The Alubia is on the east side of town where the houses are built on the steady incline of a hill. Down at the bottom stands the wall. A double layer of corrugated green steel which slices the rival citadels of Nogales Sonora and Nogales Arizona and their inhabitants into two halves. Those with the jam, and those without. I want to go down and take a look at it but before we even get close we’re surprised to run into Reuben again. This time he’s coming up the hill towards us, dancing on the toes of a rasta dressed in a sleeveless camouflage vest with body mass to equal a submarine and great muscled arms hanging by his sides like polished black torpedoes. Undaunted, Reuben talks animatedly up at him but the rasta merely flicks his dreads in irritation and lengthens his stride, causing Reuben to redouble his efforts not to be trampled underfoot. He passes us like this, apparently unaware of our presence, and we’re staring after him unsure whether to laugh or race to his rescue when he shoots back round the corner and blags another $3, explaining that someone, though of course not the guy he’s with right this second, is hassling him to repay a debt and will surely break his legs if he doesn’t show.

‘He’s not the only one,’ Duval says, handing over the money.

‘Hey, man, relaaax,’ Reuben wheedles. ‘I’ll show up, don’t worry, you can count on Reuben. Everybody can count on Reuben.’