Border-patrol agent Nate Lagasse is sitting quietly in his Toyota Land Cruiser about three miles west of a small Arizona town on the Mexican border, following a group of 12 immigrants through his night-vision goggles. He radios directions to three colleagues, who are out in the mesquite on foot and closing in on the aliens. "They don't even know we are here yet," whispers Lagasse, who has turned off his headlights and allowed his truck to roll to a halt without hitting the brakes. "It's just like hunting."
Something alerts the aliens, and they hit the dirt, probably at the order...