Editor's note: This article is part of The Fighters, a series of reports from a full-length film that premieres on CNN International TV on May 17 and 18 at 1900 HKT; 2200 CET; 2200 ET. The documentary is a result of two years of undercover work and filming in the Philippines.
Manila, Philippines (CNN) -- Bolly is working the streets, watching clubbers spill from one bar to the next when he spots his next mark -- two westerners in one of Manila's most notorious areas.
It's a little after 10pm when Bolly sees me and my cameraman -- though he doesn't have a camera visible with us on this night -- rolling out of a sports bar known for its bounty of women offering 'companionship' in Edsa, Manila's unofficial red light district. He strides over quickly, waving a little white flier in our faces.
The street is teeming with people after an evening rain. Pedestrians dodge neon-bathed puddles while darting behind and between passing cars.
On the sidewalk, several homeless families have bedded down on cardboard for the night. On the block ahead, we see teams of girls in tight-fitting cocktail dresses and school girl uniforms standing in front of karaoke bars, calling out to western businessmen to come inside and join them for a little fun.
"Hello friends. Where are you going?" Bolly says. "I know where there lots of girls. Cheap drinks. This way," he says, thrusting the pamphlet into our hands. Bolly is a recruiter for a number of nightclubs in the area.
"We are looking for young, pretty girls" my cameraman asks, playing the part. "Where can we find them?"
Bolly grins broadly. "OK. I take you."
We make small talk as Bolly happily walks us the several blocks to the first bar.
My photographer and I don't tell our new friend that we're actually working at the moment; on the lookout for evidence of forced prostitution or children being sold for sex. It's part of the two year-long investigation CNN embarked on as part of its Freedom Project, an initiative to help the battle against modern-day slavery.
It's estimated 800,000 people are involved in prostitution in the Philippines. The government and NGO estimates on the number of women trafficked range from 300,000 to 400,000 and the number of children trafficked range from 60,000 to 100,000.
We follow Bolly down the street, until we come upon a little door guarded by a large bouncer. He opens the door and our eyes struggle to accept the flood of pink fluorescent light bathing the room. Katy Perry's "Teenage Dream" blares from unseen speakers.
Along the wall a dozen girls seated in a row stare at the newcomers. A few wave hello, most look bored. They're not drinking. Not really even talking. Just sitting and waiting to be selected.
A few red plastic tables are scattered around the room, each decorated by a single man sitting and drinking.
One man has a girl he's chosen sitting beside him. She's kissing the lobe of his ear. There are no empty tables left, so the manager puts us on the side of the L-side couch, opposite the girls. It feels a little like it's an adolescent school dance, with everyone waiting for someone else to make the first move.
I struggle for a place to look away from the gaze of the girls and cast my eyes to the ground. A cockroach skitters around the legs of the tables and chairs and patrons' feet. The manager is behind the bar, getting us beers. She sees me looking at the cockroach and laughs from across the room. "Our pet," she says.
The girls giggle, somewhat embarrassed. I force a smile, but another patron, who hadn't heard the quip gets up from his chair and smashed his shoe down on the husky insect.
The girls groan and the manager pretends to cry. This is too weird. Time to go. My photographer and I race through our San Miguel Lights and leave.
Bolly is there outside the door. He leads us through a labyrinth of roads and alleys. Fifteen minutes later, near the Manila port, we arrive at a strip club.
We're seated near the front of the stage, where two girls sway in a bored dance. This time instead of the girls sitting in a line, the manager brings them to us.
More than a dozen girls in skimpy cocktail dresses line up in front of us. The manager shines a flashlight across each of their faces. He tells us to select one.
"No, that's okay. I don't want one," my photographer says.
In the back, smaller than the others, I see a young girl, hiding behind the others. I can't tell if she's frightened or uninterested. "Her."
The other girls part way. She hesitantly makes her way to sit beside me. She orders an ice tea. When the bill arrives, we'll find out it cost us $22. How old are you? I ask "18," she says.
"Really? You look younger." She doesn't budge. "18,"
"Do you like working here?" She looks forlornly at the stage. "Yes."
How long have you been working? "Three months."
Despite our best efforts, she has no interest in giving up information to two white strangers.
We decide to leave and end up getting into an argument with the manager. The bill for two beers and an iced tea comes to $83 dollars.
But carrying undercover camera equipment, and because of the size and number of security guards, we only offer a half-hearted protest.
We would go to several other bars and speak to a number of women working in the sex industry.
Some seemed to enjoy their work, but most said it was a sort of last resort. They had children at home they have to feed and they hadn't been able to find any other work.
Still, it's important to note, no one we spoke with said they were being forced to do this work by another person despite our suspicions and their youthful looks.
Often, skeptics of the modern slavery issue will point to a story like this as proof that it doesn't exist, or that the problem is overblown.
But the absence of evidence is not evidence of its absence and the simple fact is; it is very hard to get deep enough into an underground criminal culture to find evidence of trafficking, especially in a single night.
It's equally difficult to convince a person who may be in that situation that it is safe and wise to speak openly with a foreigner.
In filming the documentary, "The Fighters," we witnessed the hard work of the Filipino government's Inter-Agency Council Against Trafficking, honest police officers and anti-slavery organizations like the Visayan Forum and International Justice Mission.
They are working to ensure that jaunts like the one we attempted aren't successful, not only for a night, but for good.