I told Rosa all this in fragments, but she listened patiently. That skill was the result of forty years as a priest, no doubt, but it was effective nonetheless.

I felt uncomfortable, though, when I talked of Tom and Morag. I knew how unhappy he was that I had come here; I felt I could sense his hostility all the way across the Atlantic.

“And now she’s come back to you,” Rosa said.

“So it seems.”

“Why, do you think?”

“I don’t know! I wish I did.”

“And do you want it to stop?”

I could answer neither yes or no; either would have been true, either a lie. “I want to understand,” I said at last.

She reached out. When her dry fingers touched the back of my hand I felt a jolt, almost like the static shock I felt earlier. “Try to be calm,” she said. “I just needed to be sure you were sincere.”

“Of course I’m sincere.”

“Well, now we both know that, don’t we?”

While she learned about me, I found out about her. Uncle George had told me something of Rosa’s story. During that meal I began to learn a little more.

She had been born in Manchester, England, as George had been, nearly ninety years ago. But when very small she had been sent to Rome, and given into the care of a Catholic fringe group called the Puissant Order of Holy Mary Queen of Virgins — the Order, as George referred to it. George himself had been so young he had forgotten he even had this second sister, until by chance he came across a photograph in the effects of his deceased father.

The Order was a teaching group. Among other things. Rosa had been raised by them, and when she grew up had gone to work for the Order.

When he was in his forties, George had discovered Rosa’s existence, and he went to Rome to look for her. This had coincided with some kind of crisis in the Order. The sequence of events had resulted in Rosa being expelled from the group, and for a time she faded from George’s life again.

It turned out that after her expulsion from the Order Rosa had stayed within Catholicism. She had gone to a seminary and eventually taken holy orders to become a priest. Now, I learned, she served a scattered parish that covered much of the northern suburbs of Seville, and poorer communities outside the city boundaries. She had been here for three decades, and she was still working, with no intention of retiring as long as her strength held out.

Her story struck me as strange, in those first tellings. The Order had been prepared to take her in because, it seemed, there was some deep and old family connection between the Pooles, my mother’s little nuclear family in Manchester, and the Order in Rome. But for a family to send away a child, for good, was a bafflingly painful thing to do. And then for the parents to lie about it to George, their son, to keep secret the very existence of a sister, seemed a terribly cold and calculating deception.

And then my own mother, that bit older than George, probably remembered it all. Had she never thought to tell George about Rosa, before he stumbled across the secret for himself? But my mother had never discussed any of this with me either. Generations are like that, I suspect; even though I was in my fifties my mother still kept her problems from me, as if I were a child.

Still, Rosa’s account of herself was a hollow story, I thought, a listing of events without real heart. I wondered how much more of it I would have to learn before I was done — and how much I really wanted to know.

“Are you a believer, Michael?”

“In the Christian God? I guess not. I’m sorry.”

“Don’t be. I’m not sure if I am, despite this.” She flicked her collar. “But I’m convinced that everything we humans do has some evolutionary purpose, or else we wouldn’t do it. And I believe that priests, and the witch doctors and shamans that came before them, have a crucial role to play, regardless of their theological justification.

“When I first came out of the seminary, and accepted my first post at a parish here in Seville, I imagined I would be strong enough to cope with what the job threw at me. After all I had been through some grueling experiences myself.” Her face worked briefly, but she didn’t elaborate. “I was wrong. I was shocked.

“I found I was a conduit, Michael. That was my role. A conduit into which people were able to flush their pain and their fear. And, believe me, there is plenty of that, even in this place where there are hardly any people left. I was nearly overwhelmed, a mote in a dust storm. But my seniors counseled me, and I came to understand my duty, which was to stand firm in the face of that great flooding of misery.”

I said cautiously, “And — experiences like mine? You’ve come across such things before?”

“My faith teaches us that the world is a subtler place than is revealed by our blunt senses, Michael. You have to believe that much, whether or not you buy the Christian explanation. And, yes, sometimes I have been exposed to experiences that you would describe as beyond the natural. You’re an engineer, aren’t you? You are probably uncomfortable that something so irrational is happening to you.

I never liked being pigeonholed. “I like to think I’m broader-minded than that,” I said.

“Well, perhaps you are. You’re here, after all. And now that I’ve met you I’m quite prepared to believe that you aren’t mad, or delusional, or a liar; something really is happening to you. What we must work out is what it means.”

“So what do we do?”

“Why, nothing. You say that Morag comes to you, without your choosing it. Then let her come to you again, and we will see what we will see.”

“And if she doesn’t come?”

She smiled; I thought I detected a trace of contempt in her expression. “Then you’ve nothing to worry about, have you?”

We had been drinking wine. It was fortified, a kind of sherry, but light and very dry, with a strange salty tang. Rosa took hers with a little water. She said the wine was called manzanilla, and was matured only in a town to the southwest, where the Guadalquivir met the Atlantic Ocean, which perhaps explained the subtle saltiness.

Rosa opened the glass doors to her balcony, and we walked out. We were looking west, where the sky was still stained by the dusty sunset, but at the zenith bone-white stars were starting to appear. The air was cooling, but it was still so dry it burned my throat. There were few lights to be seen in the darkened landscape of buildings, homes and shops, restaurants and bars, and a kind of dense silence settled over the town, a silence so rich it seemed to roar, dully, like the blood in my ears.

Rosa had brought a little jug of water with her, and now and again she tipped some into her wine. “You are sure you don’t want any of this?… Customs are changing, you know. In some houses these days good fresh water is presented as the finer drink. You wine your water rather than the other way around!” She held up the jug to the sky, peering into the water; it was slightly cloudy. “But this wouldn’t pass muster in the best households. Desalinated ocean water, pumped up here from Almunecar on the coast.”

“Water’s scarce here.”

“Of course. It’s the same all around the planet. A midlatitude, midcentury blight,” she said. “Spain is a big square box of land and mountains, and for twenty years, I suppose more, it has been drying out, desiccating. Luckily for the Spanish they already had extensive experience of water conservation, desalination, all the other disciplines of drought. I remember when I first came here there was a vast scheme to water the Almeria, the desert region to the east. It would be the world’s greatest tourist resort, greater than Florida, with golf courses and holiday homes by the tens of thousands. And they promised to make plants and grasses so salt-resistant you could irrigate them with untreated seawater. Ha! Now it is all gone, and we are plagued by dust.”