For as long as I can remember, I have always been two people.

My earliest recollection is of myself as a three year-old boy, Danny—and at the same time as a girl of the same age, Cristina.

Another early memory is of playing in the rubble of the bomb-ravaged streets of London, when I asked a little boy, “Who will you be tomorrow?” He looked at me as if I were mad.

I took it for granted that everyone I met, everyone in the world, was two people like me: one day I was Danny Madison of 10 Milton Street, Barnes, London; and the next I would be Cristina Velásquez of 122a Carrer del Santuari, El Carmel, Barcelona.

I went to bed as Danny and woke up in the morning as Cristina.

When as Cristina I asked my mother who she would be tomorrow, she said, “Why, myself. Why do you ask?”

I told her about Danny, and I think she assumed I was making him up—a kind of imaginary friend.

As Danny, I asked my mother and father at breakfast one morning, straight out, “Why am I two people?” By this time I knew that no one else of my acquaintance experienced life quite as I did.

They exchanged a worried look. “What do you mean, Danny?” my father asked.

I explained about Cristina, and that tomorrow I would be her, and my mother said, “I think you’re imagining things, Danny.”

I intuited their concern, and decided never to mention it again.

• • • •

By the time we were seven years old, a year after the war had ended, we had worked out that we lived every alternate day as our other selves: that is, as Danny I lived the 1^st of January, say, and then as Cristina lived the 2^nd, with Danny resuming on the 3^rd, and so on.

Danny would go to sleep on the evening of the 1^st and wake up in the morning of the 2^nd as Cristina, lying in bed and gazing at the whitewashed ceiling of the small room she shared with her sister. He—or rather she—would stare at her small brown hands in amazement, the memories of herself as Danny the day before fresh in her mind, alongside her own memories of her previous day.

What happened to us in the meantime, on our alternate days, when I was not Danny, and then when I was not Cristina? Was there a mirror version of me that took over on these days? For some time I was drawn to this idea of an intangible other-me—an other-us—that swapped roles every night. But no, I knew it could not be so. I still had memories of those days: the Danny days when I was being Cristina, and vice-versa. And while those memories were somehow distanced from the more vivid memories of when I was in control, there was no suggestion at all that I was watching some other guiding personality taking over.

Eventually, I had to yield to my own experience and perception of this strange phenomenon: that one day I was Danny, and the next Cristina, and on those alternate blank days my bodies simply went through the motions, a ghost existence.

In any case, I tried hard not to dwell on the explanation, for it was hard enough simply to survive what was occurring, both psychologically and in any number of more practical ways. In the early days there was always a period of uneasy integration in the mornings, long minutes of adjustment as our twin psyches meshed and negotiated the management of “self.” Little by little, I as Danny would recede, take a back seat, and I would reassert myself as Cristina. In the evening Cristina would go to sleep and wake up the following day as Danny, and the period of assimilation would begin again, this time Cristina adjusting herself in Danny’s sensorium. As the years progressed, however, the switch-over became routine, no longer a cause of disorientation.

• • • •

As Danny, I grew up in a relatively affluent middle-class household: When my father returned from the war, he took up a teaching post at the local grammar school where my mother was secretary to the headmaster; I was their only child.

As Cristina, I was one of two girls brought up by my widowed mother—my father, a staunch supporter of the Esquerra Republicana de Catalunya during the Civil War, having vanished, presumed dead like so many after Franco came to power, soon after my birth. My mother was strict and controlling, and it is only with hindsight that I began to understand how this was dictated by her fierce desire to protect her two daughters in a time when perhaps 300,000 children of leftist families were abducted by the state. It is only with hindsight, too, that I came to understand that she must have paid for our upkeep by earning money in whatever ways a woman could in such punishing times.

I soon learned to compartmentalise my memories, so as not to arouse suspicion. As Cristina, I feared my elder sister, who bullied me and thought me strange: I once told her of my other life as Danny, and quite naturally she thought I was lying, and at the same time resented my vivid imagination and the freedom it allowed me to escape our harsh reality.

We were a strange composite, Danny and Cristina. With our dual existence, we shared a double upbringing: Danny, raised as a boy with an Arsenal-loving father, was obsessed with football; Cristina, brought up by an often-absent mother and a bullying sister, sought escape in clothes design and dance, drawn moth-like to the emerging fashion and arts scene in post-war Barcelona. In consequence, Danny showed an early predilection for cross-dressing and ballet—to which my remarkably liberal parents tried to turn a blind eye—and Cristina developed a strange interest in Arsenal football club.

Harder to explain, as Cristina, to my bemused mother was my fluency in English, and as Danny my even less explicable facility in Catalan. I told my Catalan mother they were teaching us English at school, and my English parents that I had a Catalan evacuee as a school friend—and I was able to furnish enough details from the life of this imaginary escapee from Franco’s Spain to convince them.

• • • •

One day, I as Cristina resolved to stay awake all night in an attempt to experience the moment of transition. I read until my eyelids began to droop, then got up to walk around the bedroom, trying desperately not to disturb my snoring sister. Then I returned to bed, repeating the cycle right through to the early hours.

Dawn came at five o’clock, and still I, Cristina, had not transferred to the mind and body of Danny, seven hundred miles away in London.

And then, on the stroke of six, I blacked out—and the next I knew I was blinking myself awake in Danny’s familiar bedroom with Cristina’s memory of the day before, and her attempt to remain awake, fresh in my mind.

We each tried the experiment again from time to time, always with the same result.

• • • •

For as long as I can recall, we knew that one day we should meet.

In my teens as Danny, I badgered my parents to take me on holiday to Spain, drawing their attention to the rise of what came to be known as the package holiday. Horizon Holidays’ package to the Costa Brava would take us tantalisingly close to Barcelona, but despite my persistence, I failed to persuade my parents. The idea of foreign travel was little more than a dream for me as Cristina, with my mother hard-pressed to put food on the family table, never mind afford foreign holidays.

• • • •

Because of our singular situation, we had developed a self-protective reserve, a hesitation when it came to making friends, of giving ourselves to others. This led to social isolation as we grew up, even loneliness—though of course we were never really alone, as we had each other, and our shared memories, as consolation. This was the paradox: we had each other, and yet on some fundamental level this was never enough.

As Danny, I found myself drawn to slight, gamin girls with dark hair and pale faces—while as Cristina I was attracted to tall, blond boys . . . which were something of a rarity in Spain.

Despite our reserved nature, we had girlfriends and boyfriends, and even thought we were in love from time to time, but these affairs never lasted. Our lovers accused us of being remote, of being unable to give ourselves fully, and we knew this to be true but could not of course explain the reason why.

In London, I did well at grammar school, and in time enrolled at university, winning a place at Cambridge to study languages and classics. In Barcelona, my education was hard-earned, but as Spanish society opened up in the 1950s—perhaps ironically under the influence of the tourist boom—I caught up at school and took up a place to study art and languages at the Universitat de Barcelona. We excelled, our doubled memories and linguistic abilities aiding and abetting our respective learning.

On graduating and finding jobs—Danny in publishing and Cristina in art restoration—we became for the first time financially independent and turned our minds to the idea of meeting each other for, as it were, the first time.

• • • •

We tried to fathom the paradox of our singular situation as we contemplated meeting.

As Danny, I would wake up on the morning of our rendezvous, my head full of Cristina’s memories of the day before as she took a flight to London and booked into an Earl’s Court hotel: I shared her excitement, her apprehension.

We would arrange to meet at eleven at Trafalgar Square. I as Danny would approach the slim, dark girl standing at the feet of the north western lion, staring at the Cristina I was and had been, knowing her intimately and yet never having been able to hold her in my arms.

The ache in my heart would be almost unbearable.

• • • •

On the day after Cristina flew to London, I awoke with memories as her the previous day still fresh in my mind. I recalled the novelty of the flight, foolishly proud that my reaction was one of excitement and curiosity rather than fear at the noisy, disturbingly flimsy-seeming aircraft. I recalled the subsequent journey to the hotel, and the intense, suspicious scrutiny of the proprietor.

Waking with these memories, I finally allowed myself to believe we were about to meet. I set off for the encounter with the girl I knew I loved, like a teenager on his first date.

Remarkably, perhaps, it was only now that a significant conundrum pertaining to our situation occurred to me. Until now, I had it fixed in my mind: I was going to meet Cristina, and as Cristina, I longed for the day I would meet Danny.

But how could that be so?

I was Cristina yesterday, and today I was Danny. The Cristina I was to meet today at Trafalgar Square would be but a ghost, the shadow Cristina of alternate days when I was being Danny . . .

As I sat on the bus, my mind raced in ever more frantic circles, pursuing the logic of a situation that had no logic.

Who was I going to meet today? Would shadow-Cristina even know who I was?

I was early. It was a bright spring day and the tourists, and the pigeons, were out in force. I could not stand still in my nervous anticipation, so I walked around the square, eagerly looking out for the slight, gamin figure of Cristina Velásquez.

Eleven o’clock came and went, and Cristina did not arrive.

I checked my watch obsessively. Five past the hour, and still no sign of her. What might have happened? Had she been taken ill, or been struck down while crossing a road? Had her ghost-self forgotten, or not deemed this meeting important? I was beside myself with apprehension.

At noon she had still not appeared.

I did not know what to do. Where was she?

In the modern age, it is hard to recall the complications—and frustrations—of a time when communication was not instantaneous, taken for granted. In an age of social media and mobile phones, the idea that a missed rendezvous could seem so final is hard to fathom. But in the early 1960s, of course, there was no easy way to locate someone in such a situation.

In the end, in desperation, I found a telephone box and thumbed through the directory until I located the Earl’s Court hotel where I had booked in after my flight as Cristina the day before.

I dialled the number, impatiently waiting each time as the rotary dial spun slowly back to its resting position before I could dial the next digit.

“Traveller’s Rest, what can I do for you?”

It shouldn’t have surprised me that I recognised the voice of the man who had studied me from head to toe upon my arrival the day before. Of course I did: I had been there.

“Hello,” I said, my brain racing. “I’m trying to locate a guest of yours. We were supposed to meet this morning but she didn’t turn up. I’m concerned for her safety.”

I paused, but there was no response, a clear indication of how much the hotel proprietor cared about our failed rendezvous.

“Her name is Cristina Velásquez, and she flew in from Barcelona yesterday afternoon.” I had to consciously correct myself before speaking aloud: she flew in, not I.

“You got the wrong hotel, mate. There’s no Christine whatever staying here.”

“But there is! Cristina, not Christine. She checked in yesterday.” I did. I recalled it vividly.

“Listen, mate. Unless your Christine has a thick red beard and speaks like a Paddy, then you’ve got the wrong place. We’re full up with Irish navvies, just as we always are. Now good day to you.”

And, with that, the line went dead.

I hurried home, weeping at the irony: I was unable to communicate with the person to whom I was closest in all the world.

But tomorrow . . . Tomorrow I would wake up as Cristina, with not only my bitter memories of today, but with hers also. Then I would find out the reason for her non-appearance.

That night I went to bed early and, after a long time, sleep came.

• • • •

I awoke at dawn and blinked up at the cracked ceiling of the hotel room, and Cristina’s memories of the day before came crashing in on me.

I recalled the excitement of navigating London’s buses, with a knowledge of the network no young Catalan on her first visit to the country should have. Of peering out of the windows as the capital unfolded around me, familiar and yet seen for the first time.

I recalled the visceral thrill as I alighted from the bus at Trafalgar Square at five minutes to eleven and approached the designated stone lion where we were due to meet. My heart pumped heavily and my thoughts were feverish as I scanned the tourists in the square.

And then, with now terrible familiarity, I relived the growing disappointment as I realised that the tall, blond figure of Danny was not among them.

As I had as Danny, Cristina had waited hours, and still that blond young man she had seen in a mirror so many times did not show himself. Unlike Danny, she had no number to call: as Danny, I lodged in a Crouch End terraced house with no telephone. The only number she had was that of my parents in Barnes, but what good would that be?

• • • •

Early the following day, in desperation, I as Danny took a bus to the hotel in Earl’s Court where she was staying. Loitering across the street, I saw a succession of burly labourers emerge, but no Cristina.

The following morning, as Cristina, I woke up with the memory of visiting the hotel as Danny, and those of Cristina yet again going to Trafalgar Square at eleven.

In my desperation, I took a taxi to Crouch End, and hurried down the garden path. I lifted and dropped the lion’s head knocker and waited, my throat dry and my heart beating wildly.

An ancient, grey-haired woman opened the door and peered at me suspiciously, and when I asked if Danny was at home, the woman looked querulous. “Danny? Who’s Danny? There’s no one here called Danny.”

And when I as Cristina looked more closely at the front door, now closed firmly in my face, I realised that it was not the door I knew from memory: Danny’s front door was navy blue and freshly painted; this one was black and peeling.

• • • •

The following week, working on a terrible intuition, I as Danny booked a flight to Barcelona and rode a bus to El Carmel. Knowing full well the outcome, I climbed the steep street and approached the ugly square block where I as Cristina lived—so familiar from a thousand memories, and yet subtly different. I took the stairs to the third floor and rapped on the door of number eighteen.

A flustered mother with a babe in arms snatched open the door, listened to my gabbled question, and told me that no one called Cristina Velásquez lived there, or ever had.

In futile desperation, I tried the fourth floor, then the second, and so on, until I had exhausted all possibilities, but to no avail.

I even went to the gallery where I knew I as Cristina worked, only to be told that no one by that name was employed there.

At last, abject in defeat, and bemused, I took the next flight back to London.

• • • •

Years passed.

We became ever more melancholy and introverted, our relationships with others—both close and passing—doomed to fail because we were always holding something in reserve. We lived with the terrible knowledge of the irony of our situation: We experienced alternate lives, as one, as intimate as it was possible to be—and yet by some cruel trick of the universe, forever and impossibly parted.

We craved the other; as Danny, I desired to hold Cristina’s slim body to mine, and I as Cristina wanted no one but Danny.

Some say that what we love in our love object is no more than a reflection of ourselves—like two mirrors placed face to face and reflecting each other into an infinity of solipsism.

If that were so, then it was certainly true in our situation.

• • • •

Deprived of what we could not attain, and perhaps in a perverted desire to hurt that which we each desired, we embarked on a series of ill-fated and masochistic affairs with pale substitutes of each other. We might have had the other in mind, as it were, but in the flesh we were forever denied—so as Cristina I chased unsuitable, tall blond men, and I as Danny debased myself at the feet of slight, raven-haired beauties.

As Danny, I even married a petite French woman called Claudette, and for a time managed to convince myself that I had broken out of the vicious circle, but it only lasted eighteen months before Claudette had finally had enough of my prickly, standoffish manner. With delicious irony, the final straw was when I called Cristina’s name aloud while I was dreaming, only to awaken to Claudette’s accusations that I must be having an affair with this mysterious Cristina.

• • • •

At some point—I do not recall when, the late 1970s perhaps, a time when my divorce from Claudette was reaching pyrotechnic extremes, and in Barcelona I was finding the stresses of our peculiar double existence almost too much to bear—as Cristina I read an article in a Spanish science journal reporting the research of a Swiss quantum physicist. He claimed to have proved, mathematically, the existence of an alternative world, of another Earth existing in close contiguity with our own.

We were excited. Could this, we wondered, explain our unique condition? Did we exist, Cristina and Danny, side by side on different Earths, our flesh separated by the width of mere molecules that might as well have been a million miles apart, but our minds in some strange way conjoined?

Was that the explanation?

When I woke the next day as Danny, I wrote to the physicist, making good use of my fluency in French—perhaps the one good thing to come from my brief marriage to the fiery Claudette. I couched our experience in theoretical terms, but received no reply. I’m sure I came across as some kind of crank, but still the absence of response rankled and lingered for long weeks until I finally gave up hope of a reply.

We heard no more of the physicist’s claims, though we scanned all the journals and research papers relating to quantum physics until our minds whirled with a multitude of abstruse impossibilities.

• • • •

The internet came along when we were in our sixties, and entrenched in our ways. In our work in Barcelona and London, we used computers where required, but little beyond that.

One day I plucked up the courage to ask a young colleague in the Linguistics Department at UCL if he could help me find an old colleague by the name of Cristina Velásquez, an art historian I claimed to have met at a conference in Madrid. I could tell from the young man’s knowing smile he thought there was more to it than that, and I chose not to correct him or tell him more.

“You sure?” he said, after a few minutes spent tapping away on his laptop in the Starbucks where we had arranged to meet. He turned the screen to show me the fruits of his search. “I can’t find her, which is odd in itself. Everyone leaves some kind of digital footprint these days. There’s a Maria Velásquez at the University of Granada—a daughter, perhaps?” Maria Velásquez turned out to be not a day older than thirty. And Afro-Caribbean.

The next result was a Mexican artist, now resident in the USA. A set of Facebook profiles—so my young colleague told me—included a fiery redhead from Chile, a woman from Guatemala, and a pouting twenty-something woman who, from the thumbnail image I briefly glimpsed, appeared to be posing in her underwear.

“Maybe Cristina doesn’t use the internet,” I said tentatively.

My colleague laughed at the very idea, then paused, eyeing me more closely, no doubt reminding himself that the reason he was helping me was that there were still a few people, at least, of my generation who had little interest in the internet and social media.

And it was true: What use did the world of computers offer me in my futile quest? My experience of asking my friend to search for Cristina online merely reminded me of that failed rendezvous at Trafalgar Square in the early 1960s: faster and slicker a search, and no doubt more comprehensive, but just as doomed to failure.

The years continued to pass, and eventually the attraction of the flesh paled until all that remained was the Cristina- and Danny-shaped holes in our existence, a quest that had formed who we were so thoroughly that without it we would have been entirely different people.

We became reclusive, entire unto ourselves and yet on some fundamental level unfulfilled. Increasingly, we thought, what was happening to us was not so much inexplicable as something with no basis in objective reality and therefore resistant to logical explanation. What we experienced was no more than a sick, subjective malaise.

• • • •

In time, we retired and bought cottages on the coastlines of our respective countries, Cristina on the rugged littoral north of Barcelona, Danny beside a quiet Devon estuary.

We dreamed away our old age, wondering what might have been had we not been blessed by our double lives . . . or cursed.

And then, one day in high summer, it happened.

• • • •

As Danny, I pottered around the garden, then prepared myself a simple evening meal and sat in the conservatory with a glass of port, watching the sun set. I looked forward to the morning, when I as Cristina would, as habit decreed, rise early and make my slow way to the local market. We enjoyed market days in rural Catalonia.

A little drunk, I fell into a deep sleep, and awoke the following morning as myself . . . I mean, as Danny.

I experienced a kind of existential panic.

Had I become so drunk the night before that I had slept through an entire day and night? But I had had only two glasses of port the previous evening, and anyway today was the third of July, as it should be.

As it should be . . . I should have been experiencing the life of an elderly, gray-haired—but still beautiful—Catalan woman called Cristina Velásquez. But instead I was locked in an aging arthritis-ridden, and distinctly male, body.

I missed her with all my being: I missed the reassurance of Cristina’s comforting reality.

Until this very point, I could never have imagined how powerfully I would feel that absence.

What had happened to my love?

• • • •

I went to sleep that night in anticipation, and awoke to bitter disappointment. And so the following night and morning, and the next and the next . . .

At last I came to understand that I was left with that enjoyed by every other human being: a single, consecutive life.

And loneliness beyond endurance.

• • • •

And so now I must reconcile myself.

She is gone. Whether Cristina Velásquez was another aspect of me who lived a parallel life on another Earth, or a figment of a young boy’s war-damaged personality, or something else entirely, that existence has reached its inevitable conclusion.

Cristina Velásquez is no more. As Cristina, I had not been aware of any creeping illness, so I can only assume it came suddenly, a heart attack or a tragic accident.

Today I even had the foolish idea of searching one more time, inputting my other name into Google—yes, I have finally caught up with modernity, to an extent—but found nothing. No accident, no report of a death of Cristina Velásquez. Of course there was nothing.

I did not need that, in any case. The changed nature of my existence was evidence enough.

And so I pour myself a glass of Cristina’s favourite Empordà rosé rather than my usual port, and take it out to the conservatory.

Across the estuary, the sun is setting, lighting the sky a fiery red.

My friends—such as they have ever been—have always treated me with a somewhat pitying attitude for the isolated and apparently lonely existence I have led, but how could I ever convince them that I have—I realise now—lived a life less lonely than any of them?

For I have never been alone in the world, not for a moment.

And so I raise my glass and drink to you, Cristina.

To us.

And to a life lived doubly to the full.

Salut, amor meu!

Until I wake as you again.