The air is thick with heat and dust,

and it's hard to breathe.

I can feel the brush of sweaty bodies passing me in the darkness,

but I can't see much else.

I hear voices talking, but mostly,

the shaft is this cacophony of men coughing,

and stone being broken with primitive tools.

Like the others, I wear a flickering, cheap flashlight

tied to my head with this elastic, tattered band,

and I can barely make out the slick tree limbs

holding up the walls of the three-foot square hole

dropping hundreds of feet into the earth.

When my hand slips, I suddenly remember

a miner I had met days before

who had lost his grip and fell countless feet

down that shaft.

As I stand talking to you today,

these men are still deep in that hole,

risking their lives without payment or compensation,

and often dying.

I got to climb out of that hole,

and I got to go home,

but they likely never will, because they're trapped in slavery.

For the last 28 years, I've been documenting indigenous cultures

in more than 70 countries on six continents,

and in 2009 I had the great honor

of being the sole exhibitor at the Vancouver Peace Summit.

Amongst all the astonishing people I met there,

I met a supporter of Free the Slaves, an NGO

dedicated to eradicating modern day slavery.

We started talking about slavery, and really,

I started learning about slavery,

for I had certainly known it existed in the world,

but not to such a degree.

After we finished talking, I felt so horrible,

and honestly ashamed at my own lack of knowledge

of this atrocity in my own lifetime.

And I thought, if I don't know,

how many other people don't know?

It started burning a hole in my stomach, so within weeks,

I flew down to Los Angeles to meet with the director of Free the Slaves

and offer them my help.

Thus began my journey into modern day slavery.

Oddly, I had been to many of these places before.

Some I even considered like my second home.

But this time,

I would see the skeletons hidden in the closet.

A conservative estimate tells us

there are more than 27 million people enslaved in the world today.

That's double the amount of people taken from Africa

during the entire trans-Atlantic slave trade.

A hundred and fifty years ago,

an agricultural slave cost about 3 times the annual salary of an American worker.

That equates to about $50,000 in today's money.

Yet today, entire families can be enslaved for generations

over a debt as small as $18.

Astonishingly, slavery generates profits

of more than $13 billion worldwide each year.

Many have been tricked by false promises

of a good education, a better job,

only to find that they're forced to work

without pay, under the threat of violence,

and they cannot walk away.

Today's slavery is about commerce,

so the goods that enslaved people produce have value,

but the people producing them are disposable.

Slavery exists everywhere, nearly, in the world,

and yet it is illegal everywhere in the world.

In India and Nepal, I was introduced to the brick kilns.

This strange and awesome sight

was like walking into ancient Egypt or Dante's Inferno.

Enveloped in temperatures of 130 degrees,

men, women, children, entire families in fact,

were cloaked in a heavy blanket of dust,

while mechanically stacking bricks on their head, up to 18 at a time,

and carrying them from the scorching kilns

to trucks hundreds of yards away.

Deadened by monotony and exhaustion,

they work silently,

doing this task over and over

for 16 or 17 hours a day.

There were no breaks for food, no water breaks,

and the severe dehydration made urinating pretty much inconsequential.

So pervasive was the heat and the dust

that my camera became too hot to even touch and ceased working.

Every 20 minutes, I'd have to run back to our cruiser

to clean out my gear and run it under an air conditioner to revive it,

and as I sat there,

I thought, my camera

is getting far better treatment than these people.

Back in the kilns, I wanted to cry,

but the abolitionist next to me quickly grabbed me and he said,

"Lisa, don't do that. Just don't do that here."

And he very clearly explained to me

that emotional displays are very dangerous in a place like this,

not just for me, but for them.

I couldn't offer them any direct help.

I couldn't give them money, nothing.

I wasn't a citizen of that country.

I could get them in a worse situation than they were already in.

I'd have to rely on Free the Slaves

to work within the system for their liberation,

and I trusted that they would.

As for me,

I'd have to wait until I got home

to really feel my heartbreak.

In the Himalayas, I found children carrying stone

for miles down mountainous terrain

to trucks waiting at roads below.

The big sheets of slate were heavier

than the children carrying them,

and the kids hoisted them from their heads

using these handmade harnesses

of sticks and rope and torn cloth.

It's difficult to witness something so overwhelming.

How can we affect something so insidious,

yet so pervasive?

Some don't even know they're enslaved,

people working 16, 17 hours a day

without any pay,

because this has been the case all their lives.

They have nothing to compare it to.

When these villagers claimed their freedom,

the slaveholders burned down all of their houses.

I mean, these people had nothing,

and they were so petrified, they wanted to give up,

but the woman in the center rallied for them to persevere,

and abolitionists on the ground helped them get a quarry lease of their own,

so that now they do the same back-breaking work,

but they do it for themselves, and they get paid for it,

and they do it in freedom.

Sex trafficking is what we often think of when we hear the word slavery,

and because of this worldwide awareness,

I was warned that it would be difficult for me

to work safely within this particular industry.

In Kathmandu, I was escorted by women

who had previously been sex slaves themselves.

They ushered me down a narrow set of stairs

that led to this dirty, dimly fluorescent lit basement.

This wasn't a brothel, per se.

It was more like a restaurant.

Cabin restaurants, as they're known in the trade,

are venues for forced prostitution.

Each has small, private rooms,

where the slaves, women, along with young girls and boys,

some as young as seven years old,

are forced to entertain the clients,

encouraging them to buy more food and alcohol.

Each cubicle is dark and dingy,

identified with a painted number on the wall,

and partitioned by plywood and a curtain.

The workers here often endure tragic sexual abuse

at the hands of their customers.

Standing in the near darkness, I remember feeling this quick, hot fear,

and in that instant, I could only imagine

what it must be like to be trapped in that hell.

I had only one way out: the stairs from where I'd come in.

There were no back doors.

There were no windows large enough to climb through.

These people have no escape at all,

and as we take in such a difficult subject,

it's important to note that slavery, including sex trafficking,

occurs in our own backyard as well.

Tens of hundreds of people are enslaved in agriculture,

in restaurants, in domestic servitude,

and the list can go on.

Recently, the New York Times reported

that between 100,000 and 300,000 American children

are sold into sex slavery every year.

It's all around us.

We just don't see it.

The textile industry is another one we often think of

when we hear about slave labor.

I visited villages in India where entire families

were enslaved in the silk trade.

This is a family portrait.

The dyed black hands are the father,

while the blue and red hands are his sons.

They mix dye in these big barrels,

and they submerge the silk into the liquid up to their elbows,

but the dye is toxic.

My interpreter told me their stories.

"We have no freedom," they said.

"We hope still, though, that we could leave this house someday

and go someplace else where we actually get paid for our dyeing."

It's estimated that more than 4,000 children

are enslaved on Lake Volta,

the largest man-made lake in the world.

When we first arrived, I went to have a quick look.

I saw what seemed to be a family fishing on a boat,

two older brothers, some younger kids, makes sense right?

Wrong. They were all enslaved.

Children are taken from their families

and trafficked and vanished,

and they're forced to work endless hours on these boats on the lake,

even though they do not know how to swim.

This young child is 8 years old.

He was trembling when our boat approached,

frightened it would run over his tiny canoe.

He was petrified he would be knocked in the water.

The skeletal tree limbs submerged in Lake Volta

often catch the fishing nets,

and weary, frightened children are thrown into the water

to untether the lines.

Many of them drown.

In fact, I didn't meet one child, not one,

who didn't know another who hadn't drown.

For as long as he can recall,

he's been forced to work on the lake.

Terrified of his master, he will not run away,

and since he's been treated with cruelty all his life,

he passes that down to the younger slaves that he manages.

I met these boys at five in the morning,

when they were hauling in the last of their nets,

but they had been working since 1 a.m. in the cold, windy night.

And it's important to note that these nets

weigh more than 1000 pounds when they're full of fish.

I want to introduce you to Kofi.

Kofi was rescued from a fishing village.

I met him at a shelter where Free the Slaves

rehabilitates victims of slavery.

Here he's seen taking a bath at the well,

pouring big buckets of water over his head,

and the wonderful news is,

as you and I are sitting here talking today,

Kofi has been reunited with his family,

and what's even better,

his family has been given tools to make a living

and to keep their children safe.

Kofi is the embodiment of possibility.

Who will he become because someone took a stand

and made a difference in his life?

Driving down a road in Ghana with partners of Free the Slaves,

a fellow abolitionist on a moped suddenly sped up to our cruiser

and tapped on the window.

He told us to follow him down a dirt road into the jungle.

At the end of the road, he urged us out of the car,

and told the driver to quickly leave.

Then he pointed toward this barely visible footpath,

and he said, "This is the path, this is the path. Go."

As we started down the path,

we pushed aside the vines blocking the way,

and after about an hour of walking in,