"We're at a park," said the lanky young man, pointing out the obvious. "This feels right to you?"

"Yep," John Watson replied to his friend. "This ... this is it."

Bill Murray grinned broadly at him. "Soak up the feeling mate; it'll be a long while before you're back here again."

They wandered down a thin concrete pathway, stopping every few metres for John to ensure they were headed in the right direction. Locating your Soul's Home – the place that irritating internal urge was constantly demanding you go to – was the antithesis of navigation in the Army. No compass, no gps, no calculations, this was just following the natural call of every cell in your damn body shrieking get your arse there immediately. It was, John thought, possibly how migratory birds felt come autumn.

"How the hell are we going to survive deployment," John muttered, "with this frigging craving? It's not going to shut up the moment I leave this patch of South London. I don't give a shit what our training said; that bit's going to be bloody rubbish."

"Well, once we find your Soul's Home, we can stay as long as you want. Provided you're not one of those 'sacred place of reverence and worship' type nutters," Bill said.

John smiled. "I'll be fine, really. Just venting. Still a bit irritated we miss the next Great Lustrum."

"How many have you been to?"

"Three – first one when I was seventeen, then all the rest since. You?"

"Same. Still no luck though."

John's instincts took them off the path and across a slightly ill maintained patch of grass. "They're pretty elusive, those Potentials. Maybe ours are war veterans, and they're already in Afghanistan."

"I thought you thought yours was a doctor? Or a nurse?" Bill smirked as they reached a gravel path. John flushed slightly.

"For the past decade my Soul's Home has been St Barts. A chemistry lab, if you have to know. What else was I to assume? And now it's moved to some god forsaken park. I mean what the hell am I meant to work out from that?"

"Mine was a once at a Tesco."

John snorted. "Which aisle?"

"Tea. Oh, shut it!"

And John did – his laugh cut quite short as they reached a dark stone fountain. Circular and deep, water trickled in sluggish lumps down its centre piece; an unimaginative stack of basins. John stared at it, slowly reaching to touch its base. His manu meridiem caused the granite to gleam orange yellow before John was clutching it tightly.

"I'm here." He whispered. "This fountain. It's my Soul's Home."

Bill gazed in wonderment at this place that had so much significance to his best friend, and said in an awed voice, "It's covered in bird shit."

John splashed him.

It was the best part of ten years before John's hand broke the stillness of the fountain's water again. It was slightly ridiculous how early he'd shown up – his watch read quarter past ten, and he'd already been sitting here for three goddamn hours. Really, it was quite cold, waiting by the fountain. Its dark stone had captured the frostiness from the light snowfall and seemed determined to inject every last bit of it into his arse. Who the bloody hell decided to make the Great Lustrum fall on the last day of January?

Very few of the park's dwellers had been deterred by the sun's enjoyable but unspectacular setting, and it remained unusually busy. But then again, this wasn't an average day. This blasted, still covered in bird shit fountain probably held the same significance to a lot of the people hanging around as it did to John. Waiting anxiously for midnight.

Well, significant to enough people that some poor young girl was stuck at the entrance handing out fliers for some company probably paying her 50p an hour. The only people employable on this day were the ones whose manu meridiem hadn't started shining yet.

John pulled the scrunched flier out of his back pocket, flexing it towards to pale street lights. His breath tumbled as vapour as he folded it out to read it properly. He needed to distract himself from the trepidation that had been building for weeks now. Army honed senses were over analysing every person milling around. He'd probably be insane by the time midnight managed to happen.

Right, reading. Distraction.

ARE YOU READY TO MEET YOUR POTENTIAL? The headline screamed at him. Everything you need to know about Colour Significance and Lumen Manifestation!

Ugh. Colour significance? John almost gave up on the gaudy pink flier then. The whole match-making take had been gaining a lot of popularity recently. Never mind the fact that your Potential could have any role in your life – most commonly they were a mentor, a friend or a colleague.

People – and no doubt companies like 'Lumen-ificance', the flier's distibuter – were attaching all sorts of stupid words like 'soul mate' and 'wing share'. Psychoanalysing the colour of your manu meridiem was obvious. If your palm happened to glow red, then it was practically a given you'd end up shagging your Potential. It was worse than Valentine's Day.

This ridiculous flier had managed to take it one step further. According to it, your palm wasn't glowing 'red' – no, was it ruby or garnet? How pretentious.

And what does that mean for your future with your Potential? Rubies have long been associated with beauty and nobility. A deep ruby colour indicates you have a knack for wisdom in decision making, and who can forget the romantic undertones ...

This pamphlet was made of gossip. John couldn't understand how people actually believed this tripe.

Opalescent is the rarest of all manu meridiem, and is characterised by its natural variety of hues, capable of expressing every colour in the visible spectrum. When lumen is sparked, it is said the different colours swirl like fire. It is revered above all others.

White meridiem are classified into two groups: diamonds and pearls. The former is said to be the original form that manu meridiem took when our bioluminescence first evolved, and is therefore the most pure. It is a very clear light. It indicates innocence, but also great promise. The latter is more easily visible, with a cloudy pearl sheen. If this is you, you are blessed with dignity and tranquillity.

For all his ideals of resolutely not giving a toss about this brand of pseudo-science, it was surprisingly engaging. Like comparing all of the horoscopes to see which one contained the most nonsense.

Emerald meridiems have been long admired, especially in the wake of Queen Victoria I, whose brilliant green she shared with Prince Albert was famous throughout the empire. It has strong associations with healing and truth seeking.

So which bloody gemstone was he supposed to be?

Topaz. Yellow meridiems have a strong sense of fun about them. Potentials with this colour can be assured a deep friendship will develop...

Nope. He'd reached his bullshit threshold for one day. The pamphlet went back into the pocket and out came the phone. Twenty past ten. This was agonising. John's heart quickened against instruction as two more people entered the park.

Any one of these people around me – any of them! Could be my Potential. I could be looking at them right now! John's frenzied mind insisted.

Ella had specifically warned him against this. He really had to calm down and keep his hopes in perspective. His Potential didn't have a great track record with showing up to Great Lustrums.

Great Lustrums been invented to allow the population to meet their Potentials, with a public holiday every five years so you could journey to your shared Soul's Home and find your prospective partner. He'd even gotten a bonus in his army pension specifically for it, to cover travel costs. With the explosion in industry productivity that occurred in the aftermath of each Great Lustrum it was in the government's interest to make sure as many Potentials met as possible.

Society taught you there were two things you needed. A romantic partner; and your Potential. Sometimes they were the same person. John had neither.

John clacked his cane against the pebbles underfoot. In a way it was enjoyable to sit here, and have the urge finally sated. The craving that had gnawed at him for long hours in the Afghani desert, changed into satisfaction – he was almost happy, for the first time in months. It was like a rubber band that had been pulled perpetually taut and only now was it relaxed. Though the park held memories of Bill, and Bill was still in Afghanistan. And terribly missed.

Twenty-two past ten. The space-time continuum had been displaced. That was the only explanation for the crawling minutes.

When waiting for long hours during the war John had practiced reciting Afghani numbers. There didn't seem much point to that now.

Twenty-two and a half past ten.

Anything would be better than this agony. Even the flier. John flattened out its abused paper.

The double spread had a feature on lumen manifestation. Besides the whole colour thing, there was the spectacular lightshow that occurred when two matching manu meridiem touched for the first time, known as lumen. The normal soft light that developed during puberty would explode outwards and curl around its owners. The flier helpfully provided horrendously medically inaccurate illustrations of the various levels of manifestation that could occur. Did people seriously think that little comets of light would spin around them?

In actuality the lumen's shape was very reminiscent of a magnetic field. John had seen it quite a few times at his previous Great Lustrums. One had been rather small, barely extending past that pair's arms, but another had been quite a sight, reaching beyond their bodies to encase them in a loose cage of lime green lumen.

It was only in textbooks that John had seen the largest of the lumen – when it extended back beyond the person, like at the poles of a magnetic field. Bursting from their shoulder blades, it was likened to a wing structure – hence the pet name from the Valentine's Day industry. The stupid flier had depicted it as some form of angel wings. Complete with feathers. John sneered at the drawing in disgust.

When things became weird, and no matter what anyone said, the whole Potential business was tinged with weird, John stuck to the facts. Your Potential was the one who would reveal to you – well, your true potential. The one who, often in some form of partnership, worked best with you. And vice versa. Whether the largest, wing form of lumen signified a particularly powerful compatibility between two people hadn't been scientifically proven... but everyone knew about Lennon and McCartney's white lumen manifestation.

John stuffed the annoying flier back into his pocket. Whether his hand was trembling from the cold, or post-traumatic stress disorder, he couldn't quite tell.

Ella said it was post-traumatic stress disorder. But he was a doctor too, and he knew that if it was, stressful situations were supposed to make it worse. Not heal it.

Maybe that's what his Potential would be; someone who stressed him out so much the intermittent tremor would fix itself and he could return to surgery. God, he needed to stop imagining things like that. But when meeting them would transform his life, and hopefully release him from the pathetic shell of an existence he was stuck in ... it was hard not to.

That was such an unhealthy thought. It wasn't up to someone else to fix his life for him; he had to do that on his own. His Potential didn't owe him anything; was under no obligation to even talk to him after they met. But since being delivered home ... just ... nothing happened to him. And he was exhausted.

Annoyed at himself, John wrenched himself up from the cool stone; perhaps a walk would clear his mind. The snow had moved on now, but freezing air bit at his exposed skin and made this shoulder and leg ache.

Who'd want him as their bloody Potential anyway? Oooh, a traumatised, depressed and invalided ex soldier? Freaking Christmas for no one. Some sort of government rehabilitation scientist, maybe.

As he mulled this over, John clacked down the thin concrete path snaking through the trees. Away from the street lights, and only a thin moon hanging in the sky, it was quite dark. Usually he'd point his left palm down and let his soft yellow manu meridiem light up the path – not quite an option tonight.

It was unspoken, but everyone knew the glove rule.

He was pretty sure the phone Harry had given him had a torch somewhere, but damned if he knew how to use that thing. Darkness it was, then.

If his Potential didn't show up tonight, maybe ... he'd try and get a job at a clinic. Maybe get a flat share? You can't afford London on an army pension, and John was loathe to live anywhere else.

Half ten! John limped passed a teenager sitting tensely on a bench, chewing her lip to pieces and clutching her right hand. Her first Great Lustrum. Maybe not everyone knew about the glove rule after all – a mauve manu meridiem was lighting her face softly.

Perhaps she just didn't care. John shared the sentiment; if it wasn't for the frigid temperature he'd have done away with them hours ago. After Afghanistan it seemed petty and trite.

Okay, he could appreciate the showmanship of everyone whipping off the gloves when the clock hands hit 12, finding their manu meridiem's colour on another person and finally locking hands with their Potential – but a big part of him just wanted it over.

Two people who could only be her parents stood nearby, holding hands. They were matching Potentials, sharing a deep velvet blue that glowed on their respective dominant hands. Thin tendrils of lumen were peeling off their palms; it never quite goes away after the first meeting. John gazed at it wistfully before heading back vaguely in the fountain's direction.

Impatience for midnight was clearly a feature in the park's occupant's minds. John could see two manu meridiem gleaming in the darkness – a rich, forest green and a dusky orange.

The dusky orange-! The thought struck John with enough force to freeze him in his tracks.

Harry. That was Harry's colour!

No.

No, her's was paler.

I think.

John's gloved hands flew to his phone.

[Outgoing text to: Harry Watson. 22:34]
Are you doing the GL tonight?

[Incoming text from: Harry Watson. 22.36]
Yes. At my Soul Home. You?

[Outgoing text to: Harry Watson. 22.36]
Same. Where would that be?

[Incoming text from: Harry Watson. 22.37]
Near the London Eye. Little bakery. Why?

[Outgoing text to: Harry Watson. 22.39]
Never mind. Good luck tonight.

[Incoming text from: Harry Watson. 22.40]
You thought you saw someone with my meridiem colour, didn't you? Don't forget, mine's the one whose glow is piss weak.

[Outgoing text to: Harry Watson. 22.42]
Harry, I've explained this so many times. The wattage of your manu meridiem is not an indicator of anything.

[Incoming text from: Harry Watson. 22.42]
Wish you'd explain that to society.

John sighed resignedly and slid his phone away. Any communication with Harry was an ordeal, and with the entire country highly strung on nerves tonight it'd only go downhill from here. He sat back down next to the fountain, leaning against its smooth stone edges and letting it act as a wind break.

His stupid glove was itching, though probably because he was paying so much attention to it. There was still a bit over an hour to go until midnight, but hell. People were starting early anyway – a few more pinpricks of coloured light speckled the park.

John gently eased the wool off his fingers, the welcoming beams of his manu meridiem gleaming in the darkness. He scratched out the itch luxuriously, so focused on his task that when the gravel in front of him crunched loudly John started.

He quickly closed his hand into a fist, shutting out most the strong golden light.

A tall, dark haired man with a long coat, and scarf whipping in the frigid wind stood before him. The park's lighting silhouetted his features, but not the tightly gloved hand extended towards John.

John found himself standing very suddenly. He began to return the handshake but the man shook his head impatiently and gently grasped John's rigid fist instead. John allowed the man to turn it over, palm side up, and uncurl his fingers.

Golden yellow light bathed both their faces, abolishing the darkness that made them anonymous, and John saw fiercely intelligent eyes scrutinise his manu meridiem and his own face in turn. John was finding it hard to swallow, and his heart was somewhere around his throat, beating like a madman.

The man released John, and without any hesitation gracefully extracted his own hand from its leather covering.

And John knew how it felt to see his golden light dancing in a palm that was not his own.