical care. They arranged for a translator fluent in Mandarin to accompany police on the massage parlor raids so the message was clear from the start: "We're here to help you."

The results have been positive, Hannan says. One of the victims was so overcome with gratitude she made dumplings for police officers, and many others have expressed their appreciation to the Salvation Army team.

But, Hannan says, it's all for naught if demand can't be curbed. Clients must get the message, too. "We have to keep prosecuting and investigating and helping victims and raising awareness, but we can do that for eternity if we don't stop it more on the front end-that's the only way to stem the tide."

Columbus officials believed they had eradicated Asian massage parlors in Central Ohio after a series of large busts in 2005. Four women were arrested that summer, charged with running two North Side brothels masquerading as massage parlors. Officers found $743,000 in cash and records from a bank account containing about $1 million. Bond for one of the women charged in the case was set at $1 billion.

Three weeks later, Franklin County deputies raided a massage parlor in Blendon Township and arrested two women on prostitution charges.

"We put an absolute hurting on them," the sergeant says. "When we hit them, we hit them with nine or 11 search warrants simultaneously, and basically eradicated the problem and made it like, 'Hey, Columbus is on top of this. We don't want anything to do with it.' "

In hindsight, the detective says, these busts displaced massage parlors in Columbus only temporarily. That pattern often plays out across the country, too.

An echo of this can be found in comments made to the Urban Institute by Washington, D.C., officials. Because they found Asian massage parlor cases so difficult to prosecute, D.C. resorted to shutting down the massage parlors by citing public health or public nuisance concerns, instead of trying to launch full-fledged investigations into crime networks. Officials boasted in the report about how well this solution has worked for them, but they also acknowledged it's merely moving the massage parlors elsewhere.

This game of Whac-A-Mole ensues across the country, with each town's efforts to shutter the businesses creating a problem for another community. It's why the vice detective believes the problem will never be permanently solved in Columbus. The demand will always be there.

Indeed, prostitution, it's been said, is the world's oldest profession. In the United States, the practice was largely legal until the early 20th century, when the Mann Act was passed. This 1910 law made it a felony to transport, either between states or internationally, any woman or girl for the purpose ofprostitutionordebauchery, or for any other immoral purpose." Five years later, most U.S. states passed their own laws banning prostitution.

As cultural norms changed through the years, so too did the country's laws on prostitution and human trafficking. The rise of AIDS in the 1980s increased concern about public health problems created by prostitution, and in 2000, Congress extended protection to undocumented immigrants with the passage of the Trafficking Victims Protection Act.

One local approach meant to curtail demand, at least from a domestic prostitution perspective, is found in a Columbus program dubbed "johns school," which was launched in 2007 with the aim of rehabilitating men who've been caught in prostitution stings. The school features former prostitutes as guest lecturers, class discussions on the costs of human trafficking, and visual aids that include color slides of sexually transmitted diseases.

The school, however, has never enrolled a student caught in an Asian massage parlor bust, and it's not entirely clear how effective the program is, says Mike Allbritain, the assistant city attorney who runs the school.

"Unfortunately we've had a couple repeat offenders that came through in 2014," Allbritain says. "I don't know how to view that. I was obviously upset that it happened, but it's a sign that more stings are taking place, more actions are taken to get arrests. But maybe there are guys that go through the program and didn't get caught again.

"There are a lot of guys who come up to me and say this has really, completely changed their view on things. They wish they had known this stuff beforehand."

Williamson, the social work professor and member of the Human Trafficking Commission, says research has shown similar stubborn mindsets prevalent in men who frequent massage parlors. These men, she says, are unable to view the women as victims.

"The women put on this massage for the men, so the men have no idea that this is a trafficking victim," Williamson says. "So the men get the impression that, 'Oh, these women are enjoying this.' The men think they're engaged in consensual adult commercial sex and the law is really bogus, like the law should allow two willing adults to engage in sex for money.

"The man that is ignorant to what is actually happening is the one we're trying to reach, that perhaps you should think twice before you get the idea that this is somebody doing this of their free will. But there's a percentage of men who will hear that message, understand that message and won't care."

This is borne out frequently on the message boards. Many mongers comment on the women's robotic actions or how hesitant they seem to be to go through with their client's expectations.

As the monger with the vulgar handle put it in a July 2014 comment online, "Some of these are hard working girls doing what they are told to do and if you spend a little time and money you can get what you want in a safe and clean environment and I have plenty of both and love the challenge."

It's this mindset that most scares the vice detective. No matter how successful local police are in targeting and shutting down these massage parlors, the detective says, the issue will never go away. It's cyclical. The demand will always be there. It always has been.

"This is an issue we've had for hundreds of years [in the United States]," the detective says. "You can go back to the gold rush, you can go back to any kind of large project, whether it was the Hoover Dam or the Suez Canal, and there's men away from home who have down time and have trafficked women.

"In order to attack demand, you're going to have to attack a culture and society in terms of how women are viewed and how prostitution is viewed. When we start to do that, that's when it'll start to change."