Getting into Mid from Under’s easy if you know where to go. There are places where the wall’s broken, or where the trees are tall enough to climb and jump over from. I’ve been sneaking up there since I was a kid, running away from my chores at the Dorms to find more food or interesting shiny stuff for Finn to play with. The others used to act like I was crazy for it, amazed when I came back free of bullet holes. Finn cried a lot. He’d throw his arms around me and beg me not to go every time. I’m fairly sure the Dorm Mother knew exactly what was going on too, especially as I got older, but she never said anything. Probably because she knew she couldn’t stop me - that, and if she kicked me out she would’ve lost the only person who could teach the others how to read.

  Getting older made it harder. It’s easy enough to slip through cracks in the walls when you’re short and twiggy. When you’re nineteen, you’ve got to be more discerning. Peacers probably aren’t going to bother chasing down a kid, but an older teenager is a different story. Luckily there are still districts in Mid where the Peacers don’t really patrol. Trick is to sneak in there, then run along the jagged roofs and up the stone steps to the districts closer to Top. That’s where the nice shops are, the merchants, the street markets. Plenty of pockets to pick and houses left unoccupied. I tell Finn I go for people who look like they can afford to lose a ring or a bracelet. In reality, I don’t care. If they’re in Mid then they’re doing better than me. If they even have a bracelet then as far as I’m concerned they can stand to lose it.

  I realise I’m speeding up and slow down. The tiles on this roof are old and brittle. With my next step, one of them edges free and goes tumbling down into the shadows. A crack echoes out from below and I wince, looking back over my shoulder. No blue uniform. He wouldn’t have followed me out here anyway. Those from Mid rarely come into Under, and certainly not so close to nightfall.

  My heart’s still galloping though, and there’s a sharp pain in my side from the sprint over here. The bullet had whistled past my cheek, an inch out, and then exploded into the wall. That mess of brick would have been my skull if the Peacer’s hand had twitched.

  Maybe I need to stop this. Maybe Finn’s right, and I need to find a real job. I could join the Association and work the lifts - or ask Big Jay if she needs a hand with the pub…

  They’re empty thoughts. I’m not going to do that. I’m going to keep doing this, even if it gets me killed. I’d rather a life where I struggled than one where I didn’t try at all.

  I dig my knuckles into my side, grimacing, and pat over the cloth pouch under my shirt to make sure it’s still secure around my waist. I need to stuff more cloth in there - I landed a coin purse earlier and the stupid thing keeps jingling. It’s how the Peacer got me and I’d rather avoid the same thing with the gangs. Careful, I pad across the roof and hop down to the next one. Down, down, down. I’m careful where I step, sticking to the shadows, deepening as night crawls closer.

  When I reach the next set of crumbling stone steps, I hear voices.

  ‘...That’s on top of the extra we’ve already been doing last month.’

  ‘And who’s to say it’s going to end next week? They’ll just keep extending our hours until we’re working in the dark.’

  ‘Come on, they wouldn’t do that.’

  ‘Get real, boy. Of course they would.’

  Pit miners, I conclude. I eye the sun, the weak, purpling dregs of it that are left, and wonder if I’ve got time to stop and listen. If they’re planning something, it would be good to know before darkness descends entirely and I start tempting fate. Under’s the most exposed part of the city, and our walls are old and problematic. Every month or so a section caves in and then it’s a rush to get it patched before the Katerakts notice. Years ago, it would get fixed within a day; now it takes almost a week. Top has sucked up all the chemetal workers in the city and put them to work reinforcing their own, metres-thick wall. Never mind that they’re the safest in the city - for the Katerakts to get to them, both Under and Mid’s walls would have to fall, along with all of us poor bastards living here.

  ‘I say we strike,’ another voice says, and the decision’s made for me. I scurry down, slipping along old metal balconies and swinging myself to the next roof with a faint jingle.

  They’ve chosen their meeting point well: a dusty rooftop square, close enough to the wall that there won’t be any lingering overseers. There are more of them than I expected, a dozen men and women all dressed in pale grey mining rags. The worn fabric flaps off toothpick legs and arms, skin as ghostly white as their hair. Chemetal bleaches the colour out of everything, even humans. My own palms are mottled white in places, a spiderweb of poverty stamped into my skin.

  ‘Have you lost your mind?’ a man with a narrow, wolfish face scoffs. His muscles stand out, all bunched and stringy in a way that doesn’t look quite right. They don’t get fed enough in the Pits. ‘You remember the last strikes, don’t you? They’ll wait for sunset and push us all over the edge!’

  Grumbling ensues.

  ‘But that was last time,’ a younger man pipes up. He still has brown streaks in his hair. And they’re not even using it for us, for our wall - they’re taking it for theirs. That new dig sits all for them, it’s unfair!’

  I wince at the thought of weeks of wheezing a new dig will bring.

  ‘I reckon…’ The young man swallows and stands his ground. ‘I reckon striking’s the way to—‘

  ‘Keep your damn voice down!’ the wolfish man says, taking a step towards him. ‘Peacers could be anywhere, you want to get us all killed?’

  ‘They’re not down here though, are they?’ the young man bites back. ‘They won’t come this close.’

  ‘We’re not striking!’

  ‘What else we supposed to do,’ a woman breaks in, loud enough to cut them off. I can’t see her face, just the back of her hair, white with a crown of black dust. ‘Sign up and get sent to service instead? We’ll die anyway! I can’t— can’t do this anymore!’

  Another man puts his arm around her. ‘Mellie,’ he says softly, and then the air thumps with noise.

  It’s so loud that I instantly duck, and my coins give a sharp jingle. Nobody hears. They’re too busy looking up at the sky, where a shock of lime green powder falls in a contained cloud. High up in the east, bright against the darkening sky. Green flare - Katerakts sighted. They’re coming tonight.

  I become horribly aware of the time.

  The wolfish man curses. ‘We’ll meet again next week,’ he says as people start to scurry away, drawing their ragged grey scarves up to cover the lower half of their faces. ‘Stay safe! Stay strong!’

  Someone says something else but I don’t hear it. I’m already gone.

  It probably says a lot about Under that even with a flare so close, the pubs are still all open. To get to The Old Boat I have to navigate my way down, close to the Pits. The buildings here are old and stony, and at a slight slant - like some great wind ripped through the streets and pushed it all just a little bit out of line. Like the rest of Under, it’s been built up as much as it can: houses on top of houses, streets between the balconies. You can forget about city planning. Now there’s dead ends and half-rotted staircases that don’t lead anywhere and whole sections where the structures have fallen into rubble.

  In the darkness though, it doesn’t look too bad. The street glitter sometimes, from the dust blow in from the Pits outside the wall. And the Pits themselves can be beautiful too. They’re constantly sighing out plumes of thin grey smoke, and on still nights you can see it writhing and twisting in a dance up towards the sky.

  Anyway: The Old Boat. It’s a local favourite, hidden at the end of a tunnel made of overlapping slabs of rock. Inside, a wooden rib cage holds up the sagging plaster of a once-grand residence. It’s gloomy and smoky, and smells so much like ale that if you wrung the whole place out it would probably go splashing down the street. I like it because it tends to draw a quieter crowd than the others, like The Bleeding Horse, which lessens your chances of getting beaten up or shanked by a miner having a bad day.

  Tonight there are only a few dust-stained regulars, nursing their tankards, and a middle-aged Flipper tinkering away at the bar with something metallic and complicated-looking.

  Big Jay looks up as I enter and gives me a big gap-toothed smile. She’s a short, bulky woman who I’ve known for years. I used to get reading lessons in the back room here. ‘Evening Addie,’ she greets as I approach. ‘Finn isn’t here yet but your other friend is.’ Her grin edges wider. ‘The handsome one.’

  I am excruciatingly aware of the way my face goes beet-red.

  ‘Go say hi,’ Big jay says, trying not to laugh. ‘I’ll bring it over to you.’

  ‘Thanks,’ I manage to get out, turning stiffly and searching out the room.

  Big Jay’s talking about Tom. Tom is a newcomer to Under. We found him wandering around the streets just before sunset, on the verge of tears. He won’t talk about what happened, but over the last few months Finn and I have pieced together that he somehow lost all his money in Mid and ended up getting chased out. He goes around telling everyone he’s from Under now, which is sweet but completely impossible.

  When I find him, sitting alone in the corner, his spine is impeccably straight and his dark hair is combed neatly to the side - with not a hint of white to be seen. Everyone else here is slumped over their drinks or the table, head in hand and exhausted from a day’s work. He sticks out like a sore thumb.

  He frowns and turns, and we make eye contact. My belly flips, but I ignore it, heading over.

  Tom is not interested in me. I know he’s not. But I still surreptitiously tuck my hair behind my ears - pointless, it’s curly enough that it just comes springing back - and wipe the sweat from my forehead. God, I probably stink, don’t I? All that running…

  Well, it’s too late now. I yank out the chair opposite and take a seat. Don’t make it weird. Treat him like Finn.

  ‘You’re late,’ Tom says, but he’s smiling. ‘I thought we said seven?’

  ‘Finn’s not here yet either, I say.

  ‘Clearly tardiness is a family trait.’

  See - who says things like ‘tardiness’?

  The narrative has been illicitly obtained; should you discover it on Amazon, report the violation.

  ‘I’m only…’ I lean back and peer at the clock on the wall. I’m twenty minutes late. I divert: ‘I bumped into some miners on the way back.’

  Tom frowns.

  ’Not like that,’ I say. ‘They were talking about striking.’

  He leans back in his chair and sighs. ‘They won’t do it.’

  ‘Yeah,’ I say. ‘But apparently there’s going to be a new dig site.’

  That gets his interest again. ‘So soon?’

  ‘Maybe we’re running out of chemetal.’

  His frown deepens. ‘We wouldn’t need so much of it if those idiots stopped blowing up the walls.’

  ‘You reckon it’s them? The miners?’ That’s also the reason I stopped to listen earlier. Pit workers have access to explosives, after all, and a motive. Although if it is them, they’re shooting themselves in the foot. More damage to the walls means more hours spent mining the chemetal for the repairs.’

  ‘Who knows,’ Tom says. ‘How was Mid today?’

  ‘Fine,’ I say on reflex and then freeze.

  He’s smiling now. ‘So you went there again? Finn’s not going to be pleased.’

  ‘Finn,’ I scowl, ‘doesn’t need to know.’

  Tom is unfazed. ‘What did you get then? Anything interesting?’

  I glance at the door and then around the pub. Big Jay is pouring my drink and chatting with the Flipper at the bar. Old man Thesp is there too, slugging back a pint like his life depends on it and mumbling to himself. Nobody’s looking over.

  I slip my hand around the bottom of my shirt and unbutton the pouch. I fish around until I feel the sharp scrape of cut wire, and drag out onto the sticky table. The battery - I think that’s what it is, anyway - is the most interesting thing I picked up. It’s around the size of my palm, an elegant cylinder made of glass and gold. I had to cut the metal wires locking it in, and the tail ends curl up like decoration. It’s pretty.

  Tom takes it off me, turning it around in his fingers. ‘Where did you get it from?’

  ‘A clock in a town square. It’s new - they must have fitted them all with it last week. I reckon it’s something to do with the sun, but maybe…’ I trail off - Tom’s hunched over, shoulders shaking. ‘What?’

  He looks at me and starts chuckling again. ‘You took this from a clock? A public clock? What must they have thought!’

  I scowl and swipe the metal thing back. ‘They didn’t think anything, because nobody saw me.’ Complete lie - a Peacer had rounded the corner right as I’d cut the last wire. Hence the shooting. ‘You know, if you came with me, you could point out the really valuable stuff. And you could tell me where to go.’

  ‘No thanks,’ Tom says breezily. ‘I’d rather keep my body free of bullet holes if it’s all the same to you.’

  The door trills. Both of us look up as my brother ducks inside.

  Finn looks tired. His dark curls hang over his face and there’s a scorch mark on his shirt that wasn’t there this morning. His glasses flash in the light as he heads to the bar and the Flipper perks up. Finn’s famous with the Flippers around here.

  ‘I bet Rodger kept him late,’ I say, frowning.

  ‘Have you ever met him?’ Tom asks

  ‘Rodger?’ Tom nods. ‘Yeah,’ I say. ‘He’s an idiot. He inherited the shop from his mum but he’s got barely any Affinity, can’t even fix a lamp. If Finn wasn’t there, he’d lose half his customers.’

  Finn’s wasted in a repair shop. He’s got the strongest Affinity of anyone I know, can take what looks like utter junk and somehow create incredible things: self-sustaining water purifiers, honing catapults, smoke bombs, no-slip pocket watches - you name it. If he’d have been born in Top, he’d be at the University by now. Even if he’d been born in Mid, he would have gone on scholarship. But there aren’t any scholarships for those of us in Under. Most people assume we can’t read. I watch him greet the Flipper and peer down at whatever the man’s tinkering with. The Flipper begins talking excitedly, gesturing with his hands. Some of Finn’s tiredness falls away as he peers closer, nodding absently.

  ‘Surely if he needs Finn then he can’t treat him too badly?’ Tom says.

  I look back at him, my mouth flattening. ‘He knows Finn needs the money. It’s the hand. It’s hard to find shops that’ll take him on with it.’

  Tom nods but he looks disappointed. I don’t blame him.

  Ten minutes later, Finn arrives at the table with both of our drinks. ‘Big Jay says sorry for the wait,’ he says as he thunks mine in front of me. Ale slops out onto the table.

  ‘How was the shop today?’ I ask as he takes his seat. ‘Rodger kept you late.’

  Finn’s smile dims a fraction. ‘Yeah. He’s got it into his head that I’m doing something to the electrics for the radios. He said I had to check them all again which took a couple of hours. It was fine though. They were fine in the end.’

  ‘He’s an asshole,’ I say.

  ‘Yeah,’ Finn sighs, reaching for his drink. ‘He is.’

  ‘You can take of the strap now, can’t you?’ Tom asks, eyeing Finn’s hand.

  Finn brings his left hand out flat on the table, then unbuckles the prosthetic. It’s self-made - he’s been refining it ever since he was big enough to hold a welding iron. But the mechanisms burns out every two months, and the constant heat in the lead-up to it often burns his hand too, especially if he wears it all day without a break. When the strap finally unpeels, the skin around his palm is bright red, and the stump where his last three fingers should be looks chafed and sore.

  ‘Finn,’ I say, and then stop myself. I want to tell him he needs to take a break, that he can’t do this to himself or he’ll cause long term damage. But he knows that already. ‘Keep it off tonight,’ I say instead.

  ‘I know,’ Finn says tightly, working out the muscles with a wince. ‘It’s my hand.’

  ‘You know,’ Tom says, ‘Bauman just signed off on new biomech for veterans. There unveiling them in a couple of days. I saw it in the newspaper - they’re making a whole evening of it at his residence in Top. Apparently they use chemetal.’

  Finn perks up immediately. ‘I know,’ he says, straightening. ‘A customer was talking about it today at the shop. Apparently it’s in the sensors - somehow they got it to work with linking the nerve cells. No idea how though. That’s Bauman for you.’

  ‘Bauman?’ I ask.

  From the looks I get in return, apparently this is something I should have known.

  ‘The Head Scientist?’ Finn says flatly. ‘Dean of the University?’

  ‘Ah,’ I say. ‘Him.’

  Finn snorts. ‘He’s a certified genius. Strongest Affinity of anyone, ever, but he stopped designing years ago. This is his first unveiling in about seven years.’

  ‘I heard it’s because his niece got wounded,’ Tom says. ‘In the attack last year. You know, when they came before the sun had set?’

  He’s talking about what happened in Hendy, a district on the South side of Under. There was a terrible storm one night and a huge chunk of the wall crumbled. They sent out the Patchers and a regiment to supervise, thinking they could at least block some of it up before the sun set.

  For the first time in record, the Katerakts came early. Nobody was expecting it - prior to that we thought they were strictly nocturnal. But hundreds of them turned up and ripped through soldiers and workers alike, started grabbing people in their homes and ripping them apart. The council had panicked, thinking there was a chance they might get through to Mid, and sent another regiment out. By that point it was already a blood bath, and then Katerakts were in a feeding frenzy. Most of the soldiers who were sent out never came back. After that, criminals were offered a choice: the Pits or signing up to fight. Most chose the Pits.

  Finn looks morose again. I clear my throat and shove the battery I got shot at for onto the table. ‘What do you think this is? I found it in the street.’

  Finn puts his drink town and glances over with interest. Then his eyebrows crumple with confusion. He picks it up, squinting.

  ‘Well,’ I ask. ‘Can you use it?’

  He looks at me. ‘Addie,’ he says slowly. ‘Did you take this from a public clock?’

  ‘No,’ I say. How could he possibly know that?

  ‘Yes you did,’ Finn says. ‘It’s a huge pace keeper. The only thing these are used for are clocks.’

  ’I wouldn’t say it’s huge.’

  ‘For a pace keeper it is. Were you in Mid again?’ He’s no longer looking wistful and sad. Now he looks angry and sad. I suppose it’s an improvement.

  ‘I was near the wall,’ I lie. ‘And it was there in the street. Maybe it fell.’

  Finn gives me an incredulous look but a commotion from the bar halts his reply.

  Thesp is splayed out over the wooden counter top, moaning into his own palm. ‘Go on,’ he’s saying. ‘Little shot of shine for your favourite customer!’

  Big Jay slams a tankard of water in front of him. ‘There you are.’

  Thesp groans, other hand scrabbling across the wood. He’s barely holding himself up. ‘Fuckin… this place isn’t the same. Flippers setting up shop, some fucking Topsider…’

  I look back at Tom who is glaring at Thesp. They don’t like each other. Tom gets prickly about being called a Topsider, and Thesp gets prickly about being called a—

  ‘Someone should cut the drunkard off,’ Tom says in a sharp, loud voice.

  I exchange a glance with Finn. ‘I’ll go,’ I say, but it’s too late. Tom’s voice has carried, and now Thesp is looking right at us, face coiling into a sneer. I get up out of my seat but he’s already staggering over.

  ‘Addie! Finn! You’ll have a drink with me, won’t you? Like we used to?’

  When we were younger, Thesp taught us to read. He had a strict system of payment: one shot of shine for every page. We usually only made it thirty minutes at a time before he was slurring too much to understand.

  I meet him halfway across the floor and tug him back to the bar. He’s an old sack of bones, weighs even less than I do. ‘Come on,’ I say. ‘Drink your water.’

  ‘Don’t want it,’ he sniffs, but dutifully gets settled at the bar stool. Big Jay mouths thanks over his head. ‘They put stuff in it, y’know,’ he slurs. ‘That’s why them lot are always coughing.’ A mottled white finger sways, then points to the miners in the corner. They don’t look particularly impressed.

  ‘Come on, Thesp,’ I say, pulling his tankard closer to his mouth.

  He takes a big gulp, then stiffens and spits it out all over me. I stand there, gritting my teeth as my shirt goes wet and clinging. It drips onto the floor.

  Thesp takes one look at my face and starts to cackle.

  Big Jay clicks her tongue. ‘Oh no you don’t,’ she says, setting down her rag. In a moment she’s hopped over the bar and grabbed hold of Thesp’s old shoulders. ‘Out you go. You’ve had enough.’

  Thesp grumbles but there’s no shape to the words. He’s too drunk. Big Jay wouldn’t have let him get in this state - he must have staggered in from somewhere else.

  A hand on my shoulder. ‘Are you alright?’ Finn asks, taking in my soaked shirt.

  ‘Fine. It was just water.’ I allow him to tug me back to the table. The door trills as Big Jay heaves Thesp out. For such a slight woman, she’s good at that. Lots of practice, I guess. Can’t be easy to run a pub in a place like this. Gotta get good at dealing with drunkards.

  The next surprise of the night is that Finn gets drunk. He didn’t have time to take a lunch break, as we find out a few drinks later. He’s a lightweight anyway, all knobbly knees and elbows, with a high metabolism. And he’s stressed. As Tom and I drag him out of The Old Boat, propping him up on either side, he’s mumbling about Rodger and radios. Big Jay gives us a sad smile as we head out.

  Dragging a woozy seventeen year old through a tunnel made of broken rocks is exactly as difficult as it sounds. Finn’s nose is pressed into my neck, his breath warm and wet. ‘M’broken,’ he slurs. ‘Tha’s why.’

  ‘Yeah yeah,’ I say, my jaw tight. Fucking Rodger.

  ‘You know,’ Tom says as we emerge out into the rooftops. ‘That biomech I was talking about. The prosthetics.’

  ‘What about them?’

  ‘You like stealing things.’

  I stop in place and give him a flat look. ‘I also like being alive.’

  Tom tugs Finn forward, and I have to follow to keep him stable. ‘If you can get into Mid, you can get into Top. If anyone can do it, it’s you.’

  My cheeks threaten at warmth. I ignore it. ‘Thanks?’

  ‘I’m serious.’

  ‘There’s a bit of a difference between pickpocketing the markets and getting into a biomech unveiling, wherever the hell that’s going to be.’

  ‘In his house,’ Tom says calmly. ‘It’ll be in his house, in the evening, two days from now.’

  ‘How do you know that?’

  ‘I told you, it was in the newspaper. And if the event’s in the evening, he’ll have to have the biomech in his house that day too.’

  Finn lets out a stream of mumbles and we both go quiet. The night is silent, which puts me on edge. The Katerakts don’t have voices. They don’t make any sound. That’s part of what’s so terrifying about them - you’ll never hear them coming.

  ’The tech will trickle down,’ I say with a confidence I don’t feel. ‘If everyone’s using it then we’ll get knock-offs soon, and then Finn can figure it out.’

  ‘That’ll take years,’ Tom says.

  ’So it takes years.’ I’m starting to get irritated. ‘What can we do?’

  With a grunt, Tom takes all of Finn’s weight for a moment as he stumbles. He doesn’t reply.

  The Den’s a mess when we get back. It’s always a mess: six rooms on the top floor of a long-abandoned mansion, close enough to the Pits that it’s probably bad for our lungs, but good in the sense that we’re not going to get cornered by the gangs. The streaky walls are covered with my childhood graffiti and the vast paper wings of Finn’s schematics that he pins up wherever he pleases. Only two of the rooms have proper wooden floors, although they’re so battered and scratched they barely look like wood anymore. It’s cluttered with the mismatched second-hand furniture we’ve hauled up over the years, and the shelves are stuffed with the kind of junk that someone with an Affinity ends up accumulating: bowls of tarnished silver cogs, tangles of wiring, half deconstructed engines and boxes and screwdrivers.

  We first found it years ago, back when we were living in the Dorms, and originally used it as a hiding place to escape the Mothers and their chores. Over the years we cleaned it up and bought in the furniture, and when Finn got the job with Rodger we moved in properly.

  There’s not much electricity in Under, so Finn made us our own lanterns, little bluish-green lights strung up along the walls. The whole room glows when I switch them on, like we’re suddenly underwater.

  We get Finn into bed, almost tripping over the debris of a half-finished something on his floor, and then Tom wanders off for a smoke on the rooftop. I’m left sitting on the battered sofa in the largest room, staring out the window. Darkness and my own ghostly reflection.

  I look down at my left hand, at the thumb and four fingers there: a full set. There’s a nasty black bruise on the nail bed of my left thumb from when I hit it off a wall during a trip to Mid last week. Each finger slots easily together as I flex and curl them into a tight fist.

  I think about biomech.