FICTION:TIM WOKE THAT morning amidst the décor of another family's Christmas. Paul, his cousin and the owner of the house, had decamped with his wife Rasa and their two-year-old to some frozen village in the Latvian interior to spend the holidays with his wife's people, writes MOLLY MCCLOSKEY

That was how Paul had put it, my wife’s people, as though he were making good on some ancient promise. Tim pictured them in voluminous hooded robes, walking sticks of crooked branch, the child slack-jawed in a sling, as his parents trudged the snow-covered plain until a squat cabin hove into view.

Your people shall be my people . . .

It was 2008. Tim had flown into Dublin the night before. Bujumbura-Nairobi-Amsterdam-London-Dublin. He’d hardly minded that it took forever. He had often felt in the no-place of airports – nexus of so many lives, actual and possible – an elevation of his spirit, moments of weightlessness, when he realized anew that the world was vast enough to vanish into.

No one but Paul and Rasa knew he was in Ireland – not his widowed father in Rathfarnham, not his sisters or their families, not either of the two friends from college with whom he maintained sporadic contact. There was no hurry, he was planning to stay for a while. He would go to his father in a few days.

He’d left the tree lights on the night before, and when he came down the stairs Christmas morning – the sitting room empty, his stockinged feet soundless on the floorboards, the lights blinking incessant patterns through the gloom like some code he had to crack – he felt like the last man on earth.

He made coffee and stood at the front window, which overlooked the canal. Nothing moved. There was not a person on the street. A thin fog smudged the view. The willows looked stricken. And rising from the primordial ooze of the canal were two broken branches and the algaed half-trapezoid of a shopping trolley, all breaking the surface at skewed angles. The canal and its banks had the look of a misty bayou, a look of stunned aftermath, as though civilization had been here and gone.

His cousin had told him he’d phone from Latvia on the day, and Tim had said, “Don’t. Please.”

THE PREVIOUS CHRISTMAS: a warm overcast day on an island off the coast of Kenya, a teary conversation in an open-air cafe, being accused of all the wrong things. It wasn’t that there was nothing to accuse him of, it was that she, Anna, kept missing the mark, so that he began to feel the urge to help her, to coax her closer to the truth, as though they were teammates in a game of charades.

They had met four years earlier on the east coast of Sri Lanka, in a room festooned with artificial limbs. She was a protection officer working with Tamils and was at the medical centre having tea with a doctor friend of hers. Tim had only just arrived in the country; Anna was leaving in a month. Half a year later, he followed her to northern Uganda. A year there, and they went together to southern Sudan, then to Kampala, and finally, to Burundi.

She had seen a lot, much more, much worse, than he had. He was an engineer, managing water and sanitation projects; she moved into resettlement. Day after day interviewing refugees, trying to sort the true stories from the concoctions, gauging whether the truth was bad enough to warrant furthering a person’s resettlement application. It was a perverse kind of competition people were forced to engage in, and she said that almost immediately your idea of what was endurable became warped; so much got relativised, measured against what she’d heard already that day, that week, that year.

Sometimes he felt like a child in front of her.

They’d spent their first Christmas together on that same island where four years later they’d begun to unravel. Even as they’d wept in the cafe – yes, he’d cried too, a childish smeary snuffling, quite unbeautiful compared to her silken tears – he’d still loved her, desperately.

But the centre was gone, he could no longer tell where, if anywhere, the feeling emanated from. It floated, without anchor, and she had wanted to build a life on something that was as shifting and unsolid as silt. Or maybe he was wrong, maybe he didn’t love her desperately but was simply confusing desperation with love. He had no idea. The facts he could grasp had dwindled to the barest: that potable water was always a good thing, that he should never drive anywhere without a spare. Anything big-picture, long-term, in any way ambiguous, dizzied him with its conflicting claims. He turned the questions on her, midnight conversations, wired, as though grinding her for an exam in Grand Abstractions.

“In a world without suffering,” he would ask, “what would the expression of humanity look like? If we were all perfectly content beings, could there be such a thing as sacrifice? If no one needed anything, how could anyone perform an act of generosity?”

She understood the questions, she just didn’t see the point of them. The world he was positing was beyond hypothetical. “Anyway, you can’t say that someone is both human and impervious to the acts of others. Those are mutually exclusive states.”

“But just say,” he would persist, “just say –”

And she would cut him off. “For God’s sake, I have to get up in the morning.”

There were days he looked around him and all he could see was need, pressing from all sides, each person transmitting to him an urgent message of need: a look, a word, an upturned palm.

The day Anna got on the plane to go back to Montreal, he knew he would leave, too. He had just been offered a job in Nairobi, as a water and sanitation policy analyst for east Africa. Everyone assumed he’d take it. In fact, he felt flat with apathy. He had, he knew, reached the point in his career where his dealings would be almost exclusively with other high-ranking bureaucrats. Soon, having done his time in the field, he would be given a post in Geneva or New York, and the circle would be complete.

When he turned it down, when he said he thought he might leave altogether, people said: “You mean leave leave? But what will you do?” However chaotic the worlds in which they moved, there was an apparent, counterbalancing order – the hierarchies strictly defined; the deprivations precise, the sites of indulgence clearly mapped, the faces recurring and familiar; each city, zone, autonomous region stamped with a number purporting to quantify its dangers – and they believed that beyond the borders of all these crises lay a world of vagueness and uncertainty in which he could only take his chances.

TIM HAD NEVER in his life spent a Christmas day alone, and he hadn’t spent a Christmas in Dublin for 15 years. He had left the city a few months after finishing his degree. His mother had died during his final year at university, at the age of 53, five months and 21 days after her diagnosis. In her absence, the already strained relationship with his father grew quickly brittle. Tim was too young then, and too blind with his own grief, to make allowances for his father’s behaviour, and had heard in the things he’d said not the ravings of an agonized mind, but merely all the criticisms that had been silenced while Tim’s mother was alive. When Tim announced that he was leaving, his father accused him of desertion. As though he were a spouse or a soldier.

After lunch, he walked towards the city, along the canal, down Grand Parade. Rust-coloured reeds as tall as he was rose along the banks. The black water ran like a tunnel through the fog. He went as far as Percy Place, then crossed the humped bridge and skirted round the church that was planted in the middle of the street as though set down there from on high. The street bulged either side of it like a snake who’d just eaten.

The fog had thickened slightly; it was the colour of ash and cold to the skin. He walked slowly, as though moving through a billowy afterlife. He imagined himself in the wake of a freak disaster, one that had left structures intact but swept living things from the earth.

Three or four cars rolled past but otherwise he saw no one until he was the far side of Merrion Square. Then, a couple, a young family, a middle-aged man walking a small white dog. He turned up Grafton Street, where perhaps a dozen people strolled in the quiet. Everyone walked slowly, as he did, and because there were so few of them about, they took note of each other, glances of shy curiosity, infinitely gentle, as though they could not quite believe this world they were living in.

He went down to the quays, then turned back towards home. Passing through Merrion Square, he saw two feet sticking up the far side of a shrub. His throat tightened as he stepped closer. The man was only sleeping. He might’ve been 40, or he might’ve been 25. He had the sunken face of an addict. Tim thought of gathering him up and taking him home, and imagined the house swept clean of valuables by morning. His mother’s older sister had met her future husband when he was sleeping rough under a bridge in Canada. It was 1957. They were both immigrants. She’d brought him home and propped him up in front of a fire and within months he’d passed his test to become a bus driver, and for the rest of his life was a devoted husband and an upstanding citizen. He had a beautiful singing voice and he used to sing while she played the piano, and they were ordinary, good people who loved each other through many a long winter.

Tim was worried the gates would close and the man would freeze. He had seen a patrol car parked outside the square; he went out and it was still there, and he told one of the guards about the sleeping man.

The guard told him not to worry. “We always do the rounds.”

Tim knew that in his life he had walked right past many such men. Yet he told the guards not because it was Christmas, but because there were so few people left – so few survivors – that each one of them seemed precious and necessary.

BY THE TIME he’d reached the canal again, dusk was leaching into the fog, and the air had gone a steely grey. The streetlights were furry globes. He looked at the trees along the opposite bank, different kinds he couldn’t name, all bare and black-branched, and he thought that he preferred them like this, stripped down to their own severe beauty.

He had slowed to the point where he was no longer walking. Movement seemed, he hardly knew to what, a disruption. He thought of his uncle, in the hour just before his future wife appeared under the bridge. If his uncle had been granted a wish, he would not have dared to think so big as what in fact was given to him.

He looks at the sheen on the water, the opaqueness overhead. Worlds recede, all the chatter; there is only a lull, like the space between breaths. See him standing on the bank, inhabiting his life as though it were an unfamiliar neighbourhood he’d wandered into. He knows nothing. He doesn’t know that this time next year, he will walk the tundra of Phoenix Park with a woman whose existence he is now unaware of. He doesn’t know that the nation will freeze over, that all the talk those weeks will be of salt, as though they’ve been pitched back centuries, a million mineral traders jabbering in the marketplace. He doesn’t know that in spring, his father will have a terrible fall, that he, Tim, will be the one to find him, and that on that day the most tentative easing of tensions will begin. He doesn’t know that his sister will give birth, that there will be a small fire in the house where he is now staying but that no one will be hurt. He doesn’t know that, later still, one New Year’s day, Anna will phone him from her office in Kinshasa, that in the sound of her voice he will hear whole worlds.

He knows, of course, that everything is changing, all the time, new moments arriving, one after another, but like most people, he can hardly, deep down, believe it. Like most people, he is mired in the now in the least consoling sense.

He is walking again. It is almost dark. By tomorrow, this ashen fog will have lifted and another weather will be upon him, and then another and another, until the warmth seeps back into the earth and the days stretch to breaking point, and these hours have vanished as surely as if they’d never happened.

Molly McCloskey's new book, Circles Around the Sun, a memoir about her brother's schizophrenia, will be published by Penguin Ireland in June