By Vivian Kuo, CNN

Savannah, Georgia, (CNN) - An agent presses against a light blue wall and it gives way. Behind it is a makeshift room made of foam insulation and a cheap plywood frame.

The woman inside is believed to be a victim of a human trafficking ring that law enforcement agents busted during a four-state coordinated raid Wednesday.

She is on a small bed with a thin mattress on springs. A large free-standing mirror sits to the side, and clothes are strewn across the floor.

Upon surveying the scene inside the Savannah, Georgia, townhouse, Brock Nicholson, the Immigration and Customs Enforcement special agent in charge, said he's never witnessed a situation like this.

"[This] is basically where they had the victim, where she serviced commercial sex acts, her hellish life is. She lived - all of her possessions, the tools of the commercial sex trade - all in this one little 10 by 12 box," he says.

Shortly before discovering the woman - one of 11 sex slaves rescued that day - about 120 agents from more than 10 law enforcement agencies joined forces in a highly coordinated raid covering 16 locations in Georgia, Florida and North and South Carolina.

It's no easy task when you consider that each location had to be hit at precisely the same time. Arrive at one house a few seconds early, and the operation is blown.

All it takes is one phone call or text message among the alleged conspirators and the police could lose their suspects - and the chance to dismantle a sex-trafficking ring authorities believe is responsible for the imprisonment of at least a dozen women.

The effort begins at 5 a.m. The moon is still up, and more than a dozen cars and trucks have converged on what would ordinarily be a deserted mall parking lot in Savannah.

A horde of law enforcement officers, all wearing dark shirts and pants, many with walkie-talkies hanging on their belts and holstered guns strapped to their thighs, discuss the day's mission - the culmination of more than six months of police work.

The eighth floor of a downtown Savannah office is similarly filling with activity. The heart is a conference room-turned-command center. Large posterboards display maps and diagrams under the bold heading: Operation Dark Night.

Back at the staging area in the mall parking lot, the agents begin assembling around 5:30 a.m. There's a sense of nervous anticipation.

"We're talking about the goals, who's going to accomplish them, who's going to do what," explains Nicholson, who is based out of ICE's Atlanta office. "You can't plan for everything, but certainly, if you think it out a little bit, you're better prepared."

The pre-operation briefing is quick. In minutes, the parking lot empties as the officers and agents climb into their vehicles.

Their destination is just a few blocks away, and agents believe that inside the targeted townhouse is the alleged trafficking operation's ringleader, Joaquin Mendez-Hernandez, who goes by the nickname, "El Flaco," Spanish for "the skinny guy."

Nicholson parses no words in expressing what he thinks of El Flaco: "When it comes down to going in, they'll be focused. Especially in a case like this where they're hoping to rescue someone, and hoping to put away a pretty heinous dude."

At 5:50am, the command center comes alive as various teams call in. Ryan Spradlin, a deputy special agent in charge with the Atlanta bureau of ICE's Homeland Security Investigations, coordinates efforts.

"This is where all the operation info is being vetted and called in," he says. "Everyone's locked and loaded and ready to execute those arrest warrants."

Meanwhile, a cavalcade of vehicles files into an apartment complex, the agents still inside, quietly coiled, weapons at the ready.

When the clock hits 6, the officers storm the townhouse, pounding on the door and announcing themselves. Moments later they gain entry after smashing through the red front door with a battering ram.

Inside, they find El Flaco and an unidentified man. Two HSI agents bring out the alleged ringleader first. He's sporting a white T-shirt, jeans and loosely tied sneakers,

His hair is closely cropped. His head is down. There's a sullen expression on his face. Mendez-Hernandez is charged with six counts relating to sex trafficking, including travel in interstate commerce for the purposes of prostitution. In a court appearance, he did not give a plea.

"It's not often you get to see a monster in person," Nicholson says.

The woman from the secret room comes out next, accompanied by two female HSI agents.

Her face is streaked with tears. She is taken to a nearby hotel to be questioned as El Flaco is taken to jail.

The unidentified man emerges last. He stares straight ahead as he, too, is taken into custody. His relationship to the trafficking ring is unknown. Police consider him an added bonus to an already productive day that's just showing the first hints of dawn.

Back at the command center a flurry of calls come in, and by noon, police report that another dozen males have been taken into custody, and several more women have been freed.

At another location in nearby Port Wentworth, Georgia, several school buses are weaving through a tidy subdivision, picking up children heading to elementary school.

Among the well-tended houses, one home sticks out. Debris litters the yard, and a rusty '80s-era pickup sits half in the driveway and half in a yard full of brown grass. A beer bottle sits atop a laundry machine on the front porch.

Cops stand outside the house, several wearing full face masks to protect their identities. They're here for more key players in the sex-trafficking ring: the johns.

"They are the demand. They are the reason that these services are being provided. If there were no johns, there wouldn't be this problem," U.S. Attorney Ed Tarver says. "We want to hold all of the individuals responsible for this taking place. We want to prosecute everyone who made this happen."

As HSI officers deposit boxes of confiscated evidence into unmarked cars, three men come out of the house, two illegal immigrants and an American citizen.

In a neighborhood minutes away, two trailers are also raided. At one, there are Negra Modelo beer cans on the step, and a fast-food bag sits on the porch's railing.

Women were brought to these trailers, and johns lined up for their services, agents say. A 21-page indictment details how women would sometimes service 30 or more men a day. The price? Officials say johns paid thirty dollars a visit.

For many of these women, it's a continuation of a long pattern, explains the woman charged with coaxing them out of a shell of distrust and abuse.

"They may have been arrested, sexually assaulted as a child, may have been in a home where domestic violence exists. That's a pretty common denominator with a lot of the victims that we encounter," said Alia El-Sawi, a Department of Homeland Security victim assistance specialist.

El-Sawi has already met with several women who were rescued from their captors, and there's much work to do, she says.

"You have to realize a lot of these women are talking to you as a complete stranger, and we're expecting them to tell us their whole history of their victimization, just upon first meeting us. So, naturally, there's some hesitation because we are complete strangers, because we are affiliated with law enforcement, but our job is to try to build that rapport, try to put them at ease, and hopefully assist them," she said.

El-Sawi continued, "A lot of these women, and sometimes children, are traumatized by what the traffickers have done to them. They've been deceived; they've been brought here under false pretenses."

Their emotions, El-Sawi says, run the gamut.

"We have some that are very closed off emotionally and hardly want to speak. We have others who are wanting to vent, to get it all out. We have some that are very angry at what's happened to them, and they take that opportunity to let it all out, and in a way, are speaking out for the first time."

None of the women speaks publicly, but officials say they hope they will cooperate, possibly by revealing the locations of more enslaved women or by identifying more perpetrators.

For victims of trafficking in the United States illegally, there's often a fear of deportation – something their captors often use to brainwash them. ICE Director John Morton said this shouldn't be a concern, though.

"The law expressly allows for these women to be given temporary immigration status so that there isn't any threat of deportation. They can come forward, help us with our investigation and prosecution and work with us to get them back on firm footing. Ultimately, the law allows for them to stay permanently in such circumstances," he said.

The road to recovering from the horrific treatment many of these women have suffered is a long one, but El-Sawi says success stories abound.

"On a personal level, obviously it makes me feel better to know that someone that's been victimized for a number of days, months, years is finally able to make their own choices for once. For a long time, many of these women had no choices. The traffickers had complete control over them," El-Sawi says. "Knowing that they're going to be stabilized, some victims keep in touch, call and say, 'Hey, I got my GED, I'm in a healthy relationship, I've opened my own business.' They've thrived."

Agents considered Wednesday a good day. Ten out of 12 individuals named in a federal criminal indictment were arrested. Another three were arrested based on information gleaned over the course of the day, and at least 40 other men were taken into custody.

"I'm very excited about this because when we received the allegations regarding this behavior, we thought it was a smaller scale. After we looked into it, we discovered it was a much larger scale than any of us could have imagined," Tarver said. "And to have the opportunity to shut down an operation of this size gives us a tremendous feeling of accomplishment."