‘He’s a public letter writer, an evangelista,’ Duval explains, then smiles when I come over all dreamy at the idea. ‘It’s nowhere near as romantic as it looks. Her husband has probably been seduced by the extra green-backs and decided to stay in el Norte. He’s written to tell her that he has a brand-new American family and he’s never coming home, and she’s writing to tell him to rot in the hottest part of hell; but yes, I like it too.’ And I look up to find him smiling down at me.

‘I love this town!’ I say. ‘I love the border. I may easily live here forever.’

Duval takes a strand of hair and tucks it behind my ear. ‘And you wouldn’t be bored?’

‘I’d have my three wishes, remember? I’d be painting giant masterpieces or composing symphonies.’

‘And you wouldn’t be lonely?’

‘I’d have a lover.’

He raises an eyebrow. ‘What kind of lover?’

‘An elusive one. One who’d turn up from time to time, when I least expected him.’

‘Wouldn’t that be very inconvenient?’

‘Not at all.’

‘What if he turned up at a bad moment – say, when you hadn’t washed your hair or the house was untidy?’

‘My lover would have impeccable timing.’

Duval smiles. ‘And what would he be doing, this elusive and punctilious lover of yours, when he wasn’t with you?’

‘Oh, you know, riding across the land, a fugitive, an avenging angel, doing what he had to do to feel free, but from time to time he would dream of hearth and home and then he would come to me and he would take me riding at night and instruct me in the curious ways of cacti.’

‘But what if he is doomed always to be a fugitive?’

‘Then he risks being lonelier than I ever could be.’

‘Poor man.’ He takes my hand and examines the end of each finger. ‘If only he had the memory of last night to live on, he might never be lonely again.’

I smile and I think of all the things I want to say to this man and I try to work out why I feel the way I do about him, but it just seems easier to sit there, our shoulders touching, his hand heavy over mine, as the light deepens then fades and the shadows lengthen.

It’s well after eight o’clock when a wiry little Mexican of incalculable age sidles through the encroaching dusk towards us. He sits down on the far end of our bench, bouncing his knee up and down with such vigour it looks as though he’s in danger of pogo-ing off across the square again.

‘Reuben,’ he announces finally, packing so much nervous intensity into the one word I worry he might have no energy left to speak ever again.

‘How are you doing?’ Duval asks him.