'It's our job to stop that dream': the endless, futile work of the Border Patrol.

• Author: Politzer, Malia

BORDER PATROL AGENT Elizier Vasquez gets out of his car on Elephants Head Road, a smear of dirt and gravel wedged between two slices of desert. His eyes comb the rust-colored Arizona dirt that stretches for miles to the north, south, and west, its stark beauty marred by scattered piles of trash. A few miles to the east of us is High-way I-19, which shoots straight from Nogales to Tucson, and past that there's more desert. We came here from the U.S.-Mexico border, about 25 miles to the south. The drive took less than 30 minutes. Walking, Vasquez tells me, would have taken about three days.

"Look at all the trash left by illegal aliens," he says, navigating through a knee-high pile of old clothes. I trip on a dusty sweatshirt; it catches in the branch of a mesquite tree and rips, brittle and weathered. Empty water jugs lie beneath the desert shrubs, the plastic brittle and broken from the heat. We navigate through backpacks, clothes, empty tuna cans. Shoes, some with soles worn out, lie in piles among the tangles of cactus and mesquite.

"We call these lay-up spots," Vasquez says in a low voice. "Illegal aliens rest here while they wait for their rides. Most are known spots. Probably we'll find the illegals sleeping under a tree. If not, they've probably already been picked up by their smugglers"

Lay-up spots are scattered throughout the desert along the many paths worn by the feet of illegal entrants, hundreds of sad little Ellis Islands baking under the Arizona sun. Migrants rest and clean up there, dumping everything left over from their three-day hike to rot in the desert. The spots started showing up in Arizona around 1999, after a crackdown in border towns steered those who wanted to enter the United States illegally toward the open desert.

Patrolling lay-ups is pointless. As soon as smugglers get wind that agents are watching one, they'll bring their charges to another spot a few miles down the road. It's an endless game of cat and mouse.

It's the game Vasquez lives for--though he doesn't always love it. Originally from Puerto Rico, the agent worked as a rum salesman before joining the Border Patrol in 2000 to pursue a childhood dream. "I wanted to go into law enforcement," he explained to me earlier in the day. "You know the cliche that little boys either want to be firemen or policemen--I never grew out of that." He and his wife moved to Arizona to pursue a new future, leaving behind everything they'd ever known.

Some days it's good. The days he apprehends aliens who are actual criminals are the best, Vasquez says, because those days he knows he's made things a little better. Even so, he admits he thinks it's unlikely the Border Patrol will ever fully control the border. "We can get operational control," he says. "We can control it to a certain point, but due to the terrain it's almost impossible to seal it off to all illegal activity."

And some days aren't so good. Like when he comes upon women with infants trying to cross the region aptly nicknamed "the death corridor."

Welcome to the Arizona desert, where smugglers and the Border Patrol are locked in a daily struggle. One group looks for clever ways to smuggle goods and people across the border; the other looks for cleverer ways to stop them. Caught in between are the migrants, for whom the outcome can mean the difference between life and death.

Vasquez is trying to teach me the rules, but the game's already over. The Border Patrol lost a long time ago.

"We don't have any specifics on the call, so we don't know who we might run into here," Vasquez whispers as he pushes past the spiny black branches of a mesquite tree. "Could be a group of U.S. citizens out on a hike. Could be a group of drug-smuggling aliens. Could be a group of aliens in distress. We don't know, so we have to be careful"

Lost in the Desert

A Tucson-sector Border Patrol public relations officer, Jesus "Chuy" Rodriguez, later tells me that of all federal agents, members of the Border Patrol are the most likely to die in the line of duty. The claim is hard to substantiate, but it's certainly true that border violence has risen sharply in recent years. Attacks on agents more than doubled between 2004 and 2005, from 374 to 778, according to congressional testimony last March by U.S. Customs and Border Protection Commissioner T.J. Bonner. People throw rocks, bricks, and Molotov cocktails at the agents. They shoot them. They run them down.

As Bonner noted, the escalation in violence is linked directly to enhanced enforcement efforts at the border. Forcing migration into the open desert increases the cost associated with crossing, Bonner told Congress, squeezing out small-time smugglers and increasing violent struggles to control "lucrative smuggling operations" He added that "although much of this violence is directed at rival organizations, there is an inevitable spillover that touches innocent civilians and law enforcement officials on both sides of the border."

For agents like Vasquez, the thirtyish father to a baby girl, that means taking extra care. He walks a few steps in front of me, motioning at me to stay behind him.

We find the men we are looking for a few moments later. There are four of them, their clothes and backpacks covered in a fine layer of red dust. They put their arms up in surrender when they see Vasquez. He approaches them casually, speaking calmly.

"Do you have papers?" he asks in native Spanish. "Are you all Mexicans?"

A middle-aged man in dark green pants and a dusty blue cap singles himself out as the spokesman. "We're from Hidalgo," he says. "Illegal. I'm a farmer. So is he." He indicates one of the others with his chin. One is a carpenter, he tells us; another works in construction. "We're just here to work--we have friends in Atlanta who will give us jobs. We're not criminals."

"How long have you been walking?"

"Three days. Our coyote attacked us the first day. Shoved a revolver in his face and took everything." He jerks his head...