Busan’s outer districts had been burning for so long that most of the fires were out. Ash collected in the seams of the road and lifted around Onyx’s boots as he crossed what remained of a university district, passing shuttered cafés, collapsed walkways and the blackened frames of buildings whose signs still promised lessons, drinks, repairs, rooms to rent. Half a school had come down across the street ahead. Rubble had been dragged aside to make a path through it, and his targeting overlay picked out the route before he consciously looked for one.
As he walked, his body made the necessary adjustments: tendons tightening to compensate for broken ground, the servos in his right arm correcting against the weight of his rifle. Along the lower edge of his visor, diagnostics moved through their usual rotation.
MUSCLE TENSION: 72%
TARGETING MATRIX: STABLE
HEART RATE: 41 BPM
A small maintenance marker appeared beneath the last reading, noting the age of one of his original interfaces.
INITIAL INSTALLATION: AGE 15
Onyx dismissed it, but found his mind catching on the age anyway. Fifteen. A long time ago; so long that he could barely remember what his body felt like before NuYu started replacing parts of it with better versions. He remembered Daegu more easily: winter coming through the window frames, power disappearing before dark, his fingers too cold to hold a pen properly. Hunger had been harder to ignore, the ache returning no matter how carefully he rationed what little food there was, but eventually even that became ordinary.
When NuYu offered him a bed, regular meals and a door that locked from the inside, he said yes without thinking about it.
The rest came afterwards.
His right arm gave a quiet mechanical whir as it recalibrated, and Onyx flexed his fingers once to check the response. Clean and immediate, as expected.
“Area Z-3 remains unsecured,” a voice said over his comm. “Maintain sweep pattern and clear suspected broadcast nodes. No local comms. No hesitation.”
The two soldiers behind him separated without being told, one moving towards the ruined storefronts while the other covered the road. Onyx knew them as 013Y-G and 008D-T. That was enough. Names served little purpose in units where people disappeared between deployments and replacements arrived before anyone asked where they’d gone.
Sweeping the buildings ahead, he found no movement.
A torn poster moved instead, lifting from a wall whenever the wind caught beneath it. Most of the image had burned away, leaving half a face smiling beside three Korean characters Onyx couldn’t make into a complete word. He stared at it for a second longer than the sweep required.
Then he moved on.
That had been happening more often lately. Not enough to affect his metrics or for a handler to notice. A second spent looking at a poster, an unnecessary glance through an open doorway, the occasional thought about who had previously owned a room before an operation emptied it. None of those things interfered with the work, which meant there was no practical reason to report it.
Up ahead, the remains of an administration building blocked most of the road. Their intelligence placed the broadcast node under it, probably connected to one of the local resistance networks that kept rebuilding whenever NuYu cleared them out. Onyx signalled the others forward.
The entrance gave under his shoulder. Dust rolled through the lobby, disturbed after however long it had been lying there, and his filters compensated before he could smell much of it. Behind a broken reception desk, an entire wall had been torn open to expose a stairwell leading below ground.
“Move in,” the voice in his ear instructed. “No warnings. Clear the relay.”
Onyx raised two fingers and took point.
The narrow stairs forced them into single file. Emergency panels blinked weakly along the walls, illuminating layers of graffiti whenever they came back to life: names painted over slogans, slogans painted over symbols, dates, insults, declarations, crude drawings. Near the bottom, below most of the writing, somebody had pressed a small hand into blue paint and left the print on the concrete, fingers splayed.
Onyx spotted it.
There was absolutely no reason why, three steps later, he was still thinking about it.
Stopping at the bottom of the stairs, he raised a fist, and both soldiers halted behind him.
For a while there was only the intermittent click of failing equipment deeper in the building. Onyx let his audio implants separate the noises automatically, stripping away electrical interference, the ventilation system and the movement of the two men at his back.
But then — there.
Tap-tap. Tap. Tap-tap. Tap.
Onyx listened, trying to work out what it was. The pattern came again, its uneven rhythm initially classified by his system as environmental noise, but Onyx overrode the classification. It was too deliberate, changing a little each time it repeated.
Tap-tap. Tap. Tap-tap. Tap.
With a quick signal to the soldiers behind, they began moving towards it.
The hallway opened into what had been a server room. Most of the racks were melted where they stood, their frames bowed into each other, while cables coiled in heaps on the floor. Onyx scanned left, right, overhead, then stopped.
A boy sat on the ground in the far corner.
Ten, perhaps. Twelve at most. He was cross-legged on the floor with a portable interface balanced on one knee, wires running from it into a speaker assembled from scrap casing and a scavenged coil battery.
As Onyx watched, the boy tapped his fingers against his own thigh.
Tap-tap. Tap. Tap-tap. Tap.
His head was bowed over the interface, lips moving with the rhythm.
“Signal’s dead, but I still spit fire.
They took our mic, not our choir.
Glitch in the grid, we wire it back—
I’m just a spark, but I’ve got the track.”
Onyx stared. The boy hadn’t noticed them yet, not the three armed soldiers who’d entered the room behind him; he was too busy adjusting one of the controls on his little interface, tapping the rhythm when the speaker crackled, trying to make the next line fit.
Onyx’s rifle came up before he made the choice to lift it. His body knew the movement: shoulder, elbow, wrist; weight redistributed through his legs and hips while targeting data crossed his vision and fixed itself over the boy’s back.
SUSPECTED SYMPATHISER
UNAUTHORISED BROADCAST ACTIVE
ENGAGEMENT: AUTHORISED
His finger found the trigger, too.
But he stopped.
The boy tapped his thigh. Tap-tap. Tap. Tap-tap. Tap.
And Onyx just stood there, waiting for his hand to finish what it had begun. Only it didn’t. His fingers wouldn’t move. A tiny correction passed through his wrist as the weapon compensated for movement he hadn’t noticed making. The barrel returned obediently to centre mass. Distance, angle and predicted impact appeared beside the target marker.
All clean.
All correct.
But he still didn’t fire.
One of the soldiers behind him drew a quiet breath.
Onyx could feel his finger on the trigger now, the pressure needed to complete the movement absurdly familiar. After all, he had done this at greater distances, under worse conditions, against targets moving fast enough that hesitation meant losing them. This should’ve been easier.
The boy wasn’t even aware of them.
Tap-tap. Tap. Tap-tap. Tap.
And Onyx thought suddenly about cold hands in the dark — not the boy’s, but his own. A room in Daegu with the power out again, winter pushing through newspaper stuffed around the window frame. Somebody smaller than him was making up terrible verses nearby, refusing to stop even when Onyx told him he was going to throw a shoe at him if he rhymed cold with old one more time.
His heartbeat thudded so hard he could feel it in his throat, and he blinked. The target marker remained fixed on the boy, but his hands had started to tremble; his arm tried to correct for it.
And then, to his right, 008D-T moved.
The motion barely entered Onyx’s peripheral vision before the other rifle came up.
The boy kept singing.
“They cut the feed, said ‘drop the sound,’
I loop it back from—”
The shot cracked through the room.
Onyx watched as the boy folded over the interface, going gently, slowly down.
For half a second the speaker continued without him, letting out a high electronic whine before the damaged loop caught and dragged the same sound back through itself. The boy’s hand slipped from his thigh and struck the concrete, and then stayed there, unmoving.
The target marker in Onyx’s vision vanished.
008D-T lowered his weapon and turned towards the next row of server racks before the body had finished falling.
FUNCTION: STABLE
MISSION STATUS: SUCCESSFUL
EMOTIONAL RESPONSE: WITHIN PARAMETERS
The speaker clicked, but Onyx didn’t move. Instead, he stared at the boy’s hand, small and pale against the grey-dark of the room.
Move. He knew he had to move. There were still rooms to clear, exits to secure, equipment to destroy. His body understood all of that, but his legs refused to cooperate.
Heat simmered behind his eyes, and his balance systems corrected once, twice, registering a change it couldn’t understand. Planting his boots more firmly, Onyx waited for the floor to become level again.
“Hey.”
A voice at his left shoulder.
013Y-G stood a few metres away. The man had already lowered his rifle and was looking directly at him through his visor.
Hey. That wasn’t Onyx’s designation, and it didn’t sound like an instruction, either. Barely even a word worth noticing, except Onyx couldn’t remember the last time one of them had addressed him like that.
013Y-G tipped his head towards the corridor.
Onyx understood, and forced his legs to finally move.
The speaker clicked behind him as they left the room. He could still hear it halfway up the stairs, one damaged piece of the boy’s track repeating into the empty space below.
Tap—
At the top, Onyx glanced back.
013Y-G saw him do it and their eyes met briefly.
Neither of them said anything.
Outside, Busan was the same as it had before they went underground. Ash moved across the road. The ruined poster lifted in the wind. His diagnostics continued their rotation in the corner of his vision, finding nothing wrong with him.
Onyx dismissed them one by one and followed the others back towards transport.
He didn’t report 013Y-G for speaking out of protocol.
013Y-G didn’t report that Onyx had failed to fire.
~*~
The transport took them back through Busan without conversation. That much was normal.
Onyx sat with his rifle secured between his knees and watched the mission report assemble itself across his visor. Confirmed targets. Ammunition expenditure. Structural damage. Casualties. The numbers arranged into orderly columns as the truck rocked beneath him, reducing the last few hours to data that could be filed and compared and forgotten.
He dismissed the report.
Across from him, 008D-T sat motionless with his visor down. Beside him, 013Y-G had taken the seat nearest the rear doors. Neither man looked at Onyx, and Onyx didn’t look directly at them, either.
The engine vibrated through the floor and into his boots. Usually he liked that. There was a predictability to machinery in motion, hundreds of working parts producing one continuous result, and if he concentrated, he could follow the vibration through his legs and up into his spine.
But tonight, another rhythm kept getting in the way.
Tap-tap. Tap. Tap-tap. Tap.
Onyx pressed his heels harder to the floor, letting the engine swallow the memory for a few seconds, but then it came back anyway.
He gave up trying to block it out.
By the time they reached base, Onyx had prepared himself for processing to catch what the mission hadn’t. His weapon would be checked and his combat log reviewed, response times compared against a baseline. Somewhere in all that data, there had to be a record of the seconds he’d spent standing in that server room with his finger resting uselessly on a trigger.
Standing nearby, he watched as his rifle passed inspection, his combat log returning without comment. The first diagnostic sweep found no meaningful deviation, and the second agreed with it.
What did that mean?
EMOTIONAL BASELINE: WITHIN PARAMETERS
COMBAT READINESS: CONFIRMED
Onyx read the results twice, and for a brief, stupid moment, he wondered whether the hesitation had only felt as long as it had because he’d been inside it. Perhaps the delay had been negligible. A fraction of a second exaggerated by adrenaline and memory.
Then he remembered 013Y-G watching him at the top of the stairs.
No.
Someone had seen.
Later, Onyx sat alone in the diagnostics bay in regulation base clothes, his armour folded on the bench beside him and his boots tucked underneath. The recalibration console worked through his post-mission maintenance while he leaned forward with his forearms braced against its edge. UV light travelled slowly over the exposed interfaces in his right arm, checking seals and minor damage while coolant cycled through joints that had run hot during the operation.
Everything worked, and that somehow bothered him more than it should’ve.
When the door opened behind him, Onyx knew who it was before he turned. 013Y-G’s armour made a soft mechanical complaint at the left knee whenever he put his weight on it, quiet enough that Onyx had probably been hearing it for months without realising it.
“You froze.”
Onyx turned towards him.
013Y-G’s visor was up. Without it, he looked older than Onyx expected, pale and tired around the eyes, with a thin scar disappearing into his hairline. Onyx couldn’t remember ever seeing his face this clearly before.
There was no point denying it. “Yes.”
“I logged it as signal lag,” 013Y-G said.
Onyx stared at him for a moment. “Why?”
“Doesn’t matter.”
“It matters to me,” Onyx said, turning more fully towards him now.
The corners of the man’s mouth pinched, but Onyx didn’t think it was amusement.
“If anyone asks, you experienced temporary interference with your targeting interface. It lasted less than two seconds and corrected without intervention.”
Onyx glanced towards the diagnostic display. “I didn’t, though.”
“I know.”
“You falsified the report?”
013Y-G didn’t move, but Onyx caught a quiet sigh, and remembered the way the man had said hey in Busan, so unfamiliar and yet oddly specific in that moment. Like a signal. One Onyx still didn’t fully understand.
“Why?” Onyx asked again, a little firmer this time.
013Y-G blew out a breath through his nose and glanced briefly towards the door. “You think you’re the first?” he said, stepping closer and lowering his voice. “You think nobody else ever looked at an order and wondered what the hell they were doing?”
Onyx had no answer for that. For years, the people around him moved when instructed, fired when authorised, slept when scheduled and disappeared when reassigned. He never asked what any of them thought about it. He wasn’t sure it had ever occurred to him that there was anything to ask.
013Y-G tapped two fingers on the edge of the recalibration console. “Signal lag,” he repeated. “Remember that.” Then he turned towards the door.
“013Y-G.”
The man stopped.
Onyx meant to say thank you. The words reached the point of becoming sound, sitting there on his tongue, but they went no further than that.
After a second, 013Y-G turned back to him.
All Onyx could think to do was nod his head once.
The man returned it, and then he left, closing the door behind him.
Onyx stayed where he was with his hands resting against the console as the diagnostics display refreshed.
EMOTIONAL BASELINE: WITHIN PARAMETERS.
The display said he was within parameters. Onyx watched the readout for a long time; it didn’t change.
Finally, he reached up and switched the display off.
And in the sudden dark, the rhythm came back.
Tap-tap. Tap. Tap-tap. Tap.
~*~
At 03:17, Onyx reached the junction between the diagnostics wing and the barracks, and that was where he stopped.
There was no real reason to stop; his post-mission cycle was complete, his equipment was secured and the next instruction on his schedule was six hours of rest before morning readiness checks. He took this route so often that he barely needed to think about where he was going. Right led towards the barracks. Left led deeper into the service levels, then towards vehicle access and the eastern perimeter.
Onyx looked right, then left.
You think you’re the first?
He stood there long enough for the overhead strip light to blink twice before steadying.
Then he turned left.
Onyx made it halfway along the corridor before that became stranger than an alarm would have been. All of his access remained active; no warnings appeared across his visor. Nobody demanded an explanation for his route, and when he walked past a wall scanner, it recognised him, verified his clearance and let him continue.
He almost stopped again and turned back.
Almost.
Tap-tap. Tap. Tap-tap. Tap.
Instead, he kept walking.
At the next junction, he took another corridor that didn’t lead towards the barracks. After that came a service stairwell, then a maintenance passage running behind the vehicle bays. Every choice felt enormous for roughly three seconds before becoming nothing more than the direction his feet were already taking him. And because this hadn’t exactly been a conscious choice, he didn’t have anything with him, no bag, no spare clothes, no food or money or civilian ID. The few personal things he did own were still in his assigned locker, although when he tried to picture them, he couldn’t think of anything worth going back for.
After a while, he picked up his pace a little. Night staff crossed between departments nearby, and cleaning units moved along their programmed routes. Below, machinery started up with a heavy mechanical shudder. Onyx knew where the cameras couldn’t quite see, which doors took longer to close than their specifications allowed and which patrol drone regularly returned to its charging dock with eleven per cent power remaining because one of its cells was failing.
Tonight, he was grateful for that knowledge.
Pausing, he waited until the drone crossed the far end of the hallway and disappeared along its scheduled route before moving on.
Only when the first security door opened for him did fear arrive properly.
The scanner read his credentials and a green indicator appeared. Locks disengaged one after another inside the door with a series of heavy clicks. NuYu still knew who he was. More importantly, it still thought it knew what he was doing.
Onyx stepped through, the door closing behind him.
By the time he reached the outer service yard, he knew he wasn’t going back. The decision didn’t come to him in any dramatic way, no sudden certainty or clean dividing line between soldier and deserter. He just glanced back at the building behind him and understood that returning would mean choosing to return.
And he couldn’t.
When he left the covered walkway, cold air slapped him in the face. Beyond the yard, the perimeter separated the compound from a freight district that ran almost continuously to the coast. Onyx knew the security layout, the timing of the patrols, the range of the ground sensors and the section of perimeter fencing scheduled for replacement because its detection grid failed intermittently in freezing weather.
His body knew the rest.
Crossing between patrol sweeps, he waited under a loading platform while a drone passed overhead, then climbed the service frame beside the damaged section of fencing, using his right arm to take most of his weight. His boots found the narrow joints automatically, and training carried him over the perimeter NuYu trained him to defend.
On the other side, Onyx dropped onto frozen mud, staying crouched for a moment and listening for an alarm or voice in his ear.
Still nothing.
After that, he rose and walked away.
The freight yard beyond the compound was already awake. Hauliers moved between loading bays while cargo trains waited beneath gantries, some taking machinery inland, others marked for ports and reconstruction zones. Workers crossed between them with their heads down against the cold. Nobody paid much attention to one more man moving with purpose.
Onyx chose north-east. It seemed as good as any direction other than the one he’d just come from.
At the far end of the depot, he found a freight train carrying stripped machinery and obsolete industrial parts towards the coast, its route continuing into the northern freight network from there. Good enough. Onyx wedged himself into the maintenance space beneath the rear carriage, cramped, filthy and so loud he had to adjust his audio sensitivity manually.
When the train finally moved, Onyx expected pursuit. For the first few hours, he checked repeatedly for signs of it, until the gaps between checks began to grow longer.
Stations came and went, all nameless and all the same. Whenever he found a maintenance tap, he drank from it. He slept in intervals too short to feel like real sleep. And through it all, his body rationed energy automatically, suppressing hunger before it became a problem. That irritated him. Apparently NuYu was useful even when he was on the run from it.
The thought almost made him laugh.
Somewhere north of the Korean Peninsula, the freight route joined one of the old subsea lines towards the Russian coast. Onyx felt the change before he saw any indication of it: pressure altering around the carriage, the sound of the wheels becoming enclosed and enormous as the train descended.
Reaching into the maintenance pouch still clipped at his waist, he pulled out the diagnostic kit. It was NuYu property. So had he been, up until a few hours ago; now, he didn’t know what he was anymore. Onyx turned the kit over in his hands. Regulations meant he had to carry it at all times. The device could access field systems, restore damaged interfaces and, under the right clearance, erase compromised operational data.
But Onyx knew another use for it, too.
Connecting the kit to the access point at his wrist, he opened the menu and navigated past maintenance, diagnostics and recovery until he reached administrative controls. The wipe protocol was behind two confirmation screens and a warning informing him the process couldn’t be reversed without central authorisation.
He paused, hovering his thumb over the control.
But Busan returned immediately. A boy tapping a rhythm on his leg. 013Y-G staring at him across the diagnostics bay. You think you’re the first?
Onyx pressed confirm, and his vision swam with warnings.
Service credentials disappeared first, then unit assignment, followed by operational permissions, location history and the identification handshake that allowed NuYu to recognise him automatically. Errors multiplied as connected processes searched for information that no longer existed.
For a few seconds, his visor became almost unusable.
And then the warnings vanished.
IDENTITY: NULL
AFFILIATION: UNREGISTERED
TRACE PATH: CORRUPTED
Onyx waited, but nothing replaced them. He stared at the empty display where his unit designation normally sat. Then the train emerged from the tunnel and pale morning light flashed between the gaps in the carriage. Disconnecting the kit, he looked down at his hands. For the first time since he was fifteen, NuYu didn’t know where he was.
Admittedly, neither did he.
Off-grid seemed like the best option for now, or at least as off-grid as someone like him could get.
He had a horrible feeling it wasn’t going to be that easy to disappear completely. NuYu spent years installing hardware throughout his body, and right now he had no way of knowing how much of it could still lead them back to him.
The farther west he travelled, the harder his body became to manage. Systems designed around regular maintenance complained first, giving him delays in sensory feedback, small timing errors in his right arm, stabilisers compensating half a second later than they should. None of it stopped him, but it all got added to the growing list of things that needed attention.
Near Bratislava, that list became too long to ignore.
Onyx found shelter in a run-down hostel near the freight district, the sort of place where nobody asked why a stranger’s ID returned nothing. People slept in converted offices and old storage rooms on makeshift bunks. Two biohackers were working over an open rig at a table near the kitchen, while a woman sorted salvaged components into plastic trays.
Onyx stood just inside the entrance, wet, exhausted and increasingly aware that one of his knee stabilisers was misfiring.
Nobody reached for a weapon, which took a little getting used to, though a man at the table looked him over, then pointed towards an empty chair.
“You paying?” he asked.
Onyx checked his pockets despite already knowing the answer. “No.”
The man glanced at his arm.
Twenty minutes later, he sat with his sleeve rolled up while one of the biohackers removed a length of redundant relay wiring from an old secondary interface. It hurt a lot more than Onyx was expecting, but he said nothing.
“You can swear, you know,” the biohacker said.
Onyx considered that for a second, then said, “Fuck.”
The woman sorting the components laughed.
Still, he got two nights’ shelter for the wiring, plus someone handed him soup that ended up tasting like mushy cardboard. But it was hot, and it was filling. He sat on the edge of a narrow cot with the bowl warming both hands, staring down at greyish vegetables he couldn’t identify, and wondered if accepting it had just created an obligation that no one had explained to him.
Two days later, the woman handed a burner card to him just as he was getting ready to leave. It had a crude symbol scratched over its surface, a circle broken by uneven lines.
// NODE 6 — HOLD FAST //
Onyx turned the card over. “What is it?”
“A direction,” the woman said. “You look like maybe you need one.”
“There isn’t an address.”
“No.”
Onyx waited.
The woman shrugged. “You’ll work it out.”
He disliked that answer immediately, but he kept the card anyway.
~*~
The targeting assist locked onto a woman crossing the street, and Onyx froze as a thin marker tracked her across his vision. She had shopping bags in both hands, and nothing about her suggested a threat.
TARGET ACQUIRED.
All right, so that was going to be a problem.
Onyx shut the assist down manually, and the marker vanished.
Twenty minutes later, it happened again with a man getting off a tram, then with a teenager cutting across a road. Each time, Onyx disabled the system, and each time, it restarted itself.
“Shit,” he muttered.
Eventually, he found an empty service passage and sat with his back to the wall, pulling up every diagnostic he could still access. Most returned incomplete results. The admin wipe removed NuYu’s ability to identify him through the usual channels, but the hardware inside his body still ran processes designed for a soldier. Target acquisition. Threat response. Pain suppression. Behavioural safeguards.
Onyx frowned at the list. He had no idea which systems could still communicate externally, and that was the part he couldn’t stand — not knowing which part of himself would finally get him caught.
After another two days of searching, he found an old med station in a derelict apartment block. Its entrance was mostly buried under fallen masonry, but he managed to clear a gap and squeeze through into the murky darkness. Most of the equipment was gone, but whoever stripped the place left behind an old surgical torch, a scanner with some charge left and a handful of sealed instrument packs.
Onyx checked everything twice.
Then a third time just to be sure.
There were parts of his augmentations he knew he couldn’t touch. The primary interface at his spine handled too much sensory information; damaging it could leave him unable to control half his body. His right arm depended on several of the systems NuYu installed, as did the stabilisers that kept his movements coordinated. Those stayed.
The systems that gave NuYu access to him were different.
Telemetry.
Remote diagnostics.
Command permissions.
Plus the targeting system that spent the last two days trying to decide who he should kill.
Sitting on the edge of an examination table, he stared down at the scanner map. Maintaining his own body was second nature by now; NuYu had made sure of that, giving him enough knowledge to remain operational until proper technicians could reach him.
Nobody ever taught him how to remove hardware, so he’d have to work that part out himself.
Onyx lowered his head.
Tap-tap. Tap. Tap-tap. Tap.
Then he picked up the surgical torch.
The first incision hurt less than he expected. Pain suppression kicked in automatically, reducing the cut to pressure and heat while he opened the tissue around an old access point below his shoulder. Onyx almost laughed. Even now, NuYu was trying to make this easier for him. Locating the telemetry lead, he sliced through it, and feedback flashed white in front of his eyes. He waited for it to clear, breathing slowly through his nose, then checked the scanner. One connection was gone.
Good.
But there were many more.
Some components came free cleanly, but others were buried under years of scar tissue and reinforced mesh, installed with the assumption that nobody would ever need to remove them. Blood made the instruments slippery, and the surgical torch filled the room with the rank stench of cauterised tissue and heated polymer.
Onyx stopped twice to clean his hands.
The third time, he stopped because they were shaking too much. He tried to remember, but he couldn’t recall the last time his hands shook like that. Maybe not since he was a teenager.
Setting the instrument down, he leaned back and watched the doorway for a while, but no medic or technician appeared, no 013Y-G standing nearby with a lie ready for the report.
It was just him.
The thought frightened him enough that for an absurd moment he wanted the barracks back. He wanted somebody else to know what came next. He wanted a schedule telling him when to sleep and a diagnostic telling him whether he was functioning correctly.
But this was what he had chosen.
The remote-access module was deeper than the others, so close to his spinal interface that Onyx knew one mistake could do way more than just hurt. Focusing down, he worked on it slowly, following the scanner instead of trusting sensation. His pain filter compensated whenever he touched a nerve cluster, smoothing each warning before it properly reached him. Hm. That wouldn’t do. Onyx found the filter controls and stared at them for a long time before disabling NuYu’s access to those as well.
The pain came so violently that he dropped the instrument, folding forward with a sound he didn’t recognise as his own. For a while, he couldn’t do anything except try to stay conscious, his muscles locked, jaw clenched so hard his teeth hurt. Sweat dribbled down into his eyes; he blinked it away. Every place he had opened now burned with information his body spent years learning not to give him, and when he felt ready to pick up the instrument, his hand missed it the first time.
“Come on,” he muttered, and tried again.
After that, the details blurred. At one point, he found himself on the floor and stayed there until his vision cleared and his head stopped spinning.
By the time he sealed the last incision, blood covered the examination table and dried dark across both hands. A few warning indicators remained; his right arm responded late when he moved it, and one stabiliser had stopped reporting entirely.
But the external-access scan returned nothing, which meant NuYu could no longer reach him.
Weirdly, he didn’t feel triumphant. Exhaustion saw to that.
Onyx cleaned the instruments because leaving them covered in blood bothered him. Halfway through, he realised how ridiculous that was but continued anyway. Then he lowered himself onto the floor beside the table and closed his eyes.
Tap-tap. Tap. Tap-tap.
Onyx woke with his hand clamped around the wrist of someone who wasn’t there. It took him a long time to figure out where he was, his body throbbing with dull, hot pain.
“Right,” he said.
He managed to get to his feet after three attempts. The med station was worse in the daylight, although Onyx suspected most of it was his fault. Cleaning himself up as best he could, he packed the few medical supplies worth taking and checked his body again. His systems disagreed about whether he was fit to travel, not that he really needed them to tell him he was in bad shape.
West took him through more freight routes and service tunnels. He slept under stations and crossed cities without learning much about them, Vienna a blur of river smell and pale stone, red trams sliding past above him whenever his route brought him close enough to the surface. Berlin came later in rain and rust-dark brick, the Spree flashing silver between buildings and the old television tower appearing now and then above the rooftops like a landmark he had no use for.
Pain and exhaustion made every kilometre harder. Onyx adapted because adapting was better than stopping, although more than once he wondered if he’d made the right decision after all.
London appeared through low cloud and dirty morning light, towers rising beyond the port while drones moved between them. Onyx left the ship’s cargo hold with the dock workers and kept his head down.
// NODE 6 — HOLD FAST //
The directions hidden in the card took him away from the main transit network and through a series of service routes towards an entrance that looked like nobody used it anymore. Steps led down into darkness below. Onyx checked behind him, not really sure what he was expecting. Nobody was following.
Sliding the card back into his pocket, he made his way down into the waiting dark.
~*~
London felt older beneath the surface, wear layered into crumbling stone and rusted metal. The tunnels deepened beneath the old metro lines, splitting into narrower dug-out routes that doubled back on themselves, dust so thick that it preserved every footprint. Onyx moved slowly and steadily, his limp worsening whenever he spent too long on his feet. He noticed how much louder he was now, one foot landing heavier than the other and echoing off the walls, the occasional scrape when his balance corrected too late. It was taking some getting used to.
On the second day, he found a disused bunker between two maintenance shafts. The door still worked, which was good enough for him, and the metal stayed warmer here than it did in the surrounding tunnels. Whenever the ache in his spine became too much to ignore, he tried sleeping, only waking when footsteps or voices bled down from above.
Water was the easier problem. Onyx had seen people lugging filled containers through the upper tunnels, and following the route backwards led him to the Waterworks two levels up, where old filtration systems fed a collection of tanks and mismatched pipes. For a moment, Onyx considered turning around at the sight of the crowd, but nobody challenged him when he quietly joined the queue.
They stared, though.
There was no getting away from it. His arm was hard to miss, as was the interface running into the collar at the back of his shirt, and he was aware that very little about him encouraged strangers to assume harmless intentions. Still, the people ahead of him collected their water and left, and the people behind him waited. When his turn came, Onyx filled two salvaged containers, watched the person beside him to make sure there wasn’t a procedure he’d missed, then carried them back to the bunker.
Food took longer to solve.
He still had a little left from the journey west, but not enough to waste while he worked out what came next. He had no local currency and no intention of discovering how far goodwill extended when he had nothing to offer in return.
Equipment, however, was everywhere.
The deeper tunnels were full of old scanners and broadcast coils, cracked terminals, stripped circuit boards and components abandoned because nobody thought they were worth rescuing. Onyx brought anything useful back to the bunker and sorted it across the floor, although useful became more of a generous definition as the pile grew.
He fixed it anyway because it gave his hands focus while his body recovered.
It also gave him something to trade. He heard about the Ghostlines Exchange before he found it. Directions scratched onto walls and passed between strangers led him to a disused station where traders had taken over the platforms for the day, filling them with folding tables, crates, hanging lights and blankets spread directly across the floor.
The first visit was beyond uncomfortable. The market was crowded, and Onyx stood out in ways he couldn’t do much about. Heads turned when he passed, and more than a few conversations faded as he moved between the stalls.
Still, nobody stopped him.
That took longer to get used to than the staring.
Onyx didn’t stay any longer than he had to. A restored battery pack got him bread and dried fruit, and once the exchange was finished, he returned directly to the bunker.
Two days later, the station was empty.
Onyx stood on the abandoned platform for several seconds before noticing a newly chalked symbol near the stairs, along with directions to another section of the Lines where the market would appear next.
Before long, repaired equipment went with him whenever he found the Exchange: two working hand scanners for enough provisions to last a few days, a portable heater he’d coaxed back to life for a bag of vegetables that still had dirt clinging to the roots. The transactions were straightforward, at least. Nobody needed his history before agreeing on a price, and he didn’t have to offer more of himself than the object in his hands and the few words needed to barter.
With shelter, water and food covered, Onyx fell into small routines. Each morning he went to the Waterworks, then spent as much of the day as his leg allowed scavenging and learning the tunnels around him. He found a Scrap Garden tucked into a warmer pocket of the Ghost Lines where lamps glowed over trays of greenery and people fed soil that had no business surviving this far below ground. He learned which passages flooded after heavy rain, where abandoned electronics piled up and which routes eventually brought him back to the Waterworks, the Exchange or his bunker.
Gradually, the Ghost Lines became less of a confusing maze.
And then, one night, the floor started vibrating.
At first Onyx assumed it was failing machinery. Plenty of equipment still worked down here, most of it badly, and the vibration was too weak to bother investigating. He ignored it until it stopped.
But then the next day, it came back.
Four notes.
A pause.
Four notes again.
It wasn’t quite music. The timing slipped at the same place on nearly every repetition, one note a fraction too early before the rest caught up with it.
By the third day, Onyx was waiting for it.
He scanned around for a transmitter but found nothing nearby. Whoever was making the music was deeper in the tunnels, the walls reducing it to vibration and scraps of melody, and although Onyx could probably have followed the sound if he’d wanted to, he didn’t.
Over time, the pattern changed. The timing improved a little; another sound appeared underneath it, disappeared the following night, then returned altered. Onyx listened while he worked, some nights only for a few minutes, others until he forgot how the tunnels sounded without it. And if his foot occasionally kept time, nobody was there to comment on it.
Once, he thought he heard laughter between the beats, bright and sudden before the walls swallowed it.
Leaning his head against the wall, Onyx listened as the four notes started over, and for a little while, they were more distracting than the other rhythm — the one that had followed him all the way from Busan.
Tap-tap. Tap. Tap-tap.
As his leg improved, Onyx travelled farther. Curiosity took him down routes he hadn’t needed for water or food, past junctions he hadn’t yet mapped and into older sections where fewer people seemed to go. One of those routes brought him to a relay room tucked beyond an old data junction.
People still used this place; that much was obvious. Battered equipment had been dragged together into a functioning rig, cables running between systems that weren’t designed to speak to each other. Onyx stopped just inside the doorway and stared from one connection to the next, trying to understand how any of it worked. Whoever built it either knew exactly what they were doing or had been incredibly lucky, but he wasn’t sure which.
Messy words had been scraped through the grime on one wall.
They tried to erase us / So we rewrote the score.
The music he’d been hearing through the tunnels was playing from a speaker beside the rig.
Here, without walls and half a kilometre of tunnel between them, he could actually hear what it was doing. Those four notes were still underneath everything else, joined now by percussion and a low electronic line that almost pulled the whole thing together.
Almost.
Onyx stepped closer and crouched beside the rig, listening through one repetition and then another.
There.
The timing slipped in the same place.
He waited for the loop to come around again, paying closer attention this time, and there it was: one beat landing slightly early and pulling everything after it out of place.
“That’s been bothering him for days.”
Onyx was on his feet before the sentence finished, his weight already redistributed and one hand reaching automatically towards his hip. His fingers closed around fabric where a weapon used to be.
A man stood in the doorway, tall and lean, dressed in a worn jacket that had seen better years, white-blond hair falling around his face and catching muted traces of green and blue when he moved. Onyx glanced at the man’s hands, but they were open and loose at his sides, with no sign of a weapon.
Didn’t mean he wasn’t dangerous, though.
The man seemed to notice him assessing him, and he smiled. “Hello. I’m Soahn.”
Onyx said nothing.
Giving him plenty of space, Soahn stepped into the relay room and crossed towards the rig. “You’ve been down here a few days.”
Slowly, Onyx nodded, watching him as he went to the rig and adjusted a cable.
“We didn’t see any reason to bother you,” Soahn said. “But I could feel you moving through our network.”
Onyx’s gaze went automatically to the doorway, and he angled himself so that he was facing it but still had Soahn in front of him. “We?”
“Yes, me and my friends.” The track reached its end and looped back to the start, drawing Soahn’s attention back to the speaker. “You’ve been listening to this?”
Nodding again, Onyx said, “The timing’s wrong.”
For the first time since entering the room, Soahn didn’t seem to have a response. “Oh,” he finally said, then let out a soft laugh.
“What?”
“Nothing.” Soahn reached over and nudged one of the controls. “But I think somebody else should hear you say that.”
“Your friends?”
“Yes.” Soahn turned towards the corridor, but before he reached it, he glanced back. “You can stay, by the way. Nobody owns this part of the tunnels.”
Onyx frowned.
As Soahn stepped through the doorway, Onyx opened his mouth, thinking of at least a dozen questions he wanted to ask, though none of them came out. “Onyx,” he said instead.
Soahn paused, turned briefly, and then nodded. “Nice to meet you.”
Then he was gone.
Onyx listened until the footsteps faded beyond hearing, then turned slowly towards the rig. The music was still playing, unconcerned by any of this, and before long the same beat landed slightly too early and pulled the rest after it.
He frowned at the speaker.
~*~
A few days after meeting Soahn, he returned to the relay room and found it empty. The track was still playing quietly through the speaker, those same four notes now buried under more layers of instruments. Onyx listened while he checked over the equipment, trying not to pay attention to the transition that had been bothering him for days.
It came around again, still wrong.
Onyx glanced towards the doorway, then back at the synthboard. One small adjustment would probably be enough to fix it. Surely Soahn and the other guy knew that, but for whatever reason, they hadn’t bothered.
Annoying.
Without thinking too hard about it, he stepped closer and changed an input, then waited for the loop to restart. It played smoothly, this time without catching.
Better.
Onyx left it that way.
The following afternoon, the music started while he was repairing an old scanner in the bunker. Pausing, he listened for the section he’d changed; it played without fault. The corner of his mouth twitched.
Two days later, a sealed ration pack appeared outside his door.
The next morning, he found a coil of intact cable beside it, exactly the gauge he needed for a relay patch he’d been piecing together.
Onyx stared at that one for a while.
Apparently somebody was paying attention.
That evening, unfamiliar footsteps approached the bunker. They weren’t Soahn’s; these were quicker and considerably less careful, broken once by a boot catching against uneven flooring, a muttered curse and the unmistakable clatter of something metallic hitting the ground. A cable scraped along the floor outside, and another curse followed.
Onyx was already on his feet when a man appeared at the threshold.
“Well, damn.” The man stopped when he saw Onyx, apparently unconcerned by the fact that Onyx was considerably larger than him and currently staring. “Soahn wasn’t kidding. You are real.”
Though Onyx had never seen him before, he recognised the voice: the laughter from a few days ago.
The man stepped farther into the room, dragging the offending cable behind him. An oversized jacket hung from his frame, patched and worn thin in places, while battered headphones rested around his neck as naturally as if they belonged there. His gaze travelled openly around the bunker, taking in the salvaged equipment, the repaired terminals and the bedroll in one corner.
Then he grinned. “This tracks.”
Onyx frowned. “What does?”
“You.” The stranger gestured vaguely around them. “Soahn said you’d been fixing half the dead tech down here.”
“Not half.”
“More than half, then?”
It was hard to tell if he was joking, so Onyx said nothing and frowned at him.
Seeming unbothered, the man dropped into one of the rusted chairs Onyx had dragged from another room and indicated the scanner in his hand.
“Plus, you’ve been messing with our track.”
“I changed one input,” Onyx pointed out.
“Yeah. And it was better.” The man leaned back in the chair, apparently satisfied with a conversation that had taken place entirely through a synthboard. “You like it?”
Onyx considered the question. “It was honest.”
The reaction was immediate: the man’s whole face brightened. “Yeah?”
Onyx nodded.
“That one’s mostly Rayne’s. I just helped it find its feet.”
Rayne. Another name with no useful context attached to it.
The man’s hand dropped to his thigh, fingers moving absently while the silence stretched.
Tap-tap. Tap. Tap-tap.
Onyx froze. Busan opened beneath him for half a second: a boy sitting on the floor, fingers keeping time on his leg, the rifle heavy in Onyx’s hands.
But the gunshot didn’t come.
Tap-tap. Tap. Tap-tap.
The man noticed his silence and stopped. “You okay?”
Onyx nodded, because he couldn’t think of what else to do.
“I’m Kairo, by the way.”
“Onyx.”
“Yeah, Soahn said.” Kairo looked around the bunker again, his attention catching on the bedroll. “You waiting on someone?”
“No.”
“Good.” Kairo nodded, as though this confirmed something. “Then you should stay.”
There was no caution in Kairo’s expression and, as far as Onyx could tell, no calculation either. He just seemed to mean it.
Stay.
Onyx scanned around the bunker, at the equipment he’d repaired so he could buy more supplies later, at the scanner still held in his hands, at the dust and grime and damp walls. Somewhere beyond the tunnel outside was a relay room containing one small change he’d made to somebody else’s music, discovered and kept.
And then there was Kairo, sitting casually in his chair as though inviting Onyx to stay in his own bunker made total sense.
Onyx nodded.
Kairo’s grin returned immediately. “Cool. We’ve got space. Just don’t mess with Soahn’s tea stash. He’ll know. Don’t ask me how; he just will. Guy’s really weird about tea.” Getting to his feet, Kairo gathered up the cable and headed towards the door. “Well, see you.”
Onyx watched him leave.
A few seconds later, something metallic clattered to the floor farther down the corridor.
“I’m fine!” Kairo shouted.
Onyx hadn’t asked.
But for the first time in months, possibly years, he laughed.
~*~
There came a point where Onyx realised he was spending more time in the relay room than he was in his own bunker, though he didn’t comment on it, and neither did anyone else.
Kairo was usually there first, surrounded by enough loose wiring to be an electrical hazard. Tonight, a few coils were looped around one arm like mismatched bracelets, while a synthpad balanced on one of his knees, wobbling precariously whenever he moved. He muttered as he worked, little pieces of rhythm escaping under his breath while he built one layer, abandoned another and then went back three steps to change something he apparently liked five minutes ago.
It was an odd way of working, and Onyx had given up trying to understand Kairo’s process.
The results were usually good, though.
Nearby, Soahn sat with his back against one of the old supports, repairing a component Onyx didn’t recognise. The soldering iron flashed blue on the metal as he worked, willing to spend twenty minutes on a single connection to make sure it was correct.
Rayne was at the far end of the room, leaning against the wall, head lowered slightly, listening. Onyx still didn’t know what to make of Rayne. He wasn’t human, and seemed perfectly comfortable sitting or standing quietly for long stretches without feeling the need to fill them. Tonight, he listened to the music, only looking up when Kairo changed a layer on the track.
A scorched console module was open on the floor in front of Onyx. Nobody asked him to repair it, but one of the internal connections failed whenever the casing got warm, and leaving it that way had started to irritate him. He was most of the way through replacing the damaged section when Kairo swore.
“It’s wrong.” Kairo replayed the same section. “Nope. Still fucking wrong.”
“Yes,” Rayne said.
Kairo threw him a glance. “Thank you, Rayne.”
“You sounded uncertain.”
“I wasn’t.”
“You said it twice.”
“That was emphasis.”
Onyx glanced up in time to see Soahn smile at whatever he was soldering.
Dragging both hands down his face, Kairo let out a sigh. “It isn’t syncing. I’ve tried everything. It’s clean, everything’s where it’s supposed to be, and it still doesn’t land right.”
“Maybe that’s the problem,” Onyx said.
Three heads turned towards him.
“What?” Kairo said.
“I said maybe that’s the problem,” Onyx repeated.
“No, I heard you. I just wasn’t expecting you to have an opinion.”
“You’ve played the same eight seconds seventeen times.”
“Eighteen,” Rayne said.
Kairo pointed at him. “Not helping.”
Soahn put down his soldering iron and nudged the spare headset across the floor with the toe of his boot. It stopped beside Onyx’s knee. “Why don’t you try?”
Onyx considered the headset. “Why?”
“Because you fix things,” Soahn said.
“Yes. Tech.”
“So?”
“I don’t fix music.”
“Technically not true.” Soahn’s expression suggested he considered this distinction less important than Onyx did. “You fixed Kairo’s timing.”
From across the room came an immediate: “Hey.”
“It was wrong,” Soahn said.
“I know it was wrong.” Kairo rolled his eyes. “I left it that way on purpose, obviously. Wanted to see if the big guy would get curious and come tell me to turn it off.”
Onyx gaped at him. “Are you joking?”
Flashing him a grin, Kairo said, “Nope. And it worked.”
Soahn laughed before Onyx could say anything about that. Surely there were easier ways to introduce yourself. Onyx frowned at Kairo.
“Anyway,” Kairo added, nodding towards the headset at Onyx’s knee, “this one isn’t supposed to be wrong. And apparently you’re good at fixing problems without even meaning to.”
Still frowning, Onyx picked up the headset.
“Go on,” Kairo said. “I’m sick of this one anyway. If you don’t fix it, I’m deleting the whole thing.”
“He will,” Rayne said. “He’s done it before.”
“That other track was unsalvageable.”
“You cried.”
“I did not cry.”
“You called it your beautiful dead son,” Rayne said.
Soahn lowered his head, his shoulders shaking.
Kairo looked betrayed. “You were there, So. Back me up.”
“I remember the funeral,” Soahn said.
Ignoring them, Onyx rose, put the headset on, and went over to the console. Nearby, Kairo made a small, triumphant noise and leaned in to watch.
“You’re crowding me,” Onyx told him.
“Sorry,” Kairo said, and didn’t make any attempt to move back.
Sighing, Onyx started to analyse the track. He recognised pieces of it: Rayne’s voice sat at the centre, clear in places and distorted in others, while bare chords moved under it and percussion tried to hold everything together. None of the individual parts was bad. Together, though, they were fighting for the same space.
Onyx replayed the section.
Kairo’s equipment made more sense to him now than it had when he first found the relay room. The wiring still looked like an argument, but he’d learned that most of the mess was deliberate. Kairo built quickly, following ideas as they occurred to him and correcting course whenever another one popped into his head. And apparently, his music did the same thing.
Onyx moved one layer, shortened another, listened, then found the stutter Kairo kept trying to remove. But he didn’t remove it. Instead, he changed what happened around it.
The track came through, caught on the stutter and used it, the percussion dropping half a beat before Rayne’s voice returned into the space it left behind.
Kairo’s head snapped up. “Wait.”
Onyx replayed it.
“Again,” Kairo said, shuffling even closer.
Onyx played it, and the transition landed.
“Ha!” Kairo grinned at the display. “That’s it. I knew it.”
“I knew it before you,” Soahn said.
Rayne came over and crouched beside the rig, listening as Onyx played the section once more. His attention stayed on the waveform for a moment before moving to Onyx.
“The layers were competing,” Onyx said with a shrug.
Rayne nodded. “You made room for it.”
Kairo was already reaching across Onyx for one of the controls. “Okay, do that again, but from here. Because if we move this—”
“Move your arm,” Onyx said.
“Right. Sorry.” This time, Kairo moved approximately five centimetres.
“More.”
With a sigh of enormous personal sacrifice, Kairo shifted his chair back.
Soahn picked up his soldering iron. Rayne remained beside the rig, listening, while Kairo restarted the track from the beginning and immediately began talking over it.
Onyx rested his fingers on the synthpad.
For most of his life, an empty display meant waiting. Instructions would arrive eventually: coordinates, targets, routes, objectives. Someone else always knew what came next.
Nothing appeared now.
Kairo changed a layer and looked at him. “What do you think?”
Onyx listened.
Then he reached for the controls.