Marijuana smoke clings to the beams of the ceiling. A red light pulses through the room, revealing fleeting glimpses of the men at the bar who stand without drinks in their hands. The music is loud so Mercado draws in close, ‘Those guys at the bar, they’re the coyotes (people smugglers).’ I look up briefly and catch the eye of a thickset man in denim. I scoop up my drink and he holds my gaze, though he loses interest as a dishevelled man with a backpack on his shoulder approaches.

I am on the western edge of the United States–Mexico border to understand more about the most publicised and most crossed border in the world. I want to understand how 11 million unlawful immigrants, at a conservative estimate, have passed into the United States, crossing the line in the dirt that separates the developing from the developed world. In 2012 that line saw 364,000 apprehensions along the border, a mere fraction of those who make it across­—a number it is impossible to know. I want to see how one of the world’s most notorious borders handles this situation and to gain some perspective on our own frontier issues in Australia, as we deal with the hysteria surrounding refugee arrivals, with constant claims of a ‘detainee deluge’ and the thousands ‘invading’ our country as boat people and asylum seekers.