‘So that’s why I haven’t got the passports with me,’ I conclude.

‘Have you checked your bag?’

‘No, but they’re not—’

‘Check your bag, please, ma’am.’

‘Look, they’re not in my bag, I know they’re not there.’

‘Are you saying you deliberately entered Mexico without a passport?’

‘Well no, I mean, yes, but—’

‘Mexico is an international border. Crossing an international border without a passport is a violation of US law.’

‘I understand, it’s just that – as I said – it was an emergency.’

‘Ma’am.’ He takes a step forward. ‘You drive into Mexico without a passport – you don’t come out again.’

‘Look, officer, can I just give you . . . this?’

He looks at the crumpled twenty in my hand. ‘What’s that?’

‘Oh, this?’ I look at the note as though relatively surprised to see it myself, ‘Well now, that’s a . . . well, it’s uh . . . money, actually . . .’

‘What’s it for?’

‘It’s, uh, well . . .’

‘Ma’am,’ he says very loudly, ‘I hope that money isn’t intended as some kind of bribe?’

I positively chortle with laughter and shrink further down into my seat. ‘Goodness me, of course not! It’s for, uh . . . you know . . . uh . . . for the toll!’

‘Pull over.’

‘Okay,’ I say wearily.

I turn on the engine and press down on the accelerator. A hand slams flat on the windscreen. With a look of utter contempt, the guard backs into the booth, presses the button and the spikes disappear into the ground. He waves at another official. ‘No passport.’ He shakes his head, as though this is the most incredible thing he’s ever heard in his career as a US customs official. I mean, problem with a passport! Geez, can you believe that such a thing could ever happen at an international border?

‘What’s going on, Mummy?’ Jack says in a small voice. ‘This must happen all the time, right . . .’ Apprehensively, I follow the new official into the customs building, Emmy in my arms and Jack tagging along at my heels. ‘There’s a mechanism for dealing with this kind of thing, I assume? I mean, people must get their passports stolen every day?’

‘No biggie, ma’am,’ the new official says kindly. He presses a button and the elevator doors open into a waiting room of sorts. A long counter at one end is divided by a perspex barrier behind which more agents are rifling through filing cabinets and checking paperwork. ‘Wait here,’ he says, pointing at an unoccupied chair.