For a moment the wind drops and everything is completely still and quiet. I don’t know whether I’m more afraid of us being totally alone, or of what might happen when we do find someone. Either way I keep looking over my shoulder.

‘Tell me how there is this Wilderness,’ Kay says. ‘Tell to me about the war thing again.’

‘We went to war to try to defend another country that the Greater Power had invaded.’

‘What’s invaded?’

‘They brought loads of soldiers – fighters – into a country and started telling them what to do. Of course the Greater Power didn’t like us interfering when we tried to help, so they attacked us too. Using new weapons. Lots of bombs.’

‘What’s bombs?’

‘They drop them out of the sky and they explode.’ I mime an explosion by scrunching my fingers and flicking them out. ‘They break things, even big things, they make buildings fall down.’

‘Like at the Academy when there was the fire and then there was that boom! and it made everyone fall down?’

‘I don’t think that was caused by a bomb, but similar to that. Where we are now was the worst hit because the capital used to be around here somewhere.’

‘How did the war stop?’ she asks.

‘The Leadership stopped it.’ I frown. ‘Or so they claim.’ Come to think of it, what do I really know about the Long War at all? ‘That’s what I was taught in school anyway.’

Kay nods. We both know that neither her school nor mine was a place for reliable information.

The black shape in the distance gradually resolves itself into the remains of a group of houses. They must have been hit by a bomb. Only one front wall stands alone, with its windows smashed and its wooden veranda in splinters. It looks like a mouth full of broken teeth.

The rest is not much more than a pile of bricks and timber. When we reach it I pull a plank from the wreckage and Kay and I manage to hack at it with flat stones until the wood splinters into a reasonable point, then I stick it in the ground, so that we can make another shadow compass and check we’re heading in the right direction. While we’re waiting for the shadow to move, Kay starts shifting bricks and hunks of plaster.

‘What are you doing?’ I ask. ‘Some of that stuff is sharp.’

Kay rolls her eyes. ‘It’s not sharp things I’m worrying about.’ She looks behind her. ‘I want to find a weapon.’

I would like a weapon too. If only I had a gun, then all that weapons training in the Future Leaders sessions at the Learning Community might actually be some use to me. But there’s nothing useful in the heap of rubble. Kay has to settle for half a brick, which she keeps in her hand at all times.

Looking at the shadow compass I adjust our course a little and head towards a group of buildings in the distance. We cross several fields of mud sprouting nothing but a few sickly weeds and surrounded by hedges that are not much more than desiccated clumps of twisted twigs. Then we find another undulating road to follow. It must have been pretty once, looking down the hill at the fields. But now everything is grey and withered. I don’t understand why the weeds aren’t thriving. Surely, left untended, this place should be a riot of greenery? There’s something very wrong here.

When we reach the buildings we find the remains of a village. The wind whips brick dust in my eyes. I squint to take in the devastation. Where we stand is barely even recognisable as a street. You can’t pick out individual structures. It’s just piles and piles of bricks with lengths of wood sticking out. I have to remind myself that these bricks once made someone’s home and these shards of wood came from the furniture they used every day.

Behind these mounds is half a house, its side ripped open and its insides spilling out. Twisted between the bricks there’s a jumble of sun-bleached clothes tangled like intestines. Beyond that is more rubble, but on the far side of the village is a group of houses still standing, although they slump against each other like wounded soldiers. What happened to the people who lived here?

Kay is picking her way through the mess.

‘Can we drink this?’ she asks, pointing to a pool of rainwater that has gathered in a dented plastic roof of some kind.

I take a look at the water. It looks all right, but it’s bound to be full of bacteria. We haven’t got anything to filter it with. My tongue feels coated in grit.

I shrug. ‘We may as well. This is probably as good as we’re going to find anywhere.’

The puddle is quite deep and we manage a few mouthfuls each. The water tastes bitter, but it feels really good slipping down my throat.

I hunch my shoulders against the wind as we make our unsteady way between the remains of houses. I can’t shake the feeling that we’re being watched.

At the centre of the village is a crater the size of a football field.

Kay’s eyes widen. ‘Is that where they bombed the bomb?’

Dropped the bomb, I think – but I don’t say it because my jaw has seized up. It’s like the middle of the village has just disappeared.

Kay stares into the crater. ‘Were there houses there?’

I nod.

‘But there’s no things left. No bricks and things.’

I don’t know what happened to the remains. It’s like they were vaporised. What kind of bomb does that? Causing buildings to collapse is one thing, making them disappear is something else.

Kay has already turned away. ‘There’s some standing-up houses. Let’s look for food.’

I tear my eyes away from the crater.

Kay makes her way over, between bricks and roof tiles, into one of the few upright houses. I eye its walls with apprehension, but I climb in after her anyway.

Inside, the ceiling has partially collapsed. The front door has been blown onto the stairs. The furniture and carpets are covered in a thick layer of plaster and broken glass. It’s hard to tell what’s what.

The next house we try seems less likely to fall down on us at any moment. When we walk into the sitting room a shiver goes through me. Nothing has been touched. The green armchairs are pointed towards the old-fashioned TV. There’s a book about gardening splayed face-down on the coffee table. A piano in the corner has a jumble of music stacked on top. It’s like we’ve stumbled into someone’s home. Except there’s a chill wind blowing through a broken window.

One room that isn’t untouched is the kitchen. All of the cupboards are bare. It looks like someone has cleared them out a long time ago. Even the cutlery drawer has been emptied. It’s the same in the next two intact houses we find.

In the third house, Kay pulls open a cupboard under the stairs. Behind the coats and wellies and a pair of tennis rackets she finds a shelf holding four pots of homemade jam. The jars have rubber seals and they haven’t spoiled in all the years that they must have been sitting there gathering dust.

‘This is big good,’ Kay smiles, when we crack open a jar to share.

I know it’s rash to finish a whole jar, but I’m so hungry and it’s great to see Kay enjoying the sweet taste. I find a bag on the row of pegs on the back of the cupboard door and put the empty pot and the remaining three jars in it to take along with us.

Whoever made this jam had no idea that we would be eating it. What happened to them? Did they die in the war? Are they still alive on the other side of the fence? Either way, I’m grateful for the jam in my stomach.

Out in the rubble-filled garden, Kay points at a small wooden hut.

‘What’s this?’ she asks.

‘It’s a shed.’

Kay is already wrenching open the door. The wood is so weathered that it’s crumbling away at the corners like biscuit.

Inside, the tiny space is crammed full of junk. Plastic sacks, spades, rakes, boxes, buckets and a giant fabric umbrella.

‘It’s rubbish,’ Kay says.

‘Wait a second.’ I pull a folding chair out of the way.

‘What is it?’ Kay asks.

‘It’s a bike. In fact,’ I say pulling back a rustling tarpaulin, ‘there are two – which is good.’

‘Why? What do they do?’

‘They move.’

We had a number of bikes at the Learning Community. They didn’t make much of a fuss about Physical Education there, but once a week we were supposed to get some fresh air. Wilson and I usually opted for cycling around the grounds since it seemed like less effort than anything else on offer. The Specials at the Academy were required to exercise every day, but I never saw anything that might be described as equipment there and going outdoors for a ride would never have happened.

‘Show me,’ Kay says.

‘Okay. Grab that one.’

We manage to yank the bikes out of the clutter and drag them outside. We have to haul them over and between the mounds of bricks until we reach a clear stretch of road leading out of the village. I swing my leg over the saddle and wobble forwards. My legs are still weak from that dreadful crawl through the pipe, but soon I’m gliding along.

‘Blake!’ Kay laughs and claps her hands as if I’ve performed a conjuring trick.

‘It’s easy,’ I say riding back to her. ‘You’ll soon pick it up.’

Half an hour later, Kay still can’t find her balance. Each time I let go of the back of her bike she sways and crashes to the ground.

‘Stupid thing,’ she says and inspects her skinned palms. It would almost be funny to see Kay’s disbelief that she is struggling with a physical activity if it were not for her frustration.

‘Don’t worry, you’ll get it,’ I say, but she only scowls in return.

Eventually, she does get it and the first time she catches her balance and makes her way wobbling down the road we both shout with delight.

The sun is stronger now and it catches Kay’s hair as she rides away. She’s gorgeous. For a moment I forget to look over my shoulder. I forget about listening for movement in the ruins behind us and I just think about Kay. I want to hold her. I want to be in a place where she is learning to ride for fun and not because we’re desperately seeking a group of people we may never find. If things were different we could be teenagers who don’t have to worry about anything except schoolwork and having a good time. We could ride all afternoon and then we could take a break and we’d talk and kiss and touch for hours and hours and nothing would stop us from being perfectly happy.

But that’s not the way things are.

And they never will be, unless we make it that way.