We’re zigzagging now, heading down deep into another arroyo, which means sometime soon we will have to climb out again and every muscle quails at the thought. There are black specks in front of my eyes. When I dare to look at the sun it sizzles angrily back at me like a burning cigarette tip.

Finally, I sense a break in the rhythm. Benjamín has stopped. Ahead of us, balancing on a rusting tripod of legs stands a blue tank with the word Agua painted on the front. I have a moment of wild joy, and then I see them. Bullet holes. Dozens of them.

Benjamín says nothing, so neither do I. Instead I try the radio again but now there’s no static, no noise, nothing.

Benjamín takes it from me and fiddles with the knobs.

‘Dead,’ he says.

In the spartan shadow of the water tank we wait for Duval, for Toribio Romo, for someone to come. One hour, two. After that I stop counting. Benjamín’s shoulder looks no worse, but I wonder how much more quickly the body dehydrates when wounded. How much further he will be able to go because today there is to be no miracle.

‘How long to Temerosa?’ I say eventually.

Benjamín doesn’t reply. Very slowly he pushes back onto his feet.

‘How far?’

‘Not far.’ He lies and smiles his broken smile.

Foot after foot. Step after step. I start to think about Estella and the baby and how it ended for both of them. For a surreal and muddled moment I think I must surely be the reincarnation of this girl. How else can the two of us be in love with the same man, be led over the border by the same man, be raped by the same man, and I wonder why fate has sunk her teeth into my ankle with such an obdurate bite . . . Then I pull myself together. I am not Estella and I will not lie down and I will not die here in the desert.

Things unseen tear at my legs: burrs, seeds, thorns.

I barely notice them any more. With every step, I walk closer to my children. There are tricks you can invent to keep your feet going. I find rhythms, random beats of songs. I mark the ground from one desiccated clump of mesquite to the next and start counting them, twenty clumps to the mile. I cross-reference footsteps with miles with mesquite bushes, looking for some neat algebraic answer which might lead to survival but the only thought that keeps coming to me is how vast the world is, and I feel lonelier than I ever thought it possible to feel.