Delhi, India (CNN) Manju Gaur climbs the staircase with a fierce but steady determination. The building is decrepit, some walls crumbling, others caked in a thin, greasy film.

Just ahead of her is a row of police officers. Some from her native Assam state; others from this working class neighborhood in West Delhi.

A few steps behind her are a handful of social workers and coordinators from Bachpan Bachao Andolan, a local charity that has rescued thousands of children from human trafficking.

But Gaur -- a victim of trafficking herself -- is here on a much more personal mission: Finding her little sister.

Manju Gaur left her home village in rural tea-producing India to find her sister in Delhi.

Gaur was born in a rural village in Assam. Her parents worked on a tea plantation, one of hundreds scattered throughout the northern state, which produces more black tea than anywhere in the world.

Officially, tea workers in her village are supposed to earn around $2 U.S. a day, plus the equivalent of around $2 U.S more as in-kind services provided by their employer, like free housing, medical care, and primary education. With no advanced education and no hope of a better life, Gaur desperately wanted a way to help her parents make ends meet. Read the Tea Industry's full response to CNN's questions

She still remembers the day the agent came knocking on her door. She was just 14.

"One morning, he came to our house and said that he would put us to good work," she says.

The agent said he could arrange for Gaur to work for wealthy homeowners in Delhi where domestic servants are often employed to do everything from cooking to cleaning to looking after young children.

Tea workers earn less than $2 a day but few know how much it product sells for across the world.

Gaur says the agent lived in her own village and was well-known. She thought she could trust him.

"I was easily convinced" she says. "We're poor and live in a broken house without a rooftop. I thought I could earn and help my parents, and my sisters, so that we could study."

She was wrong.

In Delhi, she was kept in a house with other girls from Assam -- just like her -- all waiting to be sold as domestic labor. That's when she says the violence started.

"If the girls didn't listen," she explains, "they often hit them."

In one case, Gaur says the man who appeared to be the ringleader gave one of the girls a drink that rendered her nearly unconscious, and then took her to an empty room upstairs.

"She said that they got her too drunk and she couldn't do anything to stop him. I saw with my own eyes the number of girls they abused," Gaur says.

JUST WATCHED Manju guar shows off her home village in the tea picking Assam aera. Replay More Videos ... MUST WATCH Manju guar shows off her home village in the tea picking Assam aera. 04:26

Throughout the ordeal, Gaur says she was too afraid to report anything to authorities. For one, she was new to the city and didn't know anybody. And more importantly, she didn't have anywhere else she could go.

Police in Assam say young girls from tea plantations are easy targets. They live in poverty, have very little education, and their parents are often saddled with debt.

Most are descendants of the original bonded laborers brought in from other parts of the country by British colonial rulers. They live in the same circumstances as they did more than a century ago, with the same impoverished lifestyles.

Police say young girls see placement agencies as a way to escape the cycle, lured by promises of good jobs and a steady income. Instead, they often find themselves sold as domestic labor or forced to work in the sex industry. Police say hundreds of girls in tea districts fall victim to traffickers every year. In the worst cases, fathers sell their own daughters as a way to escape poverty.

After she realized what was happening, Gaur says she pleaded with the men.

"I tried telling them that I wanted to go home," she says. "But [the agent] said that they had already spent a lot of money on me, and that my family had to repay all of it before they could let me go. And so, I had to stay."

Final processing at the tea plant before it is shipped to market where prices rise or fall drastically.

She wound up being sent to a middle-class home, working as a domestic servant. There was no abuse, she says, but there was also no money. Her employers told her they sent her monthly salary directly to the placement agency. She never saw a single rupee. She says she worked around the clock, but never entertained the thought of leaving.

"I was new there and didn't know anyone," she says. "Who could I have possibly escaped with?"

After a year, Gaur says she mustered up the courage to explain her situation to a friendly neighbor, who gave her enough money for a train ticket back home. She didn't tell the homeowners she was going. She just took her things and left.

Gaur says life in her village in Assam is still better than working for the trafficker, but now she has another problem. Her sister, Aarti, has been lured away by traffickers. The last time Gaur spoke with her on the phone, she was in tears.

For help, Manju Gaur has turned to Bachao Bachpan Andolan, or the BBA. Its founder, Kailash Satyarthi, is a Nobel Peace Prize winner for his work in combating child labor and trafficking.

The BBA has arranged to bring Gaur to Delhi, where they've traced the trafficker's location to a non-descript apartment complex.

As police barge through the doors, calling out the trafficker by name, they have no idea what they'll find.

Gaur is led by police, room by room, asking if she recognizes anyone. She doesn't, and when they turn the corner to the next room, they find something that unfortunately is commonplace in raids like this.

India's tea producing heart is beautiful but poverty can drive tea workers into the arms of traffickers.

Three young girls, all huddled in a corner. They look frightened and shell-shocked. They tell police they're all from Assam, and that they were lured to Delhi by a man who said he worked for a placement agency. They say they were told he received 15,000 rupees -- just over $200 -- for each girl he brought in. But they haven't seen any money.

"He told us he gave my mummy the money," the youngest girl says.

Upstairs, police finally nab the trafficker, a man with a slight pot belly. When they bring him down, he appears unremorseful, insisting the girls came to Delhi of their own free will

Outside the police station, CNN Freedom Project confronts the trafficker with accusations that he was exploiting the girls

"They were not bought" he says. "We take a 35,000 (rupees) service charge for an 11-month agreement. Those who bring them from the village get 25,000 for an 11-month base.

"Some girls' husbands bring them. Some (girls') fathers bring them. They also get a commission.

Later, inside the police station, they prepare the formal charges, including bonded labor and cruelty to a child. While the suspect awaits, he cuts a deal with the police. He agrees to tell them where Manju's sister, Aarti, is working.

Two hours later, a smiling Aarti appears, accompanied by police. Gaur runs into her arms, with the kind of hug that only a loving sister can give.

Vijay Gaur, Manju and Aarti's father, says the offers from human traffickers can seem tempting.

She knows there's a long road ahead. Aarti will be questioned by police and social workers, sent off to a nearby clinic for a mandatory health inspection, then spend weeks rehabilitating at one of the BBA's shelters for rescued children.

But still, for Manju, it's still a victory. Aarti is free. They're together again. For now, that's all that matters.