‘Your prime minister must never know,’ said the sheikh seriously. ‘I do not want to give offence or distress to a guest, no matter what happens.’

‘He won’t know,’ I promised him.

Dinner was over, and the sheikh said he would sit in the foyer to wait for his car. Harriet and I agreed we would like a walk before finding taxis to take us to our homes. It was a beautiful evening, and the sky was still light. We walked slowly along Piccadilly together.

‘What a good evening,’ said Harriet. ‘I do love the sheikh. I will miss him.’

‘Won’t you see him next time he comes to Glen Tulloch?’

‘He won’t be coming back for a long while. He wants to stay and attend to the future success of the salmon project, and he knows the launch is just the beginning and there will be many, many problems and crises to deal with after that. And you, I hope, will go there and help whenever he needs it.’

‘Of course I will,’ I agreed, ‘but won’t you?’

‘I don’t know,’ said Harriet. ‘Maybe it’s time for me to move on. I’ve put a lot of myself into the project, and really there isn’t that much more for me to do. And Robert’s death, as you know better than most people, has been a very heavy blow. I just need to take stock. I need a break.’

‘Of course you need a break, Harriet,’ I told her. ‘No one deserves it more than you.’ We had stopped by the railings that ran alongside Green Park, absorbed in our conversation. The evening traffic was still busy. The park gates were still open, so we stepped inside for a moment to get away from the noise of traffic.

‘But you’ll come to the Yemen for the great day?’ I asked.

‘No, Fred, I won’t,’ said Harriet. ‘I will be there for you in spirit, but not in the flesh. The truth is I couldn’t bear it if something went wrong. I couldn’t bear another disaster. I’d rather be here, and then if I don’t want to see what’s happening I can just switch off the television until it is over.’

‘But there won’t be a disaster,’ I said.

‘I know there won’t,’ she said. ‘I know you’ve done everything you can to make this work, and I know that if anyone can pull this off, it’s you. But…my head tells me all of that, and my heart tells me something else.’

I stared at her. She stood close to me, her face white in the faint street light, still beautiful to me despite the lines of strain.

‘But, Harriet…’

‘I’m going away,’ she said, ‘the day after the project is launched in the Yemen. I’ve got leave of absence from Fitzharris for six months, and they’ll keep my job open in case I want it back. At the moment, I don’t think I will.’

‘But, Harriet…’ I said again, hopelessly.

Tears began to roll down her cheeks. It was too much. I took her in my arms and kissed her. At first she let me hold her and responded briefly to my kiss, but then she went limp. I let her go and she stepped away.

‘Don’t, Fred,’ she said.

‘But when will I see you again?’ I asked. ‘You know how I feel about you. I can’t help it, and I’m so sorry to have done what I just did, so soon after Robert, but I can wait. I’ll always wait for you, if you just say that one day there could be some hope for me.’

‘There isn’t any hope,’ she said in a dull voice, ‘not for you, not for me.’

‘But, Harriet,’ I said again, ‘you know what happened at al-Shisr. Didn’t that mean anything to you? It meant everything to me. It changed my life.’

‘I can’t see you again, Fred,’ Harriet told me, her voice still not quite steady, ‘and whatever happened, or didn’t happen, at al-Shisr was just a dream you had. I only remember a dream. And now we’re in waking life and the reality is you are married to Mary. You are fifteen or twenty years older than me, and we come from completely different worlds. I am still grieving for Robert, and I have to rebuild my life without him. And I have to do it without you or anyone else. It just isn’t possible there could ever be more between us. We’ve been friends-you’ve been the best friend I could have ever wanted-but I can’t give you any hope that there would ever be anything more.’

I turned away from her for a moment. The lamps in the park had just come on and must have dazzled my eyes, for they were watering. With my back to her I said, ‘I understand, Harriet. You’re right.’

She came up to me and put a hand on my shoulder. ‘I know I’m right. I hate myself for it, but it’s the truth. Come on, Fred, help me find a taxi.’

The interview resumed the following morning.

Interrogator:

Describe the events that took place in the Wadi Aleyn.

Alfred Jones:

The thing to realise about the Wadi Aleyn in August was that it was hot. It was hot beyond the imagination of anyone who has never been in the desert. The sun in the Wadi Aleyn was hotter than a dozen English suns. It burned down out of a milky sky, and the rocks were hot to the touch. The thought of a salmon surviving unprotected in that heat, in that incandescent light, was beyond belief. And yet they had to.

I had been a dozen times around the holding basins, which were slowly filling with water from the aquifer. The oxygen bubblers were working rhythmically at the sides. Water temperatures were being held stable at around 21 degrees Celsius and we thought we could drop that three degrees when the rains came. I had checked everything, and rechecked, and I knew I was driving the project teams, and myself, mad with my constant questioning. In the end I took myself off up the wadi. I wore a hat and covered myself with sun cream, but still I felt as if I was in a furnace.

This was the time before the rains came. Out in the desert sandstorms would build themselves on giant thermals. In the towns and villages people and animals moved about as little as possible in the heat of the day, found shade wherever they could and waited for the sun to go lower in the sky.

In the wadi the heat and airlessness were almost too much for me. There was a sense of something building, like a distant storm. When the rains came, we would make a call to the UK. Within twenty-four hours of that call, the fish at McSalmon Aqua Farms would be taken from their cages and placed in the flying aquariums, which is what everyone called the stainless-steel pods in which they would be flown out to the Middle East. In another twenty-four hours they would be ready for delivery into the holding basins. And then we would wait. We would wait for the waters of the Wadi Aleyn to flow, and as the flow grew from a trickle to a stream, from a stream to a river, we would open the sluice gates. And then we would see.

I found I was breathing hard and feeling a little dizzy. The heat was getting to me. There was no one within a mile of me, at least no one I could see. I found a flat stone in the shade of overhanging cliffs that was not too hot, and sat on it, trying to recover myself. I took a Thermos of cold water from my backpack and took a pull on it. After a moment I felt a little better.

The silence around me was absolute. Even the buzzards were quiet. Rock walls stretched above me. There was not a single sign of vegetation. What did the goats live on now, the goats belonging to the girl further up the wadi who had once brought us water?

I tried not to think about Harriet, but she kept intruding into my thoughts, as real as if she was standing in front of me. I could almost see her, like a ghost, now gaining substance, now fading again, her voice, thin and insubstantial, saying, ‘There isn’t any hope, not for me, not for you.’

I thought about the sheikh saying, although I could not remember his exact words, ‘Without faith, there is no hope. Without faith, there is no love.’

Then in a moment, in that vast space of rocks and sky and scorching sun, I understood that he had not meant religious faith, not exactly. He was not urging me to become a Muslim or to believe in one interpretation of God rather than another. He knew me for what I was, an old, cold, cautious scientist. That was what I was then. And he was simply pointing out to me the first step to take. The word he had used was faith, but what he meant was belief. The first step was simple: it was to believe in belief itself. I had just taken that step. At long last I understood.