It's 4.30am and huge spotlights illuminate the runway. An ageing Boeing-737 - paint peeling, no name and no identification - is ready for loading at the cargo area of the George Bush international airport in Houston, Texas.
Federal agents carrying shotguns form a perimeter guard inside a chain-link fence topped with razor wire. Three sleek white buses with the words Homeland Security written on the side roll to a stop.
Steel grates cover the windows. The driver is protected by a cage: armoured doors and thick glass separate him from his passengers - 42 prisoners.
As a I step into the bus a roar builds from the back.
Men's voices, thick Spanish accents: "Mother**** Yo! I am going to kill yooouuuuuuuuuuuuuuuuuuuuu!"
The prisoners include Mexican Mafia gangsters and members of the notorious MS-13, "Mara Salvatrucha", a gang known for tattooing their faces and slaughtering their enemies. Each wears handcuffs and thick metal ankle chains so tight he must take baby steps to avoid falling. A waist chain pulls his hands so he cannot even scratch his face.
As the prisoners leave the bus, burly security guards form two rows and search each convict for hidden weapons.
A guard aims a flashlight into prisoners' mouth. Shoes are inspected, investigated and pulled apart. ("There is a kind of sneakers that have metal in them," a guard later tells me. "The guys could make a knife out of it.")
Next to the prisoners are three rows of clear plastic bags. These are the inmates' possessions. Inside one bag is a Bible, toothbrush, letters and a red belt buckle, cow horns raised, testament to a macho swagger that has now been reduced to the clank of chains, and the shuffle of sneakers with no laces. To prevent suicide, belts and shoelaces are removed for the flight.
Mexicans are loaded first aboard the aircraft. These are not typical hard working Mexican immigrants. This is the 1 per cent who crossed the line and became criminals - robbing, attacking and stealing their way to the American Dream.
One by one, the prisoners shuffle up the boarding stairs. They are directed to stay seated, keep quiet and obey orders. Instead of passport numbers, the passenger manifest on this flight lists their most recent crime - drug trafficking, indecency with a child, assault, drunk driving, drug sales, theft, assault, aggravated assault, and sexual assault ... it's a long, ugly list.
"I would rather die of hunger in Mexico, than come back here," says 25-year-old Carlos Rojas, as the plane loitered on the runway.
"Look how they have us." He shakes the chains: "Like a dog."
"I feel like a slave," complains another. "The only thing they didn't do is put a chain around our neck, I know we broke the law, but this is too much."
Rojas complained about the huge number of raids organised by ICE, the US Government's lead immigration police. "There are many more raids now. Roadblocks. On the highway, at work, everyone is getting caught."
* * *
What to Rojas is a surge of arrests is a multi-year plan by the US Government to arrest and deport an estimated 11 million illegal immigrants.
With operations such as Operation Community Shield, targeted at transnational gang members and the Criminal Alien Programme, which takes illegal immigrants from jail to deportation, the Government last year removed 110,000 foreigners who committed crimes.
A new plan calls for spending up to US$3 billion ($4.8 billion) to deport at least 1.4 million criminal immigrants.
The deportation flights are organised by the US Immigration and Customs Enforcement agency. Known as "ICE", the agency, part of the sprawling Department of Homeland Security, employs 7000 officers around the US. One of its tasks is to get foreign criminals out of America.
As the plane climbs off the runway and banks skyward, the prisoners scream like children on a roller-coaster - for many it is their first time on an aircraft. All stare out the windows. Some squeeze their eyes shut. Some pray. "Look how little the cars are!" says a man charged with armed assault sitting behind me. He is fascinated by the bird's eye view of Houston. "This is much better than the bus."
"We do not have medication for nausea," announces the flight attendant over the cabin loudspeaker. "If you want to vomit, please advise a member of security."
"The Salvadorans are the most rowdy, they scream, throw their food around the plane and cheer like mad when they get home," says one federal agent. "But we have total control of this."
Still, he asks me to sign a legal release, a document that legally is called "Hold Harmless" and in effect means - whatever happens aboard and whatever happens to you, it ain't our fault.
* * *
On board, prisoners are reluctant to speak with a reporter. One, Pablo Morales, a 32-year-old from El Salvador, tells his story, or at least his version of it. "They caught me with cocaine. But just a bit. They call it criminal ... I was driving and on the passenger side, they found a little teeny bag of cocaine; maybe a friend left it there?" Even Pablo does not sound convinced by his weak excuse. "It was a tiny bag, and they call that a crime!"
When asked about the infamous Mara Salvatrucha street gang, Morales twists his face into a scowl - "They should be all prisoners, those guys are bad boys. They are like a cancer on society."
But what Morales does not know is that two rows behind him, in the middle seat is Joselito Hernandez, a 24-year-old member of MS-13, convicted and now being sent home.
I approach Joselito. As I begin to interview him, the tension rises. The other criminals begin shifting about; I can hear the rattle of chains behind me, wondering if I get jumped, how long before the guards will rush down the aisle to pull the gangsters off. And even more important - after they pull them off, what will be left of me? I look at the burly security guards from Akal, the private security firm. The security guard's shoulders are about two seats wide and he is right next to me.
Joselito's not talking much, a few words here and there, but he refuses to provide details of his criminal life. Nada. ICE provides me with his arrest records and the background details of his local clique; a neighbourhood gang that agents believe is linked to the international MS-13 organisation.
As the flight levels out, the prisoners are allowed under escort to use the bathroom. A phalanx of guards watch, making sure that prisoners - 124 of them, half Mexicans and half Salvadorans - can't attack an enemy or start a fight.
With rival gangs and rival nationalities aboard, the 15 unarmed guards are on high alert. They have enough muscle power to smash the convicts into submission should trouble erupt. "They are very protective of the cockpit," the copilot told me. The convicts tend to lean back, stare at the ceiling and plot their return to the United States.
I am invited into the cockpit. Here the calm view of the Gulf of Mexico drops my blood pressure.
Headed back to the passenger cabin, I see a nurse aboard, dishing out blood pressure pills to three prisoners - their blood is pumping too hard. Oxygen bottles are at the ready for it is common for inmates to pass out from the stress of these flights.
The first flight was a 30-minute hop from Houston to the coastal city of Harlingen, where the Mexicans were unloaded and packed on to an armoured bus. Their journey was short - dropped at the border, they might be in Houston by dinner time.
For the Salvadoreans, the day was just beginning. Like a poor man's bus service, these flights often skip about the US until there are no seats left. After dropping the Mexicans , the flight continues to Georgia where dozens more Salvadorans are waiting. As we begin the four-hour flight to San Salvador, the capital of El Salvador, I interview more prisoners.
"I will be back here [US] in less than a month," one tells me as the plane crosses the Gulf of Mexico. "They tell me that if they catch me again, I will get 20 years, but I am still going home."
When this man says "home" he means South Texas, which today resembles Little Mexico given the huge Hispanic population, endless rows of shacks and the poverty-induced chaos that leads to high murder and assault numbers.
Four other inmates detail their stories of crime, their years in prison and plans for the future. They are determined to escape El Salvador as fast as possible. They will return to the US on what analysts describe as the immigration "conveyor belt". Critics of the deportation trips worry that the "Conair" flights help gang members set up remote branches of their empire. The MS-13 is now nationwide in the US and dominant in El Salvador and Honduras.
Powerful Mexican gangs working both sides of the border include the Mexican Mafia, the Texas Syndicate, Tango Blast and Los Bandidos.
When the plane approaches El Salvador, the men begin cheering, hooting and celebrating.
"They talk back [to us] and say, 'I'm going home, nothing you can do to me now'," explains Brett Bradford, the agent in charge of the flight.
At the airport, the prisoners march down the gangway into El Salvador's thick tropical heat. Hands above their heads, they form a line between two rows of policemen and move towards a grove of palm trees.
The photographer snaps a tattooed criminal. The man stiffens, his shackled hands clench together, his head snaps away, trying to hide his identity. Then he raises his hands and forms a gun barrel, he fires an imaginary gun and whispers "puuffffffffffff!"
Had this been the open streets of Houston, Mexico City or San Salvador and not a law enforcement prisoner exchange, the story would have a familiar ending - a few shots, a pool of blood and another dead journalist.