Spring has sprung early this year. April showers by March, May flowers by April, fake tan by May. For the first time in eight years Dave is single. With the detachment of one not yet fully inducted into an alien group, he observes how its paid-up members celebrate the opening of the mating season:

1) eat low fat
2) work out twice a week
3) keep that mobile charged

Only on the telecommunications front is he making any progress, Dave thinks. He digs into his pocket and pulls out his curvy new phone. For weeks after she left, whenever the house phone rang the message would play back in her singsong voice: ‘David and Rachel are out, so talk to us now or, try us later.’ He didn’t know how to edit the message, so he got rid of both machine and line. It just felt like the right way to go.

His new phone is the double of Captain Kirk’s old powder compact ‘communicator’. Dave pages through to his voicemail and a feminized call-waiting style voice says, You have NO messages.

He snaps the phone shut hoping the person next to him has not heard, but she is busy reading a free paper, seemingly undisturbed by the noise from the road works. Outside, a woman in house slippers shuffles by in slow motion while the bus rocks gently on the spot.

He remembers how Rachel hated this commute: it’s one of the reasons she wanted to move. Irritated with himself for having a Rachel thought, he clicks through the names on his phone book. This doesn’t take long and is deeply uninspiring, so he stuffs the phone back in his pocket. The person he really ought to call, Dave decides, is the woman he met at that gallery. But her number is not saved to memory. That was before he bought this mobile, before the split.

In fact it was the weekend before the split, but at the time he wasn’t to know. All he knew was, Rachel and the other designers from Milk had gone kayaking. Or white-water rafting, he wasn’t sure which; some high-risk extreme sport that involved getting wet, anyway. They were welcome to it. In Rachel’s absence he moped happily. Without the list of social and domestic chores she normally compiled, the weekend passed deliciously slowly.

She hadn’t even set up any viewings for him to do. Flat viewings had featured big on Rachel’s lists this year. A new year’s resolution thing, as far as he could tell.

‘We need to move,’ she’d announced one day in mid-January.

‘Do we?’

‘Come on, Dave!’

‘But you like it here.’

‘I used to, like, a million years ago. We were students then. We’re grown up now, we need our own place.’

‘This is our place.’

‘Think of the future.’

Dave spent a great deal of time thinking of the future, as it happened. How could you not, if you worked in stem cell research?

When he was little Dave believed everything he saw on the TV sci-fi shows. He thought he’d beam his way up to other planets as soon as he was old enough – probably when he was about ten and a half. He was still waiting. But at least he was waiting actively. Now that his thirtieth birthday was looming, his work felt particularly urgent. Dave was hoping for a breakthrough soon – say by the time he was 35; he didn’t want to spend his last two or three centuries in a failing, decrepit body. In the future he believed in, he told Rachel: ‘Where you live will be less of an issue; the big questions will be, how long can you live for, and in what kind of body?’

‘That’s rich coming from you, considering you point blank refuse to go to the gym,’ Rachel said. She just didn’t twig that it was function, not form, that motivated him.

So far, though, major breakthroughs in the field have been thin on the ground. Ethics have held things back ever since the Seventies. Look at how fast communications developed over the same period. Still, if they’d got that far with phones and computers, he thought, maybe they’d get there in the end with immortality, intergalactic travel and all the other Space Age must-haves still on the wish list.

Had Seventies technology not been so primeval, it’s the decade Dave would have most liked to live in. He was born in 1979, so he didn’t know it first-hand. But based on the clothes, films, art and wallpaper, it seems to him the period from 1965 to the mid-Seventies was the best and the most future-pointing decade so far. Even the primitive tech had had its moments – they shipped people to the moon and back inside tinpot spaceships made out of milk bottle tops collected on Blue Peter. How cool was that?

Not very cool at all, Dave. You loser. You want to spend the rest of your life stuck in Camberwell, don’t you?

It was Rachel’s voice. It couldn’t be, she was off in Devon playing extreme sports, but it sounded like her. Mixed with that call-waiting voice.

Dave opened the fridge. Empty, apart from a few jars that had been there a long time.

Your turn to shop, Dave, the voice said. And do buy something healthy for a change.

This was bad. It was like he’d been fitted with some sort of Rachel remote control; she’d left him with no chores, yet here he was making them up. Ignoring the voice, he chose to live dangerously. He took a bus uptown, then trawled along Tin Pan Alley. Feeling rain on his face, he stumbled inside the nearest shop.

Steam rose from valleys teeming with lush rainforest, clouds curled around mountains peaks and reverse-evaporated into mountain streams, then teetered back into an effervescent, oceanic river. Dave felt like he’d entered a life-size video game. He was in a luminous 2D world, and yet it felt more real than anything he’d seen all week. Some printed stickers revealed that the river was the Mekong, the pictures were by a young Lao photographer, and he was actually in a photographic gallery. Laos didn’t feature on Rachel’s top five travel destinations, it wasn’t even on her long-list of approved countries, yet instantly Dave craved to go there.

In an area that doubled as a café he found more riverscapes. Stepping back to view an ultra-wide panorama, he bumped into a woman. Elbow into breast – that delicate give was unmistakable. Turning to apologise, he saw a petite and gorgeous woman whose Juliet Binoche eyes glinted at him from behind glasses with thick black frames.

For a second they stared at each other like gormless actors in an indie film, but instead of taking an art-directed walk in the rain they both laughed.

‘Sorry.’

‘S’okay.’ She shrugged.

‘Coffee?’

‘Tea. Thanks.’

Those few words chased away the illusion: she was not French but Scottish, and unlike Juliette Binoche she didn’t use controlled osmosis to melt sugar lumps in her coffee. She didn’t even drink coffee, she drank tea with no sugar. Her dreamy gaze focused on the mountains behind him, and he struggled for a few words to bridge the gap.

‘Makes you want to pack up and leave, doesn’t it?’

‘Aye, catch yourself a slow boat to Luang Prabang.’ Her eyes briefly caught his. ‘Tough coming home after, but, I’d say.’

Talk drifted to other things. Things Dave doesn’t remember now; the long, easy sort of chat that old college friends have. Later, he feels certain meeting her would have been the start of something, but for two key details. One, Rachel had neglected to tell him about her and Thing. And two, that man showed up. That curly-haired man who cheek-kissed her with lazy confidence and nodded casually at him. Dave somehow found this more irritating than if he’d been ignored entirely.

He stood, and claimed to be running late.

The Scottish woman smiled and gave him a postcard.

Outside, it was still raining.

He ducked under an awning and looked at the card. In the picture, an orange-robed boy monk extended a bare foot into a gap between speed-blurred tuk-tuks, motorbikes and bicycles. Dave agonised over what came next: the orange-robed boy was frozen on the cusp of an action that might as easily end in death as life.

He flipped the card over. A name, scrawled in capitals: EAVAN. And, yes, a mobile number.

The seconds sped up.

Dave felt sick.

To him, this was a ticket to the unknown. The chance to live a little, like single people did. Maybe even have an affair.

Trembling, he slipped the card between the pages of a book from the gallery shop. The bus home took forever, as usual. By the time Dave's stop came, everything was running at normal speed once more, right down to the woman in slippers shuffling slowly along the road in a neck-and-neck race with the bus. Dave obediently trundled round the supermarket on the way home; still oblivious, still neutered, still part of a long-term relationship.

Two days after she got back, Rachel set aside ten whole minutes to break the news to him. Actually, she hadn’t been in Devon kayaking or white-water rafting with her team. She’d spent the weekend in London. With someone else. No, it wasn't anybody he knew. Call him Thing. His name didn’t matter; what mattered was, she and Thing had decided to move in together. In fact, she said, ‘We’ve placed a deposit on a rent-to-buy apartment in Battersea.’

Dave said nothing.

‘I’m sorry,’ she said.

What could he say? He couldn’t argue with that ‘we’.

It was as if she’d already left. Boom. Eight years together, over. Rachel belonged in the new place now, with Thing. He could picture it clearly. Like the apartments she had made him view, it would have hardwood floors, stainless steel appliances and a bathroom with power shower.

Here in the old place, by contrast, he would live alone in a rented flat that had one of London’s last remaining avocado baths. Stuck in Camberwell, as she would say.

A taxi arrived. Rachel left, taking one large suitcase with her.

Soon, a courier arrived with signed authority to remove her things. It was all done in less than an hour. He had to hand it to her: once she made up her mind, Rachel didn’t hang about.

That first week or two, while the answerphone was being economical with the truth, Dave fantasized about storming into Milk’s airy Shoreditch studio to, what was it, ‘name and shame’ Rachel. Or did she need to be a celebrity for that? He felt dizzy. He wasn’t sleeping well. At night, the auto-Rachel voice woke him up. It had stopped giving orders now. Instead, the voice said helpful things like, I do hope you get your life back in gear, David. I don't like to see you in this state. It made him want to smash windows.

Luckily, before Dave got anywhere with naming and shaming he remembered that, thanks to him, the lab now used Milk to do its visual design, so a scene at her work was not a good plan.

He needed a decontamination policy.

At work, this was not difficult to engineer: he found a talented young East German designer fresh out of art school who was desperate for a commission. Design budgets were always tight, so the cost differential alone would have carried it, but this guy was seriously good. A few mock-ups changed hands and the matter was settled. The words ‘Rachel from Milk’ were never mentioned again.

Home required greater effort.

The courier had taken only the items on Rachel's list: many others remained. Useful things like a potato peeler, a radio, the bathroom mat. But if he wanted to decontaminate, he must do it consistently. Removal, neutralisation, detoxification. Photographic evidence was first to go, followed by any book, CD, DVD, or computer game that was hers. Reluctantly, he even sent on the amp and speakers she’d said he could look after. (Thing, apparently, had a Bang & Olufsen.)

Total decontamination has taken weeks to achieve. Last night Dave tipped the final items in a British Heart Foundation skip. He’s been hoping that, with the clutter gone, his flat will look the way it did when he first moved in: a perfect Seventies time capsule. But despite the space liberated, the place seems to have shrunk. Worse, the previous tenant’s hessian wall-covering is frayed and Dave doesn’t know where to buy any fresh. For all he knows, hessian has been banned by Health and Safety. So on the weekend, after his trip to the bookshops, he swings by the gallery. For maximum coverage he buys outsize posters and pins them over the hessian.

All that greenery, mist clinging to the mountains, the silvered ribbons of sheer waterfalls. Like walking into a myth. For the rest of the weekend he barely leaves the room. He sleeps right there on the sofa, getting a solid eight hours for the first time in over a month. Decontamination is working.

It is around this time that Dave remembers the woman he met at the gallery. What was her name again? Looks like Juliette Binoche, sounds like Kirsty Wark. It seems ridiculous as they’ve only met once, but he even starts to wonder what it would be like to live with her. Eventually her name comes to him. Eavan. But how to find her?

He spends days looking for the postcard she gave him. The metal sheet and magnets they once used as a notice board vanished weeks ago. Perhaps the card went the same way. The flat’s so bare it doesn’t take long to confirm it’s missing.

He’s let Eavan down, Dave tells himself. For all he knows she’s stuck seeing that twit with the fluffy hair. She must be new to London; that would be why she puts up with him.

On Saturday Dave skips his trek to the bookshops and sifts through his recycle bin. Junk mail keeps coming from estate agents – an unfunny sequel to his and Rachel’s abortive effort to buy a flat. Sometimes he reads the property descriptions. He knows exactly which ones she’d have wanted to view: the ‘stunning’ maisonettes in conservation areas, not the ‘unique’, or ‘unusual’ studios that are in fact converted garages.

He finds one postcard. From the new gym at the Elephant, asking him to an open day. He lets it tumble back in the bin.

Monday morning he’s crosschecking stats on rodent longevity in an effort to replicate a result from a partner lab in Italy. He’s halfway through and so far there’s not the faintest whiff of correlation. Each lab used identical doses of the same batch of chemical, but as far as he can tell, although it may induce longer life in Italian rats, it doesn’t make a blind bit of difference to British ones. That’s ruling out externals, though. Maybe some lab technician over in Italy is playing opera music on the nightshift, and it isn’t factored in. The rats could be living longer because they’re having a better time.

On his lunch break, Dave has an idea. It only takes a few minutes browsing online to look into it. A quick look at his flexi-loan says it’s doable. He doesn’t think things over too much in case there's a contraindication, he just presses ‘OK’, and goes back to his half-eaten sandwich.

That evening, unsure which vaccines he needs, he reaches for the guidebook on the half-empty bookshelf. A postcard flutters out and lands face up: a photo of a barefoot child monk on a busy street in Luang Prabang. Dave snatches the card and turns it over. Old rain has teased grey drips out of the bold marker pen scrawl, but it’s still legible.

Dave thinks carefully before calling Eavan.

He almost doesn’t call her at all. He’s looking at the bikes and tuk-tuks, trying to imagine what happened three seconds after this photo was taken. Hearing a screech of metal. Or did they slow down in time? He can't know. Too many competing visions of what comes next, and no reliable way to test them.

There are times, Dave tells himself as he keys the number into the phone, when careful is not what you need.

‘Hullo?’

‘Good evening, Eavan. Congratulations, you’re the winner of our Adventure of a Lifetime prize. A holiday to Laos.’

‘I, what? Is this some kind of joke?’

The phone exaggerates her accent.

‘No joke. An expenses-paid holiday to Laos, to be taken in the next three months.’

‘Me? A holiday for two?’

‘No, just yourself. Non-transferable.’

‘Bit of a relief to be honest. No one to bring at the minute.’

She laughs. It’s hard to believe a woman like this is single. She sounds intelligent, down-to-earth, sexy.

‘Can I ask you something?’

‘Anything.’ He keeps his tone neutral, aiming for call-centre cool.

‘Thing is, I cannot remember entering this competition. Will they be wanting proof of entry?’

‘Uh, no. It’s ah… a private sponsorship, connected with, uh, a photographic gallery.’

‘Right.’

‘I believe entrants left their business cards in the café.’

‘I have no business card.’

All along he’s emulated a machine; now he worries his tone will slip. Can’t she just say yes? Take the money and run?

‘Actually, it is more like a postcard, which I suppose raises the question as to whether your entry was advantaged size-wise. But if you’re not interested, I assure you we have other candidates.’

He hangs up hurriedly, sweating.

Has she guessed it's him? If she has, she must think him some kind of freak. That’s it, he can forget about Eavan. And he needs to change tack if he’s to stand a chance in future with anyone else. He needs to apply a bit of science, instead of just pitching in with no prep, hoping to luck out in some random, amateur way.

Another glossy postcard has arrived offering a free trial at the gym. Dave’s ready to bin it, but he stops himself. If a toned physique impresses a significant proportion of women, well, why not? Since when does it hurt to have statistics on your side? He calls the number, only the wait time is too long, so he selects the call-back option.

Fifteen minutes later, the phone rings.

‘I caved eventually,’ he says. ‘I rang to ask about your special offer.’

‘What? What offer?’

‘Is that the gym –’

A yelp of laughter. ‘Got it. I remember you now.’

‘I–Eavan?’

‘We met at the gallery, didn’t we? Photos of the Mekong.’

‘Yes. My name’s Dave. Sorry, I hope you don’t think –’

A pause, then, ‘No, it’s fine. I'm afraid I’ll have to pass on your prize, Dave.’

The way she’s talking now though, it’s different. He can tell she’s smiling, and he can’t help smiling back.

‘Very kind, but I cannot accept. Still, bit of a coincidence this, but I’m planning my own trip to Asia, so if we’re over at the same time, I’m on for meeting up, if you are.’