For many of us ladies, getting our nails done is a regular bit of pampering. We stop off at the local nail salon, grab a magazine and relax while someone paints our nails. We pay our $25 and off we go.

We never, for one moment, consider the person doing our nails could be a slave.

For those who study human trafficking, nail salons have long been held as a hotspot for trafficking victims. But for the average client, the idea that the person hunched over their nails is literally a slave never crosses their mind. Last week’s New York Times followed women in four urban settings in the U.S., exploring the deplorable world they work in.

On a morning last May, Jing Ren, a 20-year-old who had recently arrived from China, stood among them for the first time, headed to a job at a salon in a Long Island strip mall. Her hair neat and glasses perpetually askew, she clutched her lunch and a packet of nail tools that manicurists must bring from job to job.

Tucked in her pocket was $100 in carefully folded bills for another expense: the fee the salon owner charges each new employee for her job. The deal was the same as it is for beginning manicurists in almost any salon in the New York area. She would work for no wages, subsisting on meager tips, until her boss decided she was skillful enough to merit a wage.

It would take nearly three months before her boss paid her. Thirty dollars a day.

Practices like this are widely known in the law munity, but it is rare that anything is done about it. Too many problems, too little staff. In large cities, it’s hard enough keeping up with cockroaches in restaurant kitchens; the human cockroaches who prey on these women are left to skitter about their business, relatively unchecked.

The juxtapositions in nail salon workers’ lives can be jarring. Many spend their days holding hands with women of unimaginable affluence, at salons on Madison Avenue and in Greenwich, Conn. Away from the manicure tables they crash in flophouses packed with bunk beds, or in fetid apartments shared by as many as a dozen strangers.

Ms. Ren worked at Bee Nails, a chandelier-spangled salon in Hicksville, N.Y., where leather pedicure chairs are equipped with iPads on articulated arms so patrons can scroll the screens without smudging their manicures. They rarely spoke more than a few words to Ms. Ren, who, like most manicurists, wore a fake name chosen by a supervisor on a tag pinned to her chest. She was “Sherry.” She worked in silence, sloughing off calluses from customers’ feet or clipping dead skin from around their fingernail beds.

At night she returned to sleep jammed in a one-bedroom apartment in Flushing with her cousin, her cousin’s father and three strangers. Beds crowded the living room, each cordoned off by shower curtains hung from the ceiling. When lights flicked on in the kitchen, cockroaches skittered across the countertops.

Don’t think that this only affects salons in New York and Boston; this practice is widespread. I recently stopped going to a salon when my daughter and I deduced the situation there was less than above-board for the young women working.

Many ladies looking for a bargain for their pampering don’t realize that a slave is paying the price. That $10 nail job is available because the person at your service is living a shadow life, a slave life.

If you suspect an issue of human trafficking at any business, you can always call your local law enforcement or the U.S. National Trafficking Resource Center at 1 (888) 373-7888.

Read “The Price of Nice Nails” at The New York Times.