"...How can you cross almost any river by foot? Banks in most towns close at five p.m. so past that time it's easy to walk across dry. There's also the exception of bank holidays when you can cross throughout the day..." – Adapted from a word-play riddle.

It started as it too often does with ducks though no-one, not even the ducks themselves, could have anticipated how unlucky they'd been, and how much good they might've done had they waddled a few feet further in the greening reeds of the Serpentine. Morning dawned as they bobbed amongst the silvery waves and each might have quacked a severe warning to two approaching joggers if those joggers had taken the time to learn the nuances of British mallard dialect, and, of course, had the ducks been omnipotent. Sadly neither were true. Two aquatic individuals followed the joggers along the lakeside, kept pace with the dusty horse track, and stared at the one falling behind.

The park was two halves, cleaved down the middle from north to south by a thick two-lane road that roared with cars from gate to gate. It was huge, and a circuit of just one of the halves would leave a novice gasping amongst the oaks. Passing the gate you'd see its lion and its unicorn gazing serenely down, each peeling to rust, each quietly looking on day by day. Be careful, they'd seem to say. We know this place. This place is ours to guard and to hold. We've been here since the Exhibition. And you tell me: where's the Crystal palace now? The Northern unicorn would seem to glare at you from the half-way point of your run at the northern gate, waiting for a slip-up. And the Southern statues, one of the joggers liked to think, would see a job well done.

The jogger's name was Matt and he'd managed up 'till now. From his halls of residence on Exhibition road he'd followed his friend and passed the embassies lining the street with their cotton-weave flags. He'd entered beneath the lion and the unicorn of the southern gate into Hyde Park and taken the perimeter route around the lake. He'd rounded Diana's memorial fine but now the sprint was taking its toll. There was good reason to run as fast as you could down Exhibition road. The street was more a well-manicured death-trap than a cakewalk. Danger of death for pedestrians barely describes the road layout. You could call it a cakewalk, but only if your metaphorical cake was a mess of black and white criss-crossing cobblestones from which no-one, pedestrian or driver or holy man could tell where the road ended and the pavement began.

In essence the paving stones of Exhibition road itself were Art.

The kind of art that hung on a wall upside down would not only inconvenience travellers but also maintain the same dangerous statement that twelve tonnes of baked goods truck and man ought to meet one another intimately.

Now after the sprint he couldn't keep up. They were almost rounding the eastern edge of the park. The other jogger was Scott. It was Scott's idea to do jogs, and Scott's idea had slowly ground him down as the evening runs had turned to early afternoon runs. Then they'd slowly turned to morning runs, then longer morning runs. They were runs which left him struggling to climb the stairs without shaking.

He looked to the ducks, then gave them the finger when they quacked at him. He thought about it a bit more and gave Scott the finger behind his back too. The eastern bridge was coming up and the edge of the Serpentine seemed to shake with each step. He called for a break in this brutal regime.

"Hey," he struggled. "Look. It's the bridge. Feed the ducks?"

They slowed as their feet swapped from the dense sand to the reassuring comfort of a granite bridge which ironically bordered but did not actually bridge the Serpentine properly at all. Like much of the frivolity in central London this logically makes no sense except when seen in person.

"These morning runs are going to be the end of me, you know," he tried to say doubled over.

His friend couldn't make out the rasping whisper, but replied with a thoughtful "mhm" anyway. Matt struggled, leaned on the balustrade, found that his pain whilst bent-over was worse than standing straight. Distract yourself, keep the pain at bay. Ducks. Ducks would help. The tired jogger reached into a pocket and pulled out a handful of oats which, on second thought, had been a poor choice even if he was grateful to the waterfowl. The sesame was the worst and he struggled to shake it out - it had all mixed with the lint, which counted as bad for his jacket pocket and simultaneously surprisingly palatable for the buoyant recipients. Someone less in tune with Matt's thoughts might have considered his reference to ducks as something of an obsession. He knew the current fixation was more from tiredness than anything else. A generous handful of oat mix was thrown to the helpless birds. They seemed temporarily placated. Scott was asking him something.

"What's that?" he whispered.

"You do realize you need to, like, pace yourself to a decent speed," said Scott.

Matt waved him away.

"I can't run with a cross between, I dunno, a steam engine and a beatboxer," he continued. "I mean it's soothing to me in a masochistic way, a bit like new-age CD's with the whale noises for going to sleep. But I'm starting to get to the stage where I'm thinking 'come on, Moby Dick, just end it all.' You know?" Scott lined up his photo of a faultless skyline across the bridge. No doubt it would end up unrecognisably filtered online.

"So, in this scenario, you're going to harpoon me if I'm not careful," said Matt.

"Exactly."

"Would it be a slow death?"

"Probably."

"Worse than this?"

Scott ignored him.

The balustrade of the pretend-bridge had helped after all to ease the stitches a bit. Weak quacks came from below and Matt used what the little energy he had to shake remaining oat mix out of his pockets and throw it in the general direction. He hadn't expected it to be this warm, the run up the Serpentine was colder. He made sure to store that piece of information in his repository intended specifically to fill desperate awkward silences, somewhere on the scale of conversation topics between 'dull' and 'painful', maybe not for Scott but some poor unsuspecting soul somewhere later in the day. He couldn't settle on which category fit better and the useless fact oscillated uncertainly within his mind. His friend fumbled to return his phone to the holstered sleeve of his jogging shirt. It's all a part of the struggles of amateur photography.

It was in Matt's opinion quite easy to pick out his mate from a crowd. Scott was a good foot shorter than the average doorframe, reasonably well-built and a true aficionado of short-sleeved shirts. Such a description seemed dangerously close to vanity, but Scott didn't have the characteristic swagger nor dark shades needed to lie in those upper echelons of daily gym-goers taking serious care of themselves in thick italics. The short-sleeves and shorts were the same all year round, and a mystery for winter London weather. Scott's wardrobe just didn't believe January existed. He himself reckoned jumpers were mandatory until at least mid-March. Matt was not interested in short-sleeved shirts nor weightlifting, running or cycling. Nor would he have hit his head on a doorframe, as the average door would typically exceed his five foot seven and two-eights of an inch or, in Satan's measurement, just shy of a metre and three-quarters, all hail the dark lord. All in all, the take home message is not to trust Matt's opinion. You'd find Scott in the club by the bar half an hour after you'd lost him six songs ago because everyone's wearing a white t-shirt.

"By Beelzebub's horns, are you done strapping that thing to your arm?" Matt fancied something dramatic.

"What are you on about M? My phone? Yep, I'm done. Got a great snap of the river here. Even managed to get your pals in frame."

"No, not pals. The ducks are not my pals. They're just in it for oats."

"I got both of them with the posh Weetabix floating away in the water and all. Beautiful."

"You overestimate how much they care about us. You should've heard them earlier Scott. Such profane, angry quacks." This was astonishingly accurate.

"I guess. Yeah, they do kind of look angry."

Scott had meandered to the other end of the bridge and now stood expectantly even as Matt couldn't help but wish he just had a few more minutes. Just a bit longer. Let me stay. Let me just stay and watch the Serpentine, and the willows and the waves. He put one foot on a grating and inadvertently solving the small mystery that had bothered him. The grating was venting heat, near to scalding.

"Hey Scott?"

"Mhm. Yes Matthew? You ready to feel the burn?

"No. Come here for a sec."

"It'll get easier M, the more you do it."

"It's not gotten any less painful so far."

"It will," Scott insisted. He relented, and joined Matt at the grate.

"These are usually pretty standard, not shoe-melting, right?"

"What's that?" He touched it tentatively. "Crap that's hot."

"Maybe it's like that New York thing where they vent heat from the subway."

"Come on, M, let's go. We're on a timer here. It could be like that thing Foster-Hall told us."

"Biomed guy?"

"Yeah."

"The one who went on the charity tour of the tunnels?"

"University maintenance guys told him they go as far as Exhibition road and beyond, under Chemistry, Bio, the Sherfield building. It makes sense the heat's got to escape somewhere. Come on."

Matt struggled and his joints ached as he ground them into motion. The charity tour of the tunnels were stopped, he remembered someone say. There was barely enough interest that year. But as he upped the pace he thought to himself that was a shame. Because it'd be interesting to see how the university worked behind the scenes, and see it from another angle underground (and see the urban legends for myself). That last part he added quietly. Because it gave him the same feeling that the unicorn seemed to give him. Tread carefully, or don't tread at all. There was the run north and back westward along the lakeside to look forward to. And Matt wondered what state he'd be in when he saw the northern unicorn. Thankfully there was another bridge back crossing the Serpentine. And more ducks to feed.

Matt turned off the bridge and onto a sandy horse track. Scott hated horses. As for any passionate cyclist the hatred for horses comes as part of the package alongside a borderline fetishistic obsession with Lycra. Matt made sure they came into contact with as many horses as humanely possible on each run. Every little bit helped to tire out the athlete. He listened to complaints about how they ruined his tires when he followed horses, or problems passing them on an inside lane. He'd let Scott talk, and let him run out of breath. And maybe then he'd make it to the Northern unicorn gate in one piece.

***

"...how likely is this style of catastrophe? The answer seems to be 'almost nil' no matter which world you're in across the central plane of the multiverse. The rogue elements needed are random, rare and subject to transient existence that is typically harmless. Nevertheless I think everyone here would rather put emphasis on the 'almost'..." – excerpt from a lecture by T. Kitamura, twelfth annual British Chaos and Divergence conference.

Paul Raynes, was having a trademarked rough morning. It was a rough morning that other well-established hard guys like him could have, and could drink alone at the bar for it without being judged. He could knock back a double whiskey and ask for another in a few seconds. That's what the ones who didn't last long did, as far as he knew. The way the transatlantic flight entertainment seemed to show it tough guys usually ended up dying firing a heavy machine gun, biceps exposed, at whatever massive conflict they had to deal with. He'd flicked through the rest of the films on the flight, and hadn't settled on any of them. Fuck it. He'd had a bad morning, a bad year, hell maybe a bad decade. There wasn't a point in worrying too much about it.

Raynes had lost count of how many transatlantic flights he'd done. His job was banal – take this suitcase with its data to whatever place it was needed. He rarely knew what it was he was carrying or why he was never treated to first class. Travelling business was good enough for him to sleep. Arrivals so far at Heathrow had been a minor nightmare. He pulled out his passport with one slender hand in the queue through border security and went through in his mind again who he was pretending to be today for the sake of practice. Diplomatic and economic advisor to the British government, he read. He looked the part, and the image was complete with one of those diplomatic passports that opened doors you hadn't known were there and maybe ended up feeling sleazy. The bald eagle stared back at him from its blue cover. Inside, the pale pages of Mount Rushmore were coated in stamps from New York, the Statue of Liberty donned one on her chest from London while overleaf the entirety of a Mississippi steamer was covered by a furious-looking Russian visa.

He closed it and munched on a mint imperial. It resisted, but soon he overcame the struggle to reach its core. Raynes was the sort of man that would punch your lights out before you'd even known there were lights installed and fully operational, and would follow that by blowing out the fuse box for good measure. Once he'd finished he'd set the fuse box on fire. That was probably, in fact, what the protocol called for to the letter. Orders didn't mean they couldn't have his input and consent. Imagining stuff like that brightened his day and seemed fun. And if the reality of violence wasn't fun at least he could pretend it was relieving some kind of unknown tension in his life. 'Relieving stress' was apparently a good catch-all reason for doing anything. Even if it wasn't true that it relieved stress he'd be damned if he didn't pretend.

Psychiatrists were avoided with a sharpened barge pole. Mints were preferred cold and fresh, his beer colder if it were possible. He knew that his most likely threat in the airport immigration line was a man standing twelve deep behind, the nearest exit was through a staff door on his left and he could easily beat armed police to their submachine guns at less than three beastly metres. His eyes gently slid off a couple in front he suspected were smuggling a Something Yet to be Determined and restlessly fell to the Heathrow border guard. She waved him forward and smiled. People were always smiling at him.

"Good morning." Jeanne had just finished a cup of tea and was ready for a good day's work. Maybe she'd catch some discrepancies and earn herself employee of the month. She could hope. Raynes handed over the passport. She looked up at him, back to the photo and scanned it eagle-side down. Somehow he was paler in person.

"What's your purpose of visit?"

"Diplomatic advisor," he said. It reminded her of a slowed voice behind hospice doors. Jeanne grasped to hold onto her good morning vibe but her eyes glazed and sank. It was gone so fast she wondered if it was really there in the first place. The landing card was checked. In grim reality she slowly stamped both. Accidentally hitting backspace she had to take a moment to re-enter the data and wasted more time. The passport returned to Raynes. She tried one last time.

"Have a nice morning Mr. Owen. Welcome to the UK." The greeting hung there briefly and collapsed to the floor.

Jeanne wondered whether that counted as assaulting staff. She felt in her heart it really ought to. The man, meanwhile, ignored her and gazed toward the clock behind the desk, then continued on. His phone buzzed so he read and replied while ignoring baggage reclaim. He avoided the groups milling in loose gangs around the suitcases rotating into view and did his best to skirt round ambling ankle-crush trolleys. He replied that he'd arrived, and confirmed the meeting with British intelligence was at the usual place. Raynes relented, agreed with himself that yes, he felt a bit bad for ignoring the immigration border girl and that yes, maybe, for once, he'd make a conscious effort to take the afternoon off and relax. Maybe airport misery could stay at the airport.

It's best now to note that Heathrow is distinct in two significant ways from other international counterparts. First of all its newest questionable international terminal suffers from the brand of architecture that suggests stripping off the ceiling to leave the wiring bare is a good idea. While it does look modern, it also makes many people uncomfortable if they notice how few screws hold up the pesky eighty kilo ventilation units, and many an electrical engineer has gone red in the face at their exposed cable management. There were petitions for the words 'no, really, we promise madam, the terminal was finished two years ago' to be played on loop over the speakers. That would, however, bring more attention to where and how the speakers are mounted and cause more panic. Altogether the engineers at Heathrow decided to wash their hands of the affair with the result being a number of them were promptly electrocuted. Raynes didn't think this a great shame.

Secondly the airport, along with others around London, has an inevitable butterfly effect on its arrivals. The classic example is that if a butterfly flaps its wings the effect, however small, on the atmosphere might be enough to change the course of events to cause a tornado somewhere down the line, months later. A minor annoyance for a Swiss businessman by a baggage trolley running over a shoe at the fresh start of his journey might spoil the mood for longer than anyone could realise and the whole thing could escalate, days later, to manifest in two head chefs fired and a catastrophic hedge fund decision. The greatest of these damages to morale, a Queen Alexandra's birdwing of a butterfly effect (with wingspan of half a foot) comes from none other than searching for your humble private-hire taxi driver.

Private hire drivers are the first impression any tourist will get of the country, and therefore make life very difficult if that tourist doesn't like hide and seek. Almost all hold white scavenger placards with a name. By a stroke of genius these are misspelled, assuming a passive-aggressive slouch behind a Times newspaper isn't enough to go by. You can walk the length of the terminal not finding your driver, only to go back to where you were in the first place to watch them step out of the depths of oblivion after half an hour's search. To top it off as part of the experience your driver may or may not obscure their handwriting. This is merely personal preference, and is part of the art form.

Raynes was greeted with such a sight as he passed out of customs. Nothing to declare was a personal motto he lived by. He glanced at the mass of Bluetooth headsets angling around every ear amongst lanyards of a whole host of companies. Eyes that could aim to kill at three hundred devilish metres couldn't spot his pseudonym. Eventually he squinted and noticed a card for a "Mr. Owyn" by a coffee shop and made his way. An hour and a half later he was dropped off by Charing Cross Road and spent the next forty-five minutes casually buying mints and checking for anyone following. A little while later he walked through the familiar double doors of a bookstore behemoth and headed to its tiny café on the fifth floor where you can get away with reading a copy and not paying for it. It was in most respects a good meeting place for the exchange. They were playing jazz though. He hated jazz. Raynes ordered a cappuccino from a barista who suddenly stopped smiling and then picked up a random travel book from a nearby bookshelf while he waited.

'Nine-hundred and ninety nine places to see before you die.' He realized too late his diplomatic cover with the business-like attire and suitcase probably called for something with more graphs in it, or at least a yachting brochure. He was almost certain he'd never see more than fifty of these 'must-see' places. The past twelve he'd flicked through were in countries searching for someone matching his description. Raynes took a sip and glanced either side in search of his contact who seemed, thankfully, even later than him, and grimaced when the coffee made an unholy alliance with constant fresh breath. He finished his scan and went back to studying the great Australian outback while a saxophone in the corner screamed its dying soloist's melancholy. Two trumpets joined and soon a drummer had got in on the action as well. He managed to get through most of Eastern Europe, a small slice of Italy, part of the Middle-East and was perusing the marvels of Petra when he glimpsed the man he'd been waiting for.

A thin lawn of a greying hair bounded its way up the stairs. Colourful cashmere followed and draped over a bulging frame. Topping it all off was a behemoth of a three-quarters raincoat. The usual man it was then. The slab figure glanced towards Raynes, gave a wave, and then glided his way clumsily past tables to order. Raynes' contact thought he deserved an espresso after five flights of stairs and took with it a full pack of wafer biscuits. The barista's face lit up once more. She wondered why other customers had to be so miserable and went back to absently refilling the machine with two pints of semi-skimmed. Tiny espresso acquired the man breezed back towards Raynes like a cruise liner through a quiche stall and sighed as he deposited the tiny coffee, scraped a chair and sat opposite. The man began fiddling with one pocket and looked distressed. The American agent tried to start. His contact from British secret service didn't look up.

"Um, good morning Schofield. What's new with, uh," Raynes was transfixed as his counterpart rustled about in all available coat pockets. "What's new with you? You good?" The huge man was red with frustration.

Patrick Schofield of the MI5 gave a triumphant smile as the biscuits made a deep thwack on the table, tilting it back and forth. Espresso wobbled dangerously. Raynes was sure they'd be all crumbs now. A second solo, this time from a poorly-muffled trumpet, was about to begin.

"Sorry Mr. Raynes. We can begin. It's been hectic but it's good to see you." Schofield folded a piece of paper to put under the table to stop it wobbling, and saw that Raynes had the suitcase. "Please, help yourself to biscuits." He ducked down beneath the table to try and jam the piece of paper under a table leg.

"You got it?" Raynes tried to wobble the table, found it was better.

"I think so." Schofield emerged from underneath. "Are you alright?" wheezed the Englishman. He remembered something. "Oh, it's jazz. I see."

Raynes wasn't ever sure whether he liked this attitude. The strained screech of the trumpet he didn't care for at all. It was altogether weird to have a man like Schofield in MI5. He sometimes seemed so normal in that horrifically British way that came across as eccentric anywhere else. Why did British secret service have to be so gratingly carefree? Schofield ripped open the biscuits ambitiously in its midsection and took one. He offered one to Raynes, who shrugged and took two. Schofield wasn't above eating with his mouth open. Chocolate crumbs flew and hit cashmere. It had happened before.

"So," slammed thick hands on the table "what have you got for me today?" asked Schofield. He broke a fourth biscuit into minute pieces and dipped them carefully in espresso. The man was on a casual diet that restricted roast potatoes. Raynes stared in amazement. He always did when he was with Schofield.

"I've got what's under the table. That's all."

"Only one wheeled suitcase? Without oversize baggage they're not getting their money's worth on you."

"We've gone digital. It's all hard-drives now. What you're suggesting is upending an IBM server. It's just not needed."

Schofield purred. "Mmm okay. Well, perfect." Schofield was right. It was perfect.

You'd never give the man a second glance on the street. It would be no surprise if you'd assumed he'd taken half a day off work to watch his childrens' sports day and gone shopping for birthday presents on Oxford Street. He'd stop to compliment particularly cute-looking dogs who wagged oblivious to the shockingly high-calibre revolver in his inner pocket. 'Oh, he's a Highland terrier, adorable. Who's adorable? Yes you are.' Not a second glance would be given at his innocent face by the security team on the thirty-fourth floor of a reputable bank. Finding a dead stock broker in the toilet and the intruder gone was met with a sense by security that they'd somehow been beaten, or that the broker had committed suicide, but no-one was really sure how. Schofield smiled and hungrily munched on the corner of another biscuit. And, unlike Raynes, Schofield loved the chaos of a good jazz piece.

"D'you reckon I should save some of these for later?" he half-heartedly closed the packet. "Emily hates it when she finds out I've been at the carbs. To me," he looked down "I think it's really made no difference". Emily was Schofield's wife. Whether she actually existed was bothering Raynes for quite some time. He really hoped so. The alternative wasn't good. Schofield had pictures, worn ones, but none with him in it.

"I reckon she knows best for you".

"Too true." Schofield's phone buzzed. "Hold on, I've just got to write a text. It's the Ukrainians this week, and stockbrokers causing trouble. They won't give up." Half of the packet was gone. The espresso resolutely remained. He thought it was always good to catch up with his favourite American. The coffee was reasonable and the tables just rickety enough to annoy everyone involved. He sent off his text and showed Raynes a large A4 colouring book for kids, the kind with stickers at the back which always seem to be the first to go missing while the rest of the book lingers black and white. This one was supercars. The stickers would probably disappear and reappear glued upside-down on low-hanging furniture while the rest of the book might end up furiously scribbled over some time later, the result being that every picture looks like a supercar chased by a ball of yarn. Schofield saw it as stills from the Indiana-Jones-esque spin off that nobody wanted.

"Sorry about that. Thought I'd get Jamie something nice. He's gone through those felt-tip pens you got him bloody fast. Bad for the walls, but he loves the colours."

Raynes took a gulp of cappuccino and apologized for his second-hand role in Schofield's upcoming redecoration. They chatted shop for a bit and settled down to rationing the last few biscuits after all.

After another five minutes Schofield was about to say the words 'well I better get going. See you soon, Paul'. The espresso was finished. Raynes cursed that he'd only taken four biscuits. They were likewise gone. Had events played out only fractionally differently Patrick Schofield would have taken the wheeled suitcase and rolled it in full view clanking down the stairs before waving a goodbye. Raynes would've returned to the embassy, then back on a plane. They might have parted ways with the CIA agent feeling he'd once again failed to crack this ripe enigma of a man. Sadly for them, perhaps, none of that happened. Instead Schofield got a call on his third phone, a clunky black Nokia with a dire number reserved for emergencies greater than his standard emergency second phone, itself of much greater importance than his day primary work phone. He let out a surprised cough, this being different to his standard cigarette chokes. His counterpart gripped the aged electronics through a multitude of crumbs.

"Hello?" A pause. Schofield put up a finger in apology and turned away from Raynes. The other merely shrugged and took a final drag or two of cappuccino while looking for an ambush. Satisfied, he turned to his phone and pretended to text while trying to listen in. He cursed. A wailing tuba made it impossible. Schofield seemed to nod. He'd gone red and was writing something on a napkin. Raynes didn't like the sound of this. He gently put his hand on his pistol while brushing some crumbs with another. It was small, ceramic, untraceable, and would cause incalculable damage to British-American relations. That was the pistol. Crumbs only do incalculable damage to friendships with those allergic to wheat, or café cleaning staff. Under different circumstances Raynes might have even taken the safety off, or pointed it at someone.

"Yes. Right. Sure." Another group of whispered murmurs followed. "It would be my pleasure. Of course. Would you like a word?" Schofield glanced at Raynes seemingly disappointed. "One of these days I worry the table will wobble and you'll fire that. Here, they want to talk to you."

Raynes didn't move an inch, or a satanistic centimetre for that matter. The Nokia remained in Schofield's outstretched arm. He relaxed.

"Yeah. Sure." He took the little phone. "Hello?"

"This is Raynes, yes?" It was a female voice, low, business-like, the sort of voice that might cold-call you to ask about insurance. Schofield mouthed her name but he didn't catch it.

"Yes."

"I have spoken to a Ms. Navari at the U.S Embassy who told me that you've known Patrick for a long while, now," she said. "We were hoping you might aid in investigating a terror threat, foster co-operation between the agencies, or something of that sort. Would you be interested?"

"For Navari? Yeah, of course." Raynes remembered she'd been promoted, but that was a while back. She'd been on maternity leave for about a year, hadn't she?

"Thank you. It should only be an hour, maybe two."

"Not a problem." He was lying. This was rather a problem. Calls out of the blue don't just happen, and certainly not from people who didn't normally have authority over you. The woman seemed genuinely apologetic. He frowned at Schofield. "Specifically, what's this about?" he asked, but didn't get a real answer. At that moment Raynes felt an unmistakeable buzzing in his pocket. Flashbacks of notorious stories beat around his mind, of people being fixed to disappear. Not CIA though, and certainly not here. Not in the bookstore. This was fine. Raynes said his goodbyes, hung up with one hand and picked up with another to speak to his own people, who said the same, plus a little more. He wondered if he'd ever come close to being fixed to disappear. Soon both he and Schofield left. 'Nine-hundred and ninety nine places to see before you die' was gone too.