The Locust Theorem

science fiction story

It is probably best if we start with your body. I’d like you to touch yourself – on the arm, the face – somewhere where your hand can make contact with your skin. Feel it. Soft. Malleable. Our bodies are fantastically adaptable – fantastically adaptable – to external conditions. Well now, let’s think about that for a minute. Let’s think about external conditions. Where do external conditions start?’

A drop of sweat runs down my back under my shirt, from hairline to elasticated briefs. Bellbirds croon in the jacaranda trees outside. Thirty-seven degrees and the air conditioner’s broken. The lecture hall steams softly with our collective heat. Under my hand, my arm perspires, dampening my notes.

‘Anderson!’ My body snaps straight when Doctor Evans picks me out. Her rimless spectacles fix on my face. ‘Where do external conditions start?’

‘Um. Outside of me?’ Clueless again. Several of my classmates titter but Evans only smiles a little.

‘Alright. Let’s turn the question on its head. Where do you start?’

‘My skin?’

‘Your skin is crawling with hundreds of thousands of bacteria. You think they’re a part of you?’

Everyone laughs this time, even Su. Her eyes catch mine and she shakes her head. Not giving me the answers, then.

‘Gross. No.’

‘That’s a problem. Your stomach, colon and intestines are all crammed with bacteria too, aren’t they a part of you?’

‘Nah, they’re connected to your mouth and your arse, Doctor Evans. That’s like a hole running through the middle of you.’

‘Ok. So you are a body, with a hole of external conditions running through the middle.’ The class hoots, but she holds up a hand. ‘I can accept that. What about your secretions?’

‘My… secretions?’

‘Your secretions, Anderson. Tell me, for example, when does your urine stop being a part of you? Is it as it hits the toilet bowl, as it touches the air, or – like the bacteria – is it never really a part of you because it came from the outside when you drank?’

‘Probably the last one?’

Evans stops smiling and I can tell there’s a problem with what I’ve just said. Next to me, Su’s donned a dawning expression. As usual, she gets it way before I do. ‘You do know your body is about sixty- to sixty-five-per-cent water though, right? Are you saying everything you drink is technically external?’


‘What about what you eat?’

‘I guess it would follow that what I ate wouldn’t be a part of me either. Yeah.’

‘So what you eat and what you drink – the stuff that goes into making and growing your body – is not really a part of your body. What about air?’

‘Air definitely comes from the outside.’

‘So you are saying the oxygen in your blood stream is external- Ah! Wait! We got rid of the blood with the water, and the veins with the food, and the stomach and the skin and- Oh gosh, look at that, Anderson. You’ve classed your whole body as external.’

My jaw slackens and I move a sweat-slicked hand to my face. How can Su and Doctor Evans think in this heat? My brain wants to drop out of my ears, but Evans isn’t done with me yet. She shouts over the bell and the slack rustle of students packing up.

‘Thing is if you don’t start with your body, Anderson, where do you start?’

That heat. Those lectures. Like it was yesterday. Honestly, I didn’t care where I started, I just wanted a cold drink and a big spliff pronto.

Not long after that class, I switched my specialization, from genetic ethics to genetically modified crops. Doctor Evans gave me a sad look, like I was a stray. ‘Alright, if you think that’s for the best. I understand.’

I was co-opted into a study group where the main topic of conversation was how much wheat yield we could achieve per year. The only problem that visited my over-saturated brain after that was the population of earth and how to feed it. It didn’t make me content per se, but at least my head didn’t implode every time I opened a textbook. Su stayed on with Evans, but then her mind always was more pliant than mine. I liked facts and numbers, while Su drank in unproved theory and scientific relativism.

Su was always destined to discover something. We used to call her our resident genius. The nickname made her kick her book-bag into our shins, but even she couldn’t deny it. She was intimidatingly quick. She’d knit her brows for a moment, then she’d get something – a concept it took any lecturer hours to explain to the rest of us – and it would be stuck fast in her head, there to recall any time she needed.

If she hadn’t been so kind, she’d probably have been labelled as ‘a bit cerebral’ and ostracized, but as it was everybody loved her. She remembered friends’ birthdays, Skyped her mum and two younger sisters religiously once a week, thanked the lecturers and sent them interesting articles. She even had time for me. In fact, she and Doctor Evans were the only people who didn’t completely give up on me at university.

When Su left for a fully-funded MSc in Geneva, I was still retaking second year. ‘Look after yourself, hey Andy? And stop smoking so much green. It’s bad for your brain!’

The humiliation of Su overtaking me even though I was a full year older than her, followed by her subsequent silence, was one of the catalysts for me pulling my shit together. To everyone’s surprise, most of all my own, I managed to graduate with pretty good marks in the end, and my crop-yield buddies were so proud that they squeezed me into their funding application for a grant to investigate a new strain of heat-resistant barley. The project fed into a part-time MSc in Perth, with a meagre maintenance in exchange for teaching.

During that time, rumour reached me that Su had returned to Sydney, freshly decked with a shiny Harvard PhD and a newly-released book.

The book, Coherence, was marketed as popular science but it was dense stuff. My head needed half a bottle of whiskey before it was pliable enough to get to grips with Su’s ideas. Even then, I only got the theory abstractly, and I strongly suspected Doctor Evans had been one of the beta readers.

A new take on the old idea that if we are all interconnected, our planet is one organism, held apart from other beings only by the vacuum of space. A theory that could change the human story forever: if our legacy is the next generation, then what is the legacy of the Earth?

Partly out of friendship – and partly to prove I was clever enough to understand the damn thing – I wrote to Su telling her how insightful I thought Coherence was. She thanked me. And that was that.

Once my MSc was finished, I spent some months wallowing in the self-doubting miasma that so often seems to follow graduation, staring down a barrel of unemployment. So when I was offered a post at the National Ghanaian Unit for Agriculture, I didn’t think about it being on the other side of the world, I just jumped at it.

Droughts were not uncommon across the continent by that time. Climate change and regular extreme weather patterns like El Niño meant that every three-to-five years swathes of Central and Western Africa were deluged in dust and starvation. When I arrived, what would turn out to be one of the worst droughts in history was already getting underway to the north in Burkina Faso, and locusts had begun moving south in search of better grazing grounds.

Unable to contain the swarms, the government brought us in to work on a strain of crops that would be edible to humans but neutralise any locust feeders. We had tanks of the insects all over the labs, and for a while we mainly worked on ways of killing them. Even sanitized, it was not a fun job. As we turned up one dead end after another, we started to change tack.

Most people who’ve never lived around them don’t know that locusts start out life as grasshoppers. Normally grasshoppers are solitary creatures but, when drought hits, their feeding grounds become smaller, forcing them closer together. They form crowds and start bumping into one another. This regular contact raises their serotonin levels. Get those levels high enough and a switch flicks in the grasshoppers’ brain. They get smaller and change colour, metamorphosing until they become locusts. The transformation, known as locust polymorphism, is quick and difficult to reverse. Yet, by investing crops with certain hormonal features, that reverse-transformation was exactly what our team made its foolhardy goal.

Su arrived about six months after me. She wasn’t coming to see me, obviously. It was a research thing. We stayed in the same hotel and she even took a desk in our lab space, but for a couple of days after she landed, I kept missing her. As usual, I knew her by the other scientists’ awed whispers rather than an actual sighting. When we finally met, I was on a balcony three floors up and she was lying in the long grass behind the hotel, covered in grasshoppers.

‘Good way to get bitten by a snake, that.’

The grasshoppers scattered and she sat forward, throwing her hand up against the sun to get a better look at me. Her expression, at first cross, softened.

‘Andy Anderson, is that you?’ Her accent had shifted to some indefinable international-school lilt.

‘Been a while.’

‘It sure has.’

‘Fancy a drink?’

She checked her watch, the same Velcro Casio piece. ‘Why not.’

We went to the local watering hole, a place run by and populated with ex-pats, and exchanged stories. Gossiped about old friends, caught up on family news. Her mum had been killed in a car accident six months before.

‘It’s put a lot in perspective, obviously. I was weighing up a teaching post at Princeton, but I told them no.’

‘Seriously? You turned down Princeton?’ I thought of my own quest for a measly funded PhD and shrank internally. ‘Isn’t that the dream?’

‘I thought so. But. There’s just so much more to discover, y’know? I didn’t want to get tied down.’ She shrugged. ‘Anyway, what are you doing here…?’

Presently, some of the other folks from my lab turned up and coaxed us into dancing. We were all quite drunk. I walked Su back to her hotel room, which was right next to mine. She took a little bit too long to say goodnight but, all density, I didn’t pick up on the hint. We spent the next fortnight circling around each other gently, until one dawn we were both woken by the same howling coyote. I went out, throwing cheap hotel slippers off my balcony in the direction of the noise, and she nearly keeled over laughing. Leaning forwards over the slim, thirty-foot drop between our balconies, we held a whispered conversation then, reaching over the void between us, I kissed her.

I woke up the next morning, and every morning after that, in her bed. Su was exquisite, from the mind outwards. Being near her physically hurt – watching her fingers flick across a keyboard or the narrowing of her eyes as she concentrated – those quick, precise traits that were so utterly hers. I suggested we share a room more permanently. She took a loose thread from her red dress and tied it around my wrist. I told her I loved her. She said it back.

The first indication I had that something might be wrong was the day the builders came. They had set up scaffolding outside the hotel and, as Su was passing under it, one of them dropped a knife. It sailed four floors down, point-first, straight towards Su’s face. She looked up just in time for it to hit her. There was a sharp sound, like a blade against granite, before the knife fell to the ground and clattered away across the forecourt. Su was shaken but not hurt, aside from a light red irritation that bloomed in a line down her face.

The hotel manager was furious and the builders shuffled apologetically, but I was put on edge by the experience, which apparently no one else had seen. Under duress from Su, I tried to write it off as a happy freak accident, but even if I stopped talking about it, I couldn’t drop the incident. When we made love, I noticed how tough and tinny Su’s eyes had become. Over the next week, her skin grew hard and cold, as if in rigor mortis, but with a sense of the heat below the surface. When I asked her about it, she told me I was imaging things.

Then I caught her with her fist around the bar of the electric heater in her room. I cried out, snatched her hand back for her, held it close to my chest and inspected it for burns.

‘Nothing. There’s nothing there.’

‘I don’t know what you’re so worried about, I was just turning it on.’

I looked at the heater. ‘Come off it, that thing’s been on for hours.’

‘You’re imagining things.’

‘Stop it. Stop gaslighting me.’

‘I’m not gaslighting you.’

‘Tell me what’s going on then.’

‘I can’t.’

Our eyes locked. Hers defiant, mine confused.

‘Let it alone.’

‘I’m worried about you.’

‘You don’t need to be.’

That night I spooned her too tight and she clung back, her fingernails digging into my arm. Neither of us slept. Neither of us talked. I was fixated on what else I might have missed. Now I thought about it, when had I last seen Su eat anything? She drank water like a fish, but similarly I couldn’t remember her using the bathroom for a long time. I felt awful that it had taken me so long to notice, but they were such impossible shifts that, even once I saw them, my brain struggled to acknowledge them.

Telling other people about Su’s changes seemed like an idea that might get one or both of us committed, so I kept my mouth shut. When asked about her research, I just shrugged and said I was as in the dark as everyone else. It was almost true: I knew she was changing, but I didn’t know how or why it was happening. I didn’t even know who was funding her.

When you study how humans have evolved, there’s always a part of your brain that wonders where we might be headed. What we will look like two thousand years from now. Three thousand. Three-hundred thousand. Every time I thought about it, I factored in certain subconscious assumptions: evolution would continue on the same, slow bearing, generation to generation, and we would be unaware of its progress. It never occurred to me that it might speed up.

Some days after the incident with the heater, the skin on Su’s back started peeling. Nasty, angry flakes like sunburn. She got me to rub lotion onto her shoulders, but it made no difference. She covered up with a shawl, white silk that caught the wind in the back of the four-by-four as we went to the local market with a couple of my colleagues.

It was busy. We got jostled once, twice. I was holding Su’s hand, but a crush of school children swarmed us, loosing our fingers.

Over the heads of the children I watched Su turn. Under her tan, her blood had drained. Her eyes wide with something almost religious. She smiled ever so slightly, and turned her gaze up to the sky, as if she could see the stars beyond the clouds.

Her shawl dropped. The skin on her back creased and released, unfurling a tri-leaf pair of wings. Iridescent and quick like an insect’s. Her arms reached out, she bent her legs, and she jumped. Straight into the sky.

My colleagues howled and the school children dashed away. I was paralysed. It had all happened so fast. The shock spread into my bones and my brain and I’m told that after I picked up the shawl, I just stood with my face to the sky, as if waiting for her to come back down. My coworkers bundled me into the car and took me back to the hotel.

The news broke softly at first, a slow bleed past the gateway of social media. Then CNN got hold of it, and all at once Su’s face was everywhere. It took twenty-four hours to go from anonymity to infamy, but that scant time gave me the space I needed to gather myself. For some minutes after we got back, I sat alone and dry eyed on the end of my bed – our bed – before my brain kicked back in. People would want her notes. Lawyers, journalists or other scientists, I wasn’t sure, all I knew was that I needed to see them first.

I ran to the labs, which were graciously empty, gathered everything from Su’s desk and dumped it all into two black bin liners. I used the hotel photocopier to Xerox the lot of them. Some of the notes were in order, others weren’t. All of the originals were in chaos by the time I dumped them back onto Su’s desk in the shared lab space. When the photocopies were too bulky for my suitcase, I chucked out my own research to make room for them. By this point, the scientific capitals of the world had woken up to the fact that something had happened. I was running out of time.

Taking one final glance around our room, I noticed a copy of Su’s book, Coherence, face down on the bedside table. A quote from Doctor Evans adorned the back cover: In a world that is reaching the apex of crisis, this book provides the evolutionary answers we seek. The decision was instantaneous.

By the time I arrived in Berlin, unwashed at 3am CEST, Doctor Evans had already heard about Su’s feat. Though annoyed about the hour, she did not seem surprised by my appearance. She didn’t even say hello, just nodded and opened the door wider to let me pass. She lived in a brand-new block of flats, but inside her apartment, modernity gave way to haphazard bookshelves and a stained futon that sagged beneath the weight of piled paper. Evans invited me to sit at the table instead, clearing a chair of half-written notes. The internet was rife with rumours but, always prepared for the bleeding edge of science, Doctor Evans was more interested in the truth. She plied me with tea as I haltingly told her what had happened.

The media was not far behind me, and various national security services not far behind them, but Doctor Evans shielded me from the worst of the storm. For good measure, we hid the photocopies of Su’s notes in the broom cupboard where they lay, smouldering with knowledge, as I was questioned and re-questioned by the authorities. I did not understand what had happened and pretended I didn’t have the means to, so they quickly wrote me off as a pining lover. The lesser of two brains, lost without his other half. Once the authorities left, I was ready to drip away into depression, but Evans held me up.

‘It’s time to start reading.’

Su’s research was deliberately cryptic. More than once we found references that appeared to have been planted as red herrings. We worked at deciphering the pages for a few days. Nowhere was there mention of a sponsor. We kept the curtains closed to shut out the media circus and ate the cupboards bare. I fell asleep reading at the dining table and woke up from dreams of wide eyes and sudden jumps. Slowly, obliquely, an idea began to form in my head.

‘I think Su was investigating grasshoppers,’ I said over dinner one night. Tinned spaghetti.

‘Interesting.’ Doctor Evans sipped from a can of coke. She can drink more coke than anyone I’ve ever met. Like Su, she didn’t comment directly on my theory, but pierced it with questions until it resembled something else. ‘Why do you think she chose grasshoppers?’

‘They breed quickly, they’re easy to observe in a lab. We know quite a lot about them already. That’s a good foundation for study.’

‘Study of what? Insects?’

I rearrange my thoughts. ‘No, not insects. Grasshoppers are unusual. They undergo polymorphism. That’s rare, right?’

‘Alright. Why polymorphism?’

‘Why do we ever study anything?’

‘There are holes in your theory, Andy, let’s try to fill them with science instead of pseudo-philosophy, shall we?’ Evans’ intellectual takedowns still had the power to make me feel like a nineteen-year-old fresher again.

‘Well, considering the events of the last week or so, I would say perhaps with a view to making it happen in humans somehow. She could have been messing with her serotonin levels, trying to replicate the circumstances under which grasshoppers become locusts.’

‘It’s a big leap. And experimenting on yourself is incredibly dangerous. Not Su’s style at all.’

I rustled through some papers, looking at the numbers. ‘You’re right. She was monitoring herself constantly, but she never seemed to add any variants into the mix. Her notes still read like she’s observing an experiment group though.’ Painfully, I slot the pieces together. ‘What if the variable had already been added before she turned up in Ghana? If she was studying polymorphism, she might not have been looking at how to make it happen because the switch had already been flipped.’

As one, Doctor Evans and I abandoned our dinner and began trawling through the research again, looking for further evidence. I tried to remember how Su’s brain worked, what labyrinth she might have constructed to hide her purposes, but all I could think about were her wide, pre-jump eyes. The urge to shout welled up in my chest. I tried to quash it.

‘Do you think she knew, or do you think it was an accident?’ My voice cracked. I cried, and Doctor Evans held me like a tiger grips a cub. When I was calm, she made tea and we returned to our research.

As the evidence mounted, it became clear we would have to tell the authorities, men in smart suits who turned up and stood in the living room with stern faces. We explained, twice, three times, then they left. They did not believe us.

Our own evidence base exhausted and our sole possible source of further resources dismissive, there followed a period of listlessness. Evans would put the TV on in the morning and we’d watch mindless daytime shows in our pyjamas until lunchtime. Her neighbour, Laurin, checked in on us from time to time, apparently used to Doctor Evans’ research funks. He worked in the town centre as a satellite designer but came by in the evenings to clean the apartment and urge us to take showers.

Sometimes he coaxed us, blinking, into the wan Berlin sunlight for trips to the supermarket or to walk his ratty dog. The walks were quiet now the media mob had died away, but being out in the open like that made me skittish. I was afraid every person we passed would turn to the sky and jump.

My mum rang me repeatedly, so did my research fellows from Ghana, but I did not return their calls. Threats of revoking my funding landed in my inbox, followed by suggestions that perhaps I was unwell and required medical notes or counselling. Again, ignored.

About a month into this routine, the susurrations began. I woke up first, listening, clutching the duvet to my chin. The cold prickled me as I rose from the couch. I padded around the flat for a long time, holding a tennis racket out protectively in case of attack, trying to find the source of the noise. Finally, I stepped onto the balcony. The tennis racket drooped in my hands as I looked up. At first, I thought it must be the clouds singing, because the whole sky seemed to shudder. The stars shook, the moon trembled. Then, my scientific training took over and I reassessed. The sound was familiar; the same pattern as a grasshopper chirrup but slowed down, and with the dreadful hollow battering of a woodpecker knock.

Doctor Evans slept like the dead. She grumbled when I woke her.

‘Shh. Listen.’ I held up a hand. She rubbed her eyes, trying to make sense of the noise.

‘Where’s it coming from?’

‘The sky.’

She got up, frowning, and padded to the open window. ‘Shit, look at the stars.’


‘Am I dreaming?’

‘No.’ I joined her by the window, both of us staring slack-jawed at the shuddering sky.

‘What is it? I know that noise, I’ve heard it before.’

‘I think it’s teeth,’ I replied slowly. ‘Human teeth. Chattering.’

Both of us kept our eyes fixed on the sky, knowing that if we looked at each other, we wouldn’t be able to keep the next logical assumption at bay.

We stayed awake all night, turning on every light in the house, flitting between twenty-four-hour news channels and our haplessly filed notes. Time zone by time zone, reports of the sound came in from around the world. Parties in New York came to a standstill; Hong Kong and Tokyo office blocks emptied, their workers pouring out to stare at the shaking shadows cast by the sun; back in our own Australia, schoolchildren were sent home for the day. One after another, we could sense our neighbours waking up and tramping out to the street to see what was happening. Someone fired a gun at the moon.

Doctor Evans and I were more pragmatic, scrambling through online recordings of insect calls and papers about the resonance of human teeth but we were in an academic no-man’s-land. After a while, the susurrations started to get to me. It must have been terrifying for the people who didn’t know what was happening, being bombarded with that constant pattern of sound, but knowing it was the chatter of human teeth was just as unsettling. That it was Su’s teeth- I thought of them wearing down grain by grain and I shuddered.

By 6am there had been another jumper, a Mr Atman of Mumbai, sixty-four, white-haired, and as far as anyone could tell, utterly ordinary. He had been employed in a workshop on the edges of a slum, shaping tin foil into takeout trays like the ones piled up on Evans’ dining table.

‘Do you think she’s calling people to her?’ It was a horrible thought, and I wished as soon as it left my mouth that I hadn’t said it. Doctor Evans gave me a hard look, but I couldn’t bring myself to believe it of Su. I glued myself to the news reports, trying to find evidence that it wasn’t the case.

‘The strangest bit is Subject Atman’s behaviour since he jumped,’ said a consultant on the BBC World Service. He was there representing an emergency department set up by the UN to investigate the susurrations and any possible connection to the jumpers. Doctor Evans bristled that we hadn’t been invited to join the team. I bristled every time the consultant called Su ‘the Suharto Subject’.

‘The Suharto Subject took off straight up – like a rocket, at ninety degrees to the ground – and she carried on into space once she left the atmosphere. Subject Atman is different. More like a plane, he took off at a slight angle, circling the earth in an orbit until he reached the edge of the upper atmosphere.’

‘And where is he now?’ Shock bled through the newsreader’s exterior.

‘Still orbiting the Earth, as far as we can gather. We are of course concerned about his wellbeing, but our primary focus must remain stopping any more jumpers from leaving.’

‘Do you believe the noise we have been hearing today is a possible cause for these jumps?’

‘We are not ruling anything out at this point in time, but as the Suharto Subject jumped before the susurrations, our best guess is that at most she could only be a catalyst. You’ve got to understand, this is academic territory no one has-’

The interview went on but I turned the radio off. ‘See there. Just a catalyst.’

Evans scowled. ‘If you believe that team, you’ll believe anything.’

By dinnertime, there had been three more jumpers, a toddler and her babysitter from Seattle, and a translator from the British Embassy in Brazil. They all joined Atman in his orbit.

In desperation, I began recording the susurrations. It repeated once every five minutes but I couldn’t make sense of it. If it was a call, the code should have been simple. Easy-to-follow. Flat pack instructions for human evolution. The sound was purer on headphones, isolated and almost comforting, as if Su was right there with me. Briefly, I wondered if this was how it sounded to Atman and the other jumpers, before I realized with a flip of the stomach that of course it wouldn’t be. Their distance from the planet surface and the speed at which they were orbiting would make it sound completely different.

I ran across the hall and thundered on Laurin’s front door.

‘Andy? It’s past midnight.’

‘I’m sorry.’ I barged into his apartment, shutting the door behind me. ‘Really, I am, but we’re going to need a recording of the susurrations from a satellite as close to the orbit of the jumpers as possible.’

‘I can’t do that, Andy. It wouldn’t be legal.’

‘I will give you everything I own.’

‘Oh yes, and what’s that? Two rubber bands and half a Chinese takeout?’

Two days and ten jumpers later, Laurin returned from work with a somber look on his face and thrust a USB stick into my hands. The three of us sat around my jury-rigged audio equipment, isolating the repeat and deconstructing it in every way we could imagine. It was Laurin who figured out that, if you slowed it down enough, at the jumper’s precise orbit the susurrations sounded like Morse code. Instructions for a trajectory heading out into space.

‘Breadcrumbs.’ The relief washed over me. ‘She’s not triggering the jumpers, just guiding them once they’ve leapt.’

Apparently the UN’s committee of scientists had figured this out as well, and they issued a statement saying that they now believed the transformations in jumpers to be caused by some kind of infection. Anybody experiencing a hardening of skin, a lack of appetite, an incredible thirst or flaking rash on the back should report to the authorities immediately. Despite the number of false alarms this warning engendered, the frequency of jumpers continued to increase, so much so that the news outlets began to speculate whether this might be the fate of all humans.

The idea filled me with a dread of being left behind, as well as an equally strong fear of becoming an unknown thing. My body became riddled by phantom symptoms: my back itched but remained smooth, my appetite diminished and returned, I drank so much I had to pee twenty times a day. Increasingly, Su became a point of return. I had imaginary conversations with her to get myself to sleep, as I brushed my teeth, or when I had a research block.

‘I know you talk to her still,’ Evans said to me as we stood out on the balcony one evening, watching the shaking stars pierce the dusk. The susurrations droned. ‘When you think you’re alone. I hear you.’

I didn’t know how to respond. ‘God, I wish I could jump.’

‘I’m very glad you haven’t yet.’ It was the first time it occurred to me that Evans might actually enjoy having me around, beyond the obvious research bonuses. ‘I wish we were on that UN research team. The resources they must have! Mind you their theory makes no sense. If it was an infection, you’d have jumped long before now. You were around Su all the time, kissing and whatnot. You would have caught it. But if it’s not an infection, then what is it? It’s probably something really obvious that’s been staring us in the face all along. Something we’ve studied before that we didn’t think was releva-’

The answer came from Doctor Evans, really. It was her words that brought the grasshopper research back to me. I cut her short. ‘What about environmental circumstances? Chemical imbalance in the air, or exposure to a particular kind of radiation, or something. It could even be simple, like with the grasshoppers. It could be crowds.’

Evens opened her mouth to start piercing my argument, but for the first time ever, I was ahead of her.

‘Hear me out! Grasshoppers change when they get too crowded because it’s a sign of drought. They have to move on and find a new food source. Look at the world now: the Earth can only support ten billion people if we live frugally and become vegetarian, but most of us aren’t really paying any attention to that. Soon enough, the planet won’t be able to support our numbers anymore. If there was a switch of some kind which could figure that out, we’d probably migrate just like the grasshoppers.’

Evans closed her mouth, gazed off the balcony, dragged on her cigarette, then looked over at me again. ‘Crowds?’


‘Huh. Imagine that.’

It’s still the theory I believe now, all these weeks later. Not that the UN research committee agrees with me. Jumpers have become so normalised that the news programs report on other catastrophes and simply print the names of those who’ve leapt in the middle pages of newspapers, beside the wedding announcements and obituaries. But we haven’t, any of us, forgotten. We are waiting. The jumpers weigh heavy above us, temporary and tensed for another leap any second now.

I dread the moment they leave. I try to imagine which would be easier: a quick bereavement, the entire swarm flying out into the darkness at once; or a slow fading, each of them sloping off one by one towards the source of the susurrations.

I attend rallies when I don’t believe in the politics, go to gigs to launch myself into the mosh pits, take rush hour trains back and forth, trying to trigger the instinct to leap. At night, Doctor Evans and I watch the growing cluster of jumpers orbiting above, the swarm so large now its thin pinpricks are visible even to the naked eye.

When I see people I used to know before Su jumped, they ask me why I think she was the first. I tell them I don’t know, because that’s the simple answer, but privately I wonder if it’s because her mind was so wide open that she was able to internalise all the ideas the rest of us could only comprehend from a distance. The possibility that she might not be the solitary, self-sufficient human thing she had been taught to believe she was. Up on the balcony, the red string around my wrist throbs. A moth settles on my hand and I still myself, trying desperately to convince us both that I’m just another bit of earth.

‘Do you think it’s that easy?’ I keep my eyes locked on the moth.

‘Nothing is ever that easy.’

‘But it is possible.’

‘Everything is possible.’