I can’t say how long we have been playing this game, but I know I have to win this time. Otherwise, it’s my last trip.

The rules are simple, and always the same, even though laughs explained them again as the three of us hovered above the pavement outside the station in the grey morning. Three jumps each, three objects to collect, one finish line. No interacting with each other’s shells. No leaving a shell in more trouble than you found it in. First to the finish wins. Simple. Except that nothing about being inside a human body is simple.

We all start together – laughs, burps, and me – three adolescents blinking into existence behind three pairs of human eyes outside the station. I watch the commuters pour past us, trapped in themselves, eyes fixed somewhere else. That’s the thing about Dalston – the density of people performing mutual invisibility. Mad, really, that we can make people behave so strangely and no one cares. Madder that no one has ever noticed in all the years we’ve been coming here.

The grey-glow wobble of my friends pulses at the edges of them as we separate. Some minds are easier to jump into than others – you can feel the difference before you’ve even committed, like testing the temperature of water with your foot. I notice that laughs and burps have each chosen attractive, able-bodied women. Last choice, as always, falls to me. I ignore the message icon as there are more important things to concentrate on here.

I look down at my new hands. Broad, cracked at the knuckles, nails bitten to the quick. The body I’ve ended up in belongs to a homeless man. He’d been sitting against the wall of the Sainsbury’s Local with a paper cup and a dog. The dog looks up at me with immediate suspicion. Animals often know.

Brief panic, and that hot, light/heavy feeling like blood returning to a dead limb. I never let the others see how much I hate the taste of this. It’s just what we do at this age. The weight of carrying a heavy object a small distance: the ache is bearable because you know it won’t be for long. Now I am him, I can’t smell him at least. His ankle is screwed; I should have spotted that.
I let the dog’s lead drop. I know. Cruel. But I don’t have time. I watch it trot away with the dignity of something that has always known it would be abandoned.

Up ahead, I can see laughs – or rather, the woman laughs was wearing – moving fast through the crowd, something purposeful and wrong about her stride that would only register as odd if you were looking for it. There’s always at least one man looking. burps has already gone. I have no idea which shell he’s taken.

I check my jump tech: two blinks, and the ghostly numbers appear at the side of my eyeballs. The counter reads one.
One. It should have read three.

I know immediately what’s happened. laughs. Before the race, the small adjustments – someone jostling me, the hand on my shoulder – I’d thought nothing of it. Now I know. An illegal move. If I raise it with the officials on the ship afterwards, laughs would deny it. laughs always denied it. He had gotten away with worse, plus they’d say it was only a game. Well, if it is, then why is he the one whose future is secure and I’m the one on a final warning?

One jump left. Three objects to collect, one checkpoint between here and the finish.
The high street opens up ahead of me. Bulging red bin bags full of empty drinks containers from the previous night sit outside every third business premises, and the cashpoint on the corner is surrounded by satsuma peel and soggy cards for a taxi company, drying in patches on the pavement.

‘I’m not racing!’ a boy whines, somewhere behind me, after friends who have already left him. I know how he feels. The young ones here still have to go through their own trials to prove themselves.

I need the fifty-pence piece first. I check the pockets of my shell. Nothing but an empty bag, greasy empty plastic and card packaging for something long gone.

Up ahead, I make out the commotion around laughs. Three men, maybe four, have arranged themselves around her in the way that men do – not quite blocking, but blocking, each acting ignorant of the others. She’s being slowed down. This is the tax on the body he’s chosen, and *laughs hasn’t accounted for it. I always feel sorry for the females on this planet. But that’s why I never use them; it feels like they’re already taken for a ride.

She says something sharp. One of the men laughs. I watch her calculate, knowing it was laughs. Then one of the men peels away from the group like they have somewhere to be. Walking too fast, purposefully, and in the direction of the first checkpoint.
burps. Of course.

A kamikaze pigeon drops from nowhere, seems to reconsider, and sweeps up over the head of a man arguing on the phone outside the betting shop. I watch it go. Second place, laughs had always said, is where the clever ones end up.

No rules about what species you can jump into, laughs had said once, during a long-distance race. Some birds can fly above everything but are impossible to steer and don’t last long on the ground. Can’t carry anything heavy either. Dogs could be useful if you could detach one from its owner. I’d thought then, and thought now, about those neck leads. Should have kept the one I had.

A wiry woman presses herself behind the arm of a burly security guard next to a broken window of the Poundshop – yes, here they even guard items that cost one pound. The guard’s eyes look off to the side, suggesting she’s done something, though his expression says the cost of this association is entirely hers to pay. An annoyance. Maybe the way the public sees him now. He stands very still, and that’s when I see the silver coin glinting a foot away from his foot.

I swoop down to grab it, and the security guard flinches, then laughs when he sees the fifty pence in my crusty hand.
Now I cut up the camber to where the shop fronts had tiled entrances, and through a window I catch a glimpse of old Turkish men playing billiards in the back of a café, unhurried, the balls clicking in a different kind of time. I’d always wanted to try that, but we’re not that kind of tourists. Certainly not now.

The swollen ankle is slowing me down, but I know it will be a lot more swollen when I’m done. Still within the rules, though – preexisting condition.

Mercifully, the apple is easier. A market stall, a distracted vendor, and the ethics of theft inside a borrowed body are – complicated. I pick one and try to return it, but seeing the state of the body I was in, he waves a hand to say keep it. Where we’re from, this would be theft, but we respect the local customs. My body’s neuroreceptors suggest that this is the first fresh fruit he’s held for some time. He can have it when I’m finished.

‘Shut up, man,’ a woman shouts, apparently at the baby in her pushchair, wheeling round as she nearly loses a pompommed slider in the gutter. The child looks startled, then philosophical.

One jump left, and I’m not sure I even need it. One object and the finish line; one jump between me and winning.
The finish line is the broken relay box, its battered green open, a portal-point, the kind of architecture that exists in every city on earth and that we have always used, that humans built and never quite knew why they were building.

My comms had been off since the start of the race. Required, of course; no outside advantage. I’d ignored a return-to-ship message earlier on the emergency channel. I’m not that dumb. Somehow laughs has hacked it. There’s literally nothing he won’t do to win.

The incessant beep tells me that a message is waiting, but I won’t be distracted when I’m so close.

I jump into a pacing man in a backpack for the final stretch. Physical pain swaps for stress and anxiety, but the limbs feel half the weight. I don’t turn to see but can hear the homeless man slump to the gutter after his hand drops from my shoulder. I wonder how the shells feel once we leave them.

They always add the last item at the end of the game. We’ll need to demonstrate resourcefulness as adults when we get back to our world. Last item: a floss toothpick. Easy; these things are everywhere. There’s one at my feet. A woman looks at me when I pick it up.
‘Ew, Marcus.’

Perhaps this is the human’s partner. The fake plant in the window of the nail salon is exactly the same as the one in the travel agent’s I just passed.

In any case, I made it. I touch the green relay box. The metal feels warm under hands that aren’t mine, a body that’s already beginning to feel too small for me. I’m first.

Then the light flashes in the south, between the buildings. Not sunrise. Too fast, too flat, too total.

Immediate atmospheric change. I can tell, even in this stolen, broken body. Then it hits me. The return-to-ship message was real.

I look back down the high street – our race track – and recognise laughs and burps in their last shells. They’re the only ones running. Soon, everyone will be running, but there will be nowhere to run to.

Across the road, pink paint has been spilt and long since dried. Various footprints trace a communal dance around the splash. It’s part of the street now.