The maintenance bay had the tired look of a room that only ever saw people at their worst.
Concrete sweated condensation. The ceiling hummed with idle chargers. Along one wall, a line of half-gutted drones hung from hooks like skinned metal animals, their wiring innards tagged and numbered. Someone had painted a smiley face on one of the tool lockers and then shot it through the eye.
Bay Nineteen, the sign over the door said, as if that explained anything.
Arden lingered just outside the threshold.
He wasn't supposed to. Orders had been clear enough: "Recalibration session. Kell and Drayven only." Silex hadn't said it to his face, but the implication had hung in the air like ozone.
Still. The collar hadn't buzzed when he stopped here on the way back from Echo Court. That counted as permission in his book.
Inside, Darius sat on the edge of a maintenance bench, armor peeled down to his waist, undersuit damp and dark with old sweat. His back was a map of scars and fresh bruises. The Shadow Host had left its fingerprints there in livid purple and yellow, a story written in blunt force.
Kai crouched on a rolling stool in front of him, half-immersed in a diagnostic rig.
Fiber cables spidered from Kai's fingers into an open port on Darius's collar base, lights chasing themselves along the lines in little stuttering pulses. A holo-slab hovered to Kai's left, displaying Darius's vitals and leash telemetry in spiky graphs.
Neither of them had noticed Arden yet.
Good, Arden thought. Let them have this. He stayed where he was, in the shadow of the doorway, just close enough to hear.
"You know," Kai said, "most people who almost murder their own unit get at least a week off before maintenance."
His tone was conversational, not accusing. That somehow made it worse.
Darius didn't look at him. His gaze stayed fixed on the far wall, where a rack of replacement armor plates gleamed dully.
"Most people haven't had their ghosts weaponized," Darius said. "I don't rate time off."
"Ghosts," Kai repeated. "You make it sound romantic."
"Nothing romantic about it," Darius said. "Just old orders that never got told they were done."
Kai's hands moved with precise economy, adjusting a dial, tightening a clamp. The cables shifted; Darius's collar flickered, a brief pulse of cold blue.
"Shadow Host imprint," Kai murmured, reading the slab. "Architect-era soldierware, stapled into your nervous system in a war no one wants on the record. You were a contractor, not a priest. They bought your rage and forgot the receipts."
Darius snorted once, humorless. "You read a lot out of squiggles."
"That's my job," Kai said. "Translate squiggles into excuses or execution orders, depending on who's paying."
He glanced up then, eyes catching Darius's for a moment.
"Do you remember it?" Kai asked. "The Host. When it takes you."
Darius's jaw worked. For a second Arden thought he wouldn't answer.
Then: "Yes. And no."
"Helpful."
"I remember everything after," Darius said. "My body knows it all during. Every angle, every shot. The math of it. But there's a layer over the top. Like watching someone else's helmet cam. You know it's you, but the part that says I didn't sign this stays somewhere behind the glass."
"Neural partition," Kai said. "Architects loved those. Gave them plausible deniability. 'See, Your Honor, technically the subject wasn't conscious when he burned the village.'"
"Does that help?" Darius asked.
"Legally?" Kai said. "Sometimes. Morally? Not a damn bit."
Silence settled between them, thick as oil.
Arden felt it too, crouched just outside, hand on the cold frame of the doorway. The taste of rust chapel air hadn't left his throat yet. The look in Darius's eyes when the cascade hit—white and not quite human—kept replaying whenever he blinked.
"You think I'm broken," Darius said. The way he said it, it wasn't a question.
Kai hesitated. The holo-slab painted his face in pale vectors.
"I think," Kai said slowly, "that you're running two operating systems on hardware built for one. One of them is forty years out of date and was written by people who thought empathy was a bug. So, yes. From a technical standpoint? You're fucked."
Darius's mouth twitched. "Technical standpoint," he echoed.
"But," Kai went on, fingers dancing across the interface, "you also threw yourself in front of us when the Rust Saints' transmitter went up, let a god you didn't believe in pull your strings, and somehow clawed your way back in time not to gut Arden."
"That last part was him," Darius said quietly. "Not me."
"Point," Kai said. "Still. Shadow Host was designed to run until everything in its path was red and quiet. You stopped. That matters."
Darius's throat worked. "Does it."
"Depends," Kai said. "What are you asking? Whether you're a monster? The answer is yes. So am I. So is Arden. So is this whole tower. But monsters come in versions. There's the kind that enjoys it, the kind that pretends it's righteous, and the kind that hates every second and does it anyway to keep worse things from getting through the door."
He shrugged. "Guess which one you're trending toward."
Darius didn't reply.
Kai flicked another setting. Darius's collar pinged, a faint ripple under his skin. The big man flinched, almost imperceptibly.
"There," Kai said. "I've throttled the Host cascade thresholds. You'll still trigger, but not on the first hymn someone whispers in a sewer. Needs a stronger signal, triple convergence—Architect code, leash feedback, trauma recall. Gives us more room between you and total apocalypse."
"And when it hits?" Darius asked.
Kai tapped the slab. An image popped up—Darius's skeletal overlay, nodes lit up along his spine and skull.
"I can't uninstall the soldierware without taking you with it," he said. "Architect code's woven too deep. But I can build a firewall of sorts."
He looked up again, eyes sharp now.
"You trust me?"
That earned him a real look. Darius turned his head, studying Kai like he was assessing a new weapon system.
"You're asking that now," Darius said.
"Seems relevant," Kai said. "Given that what I'm about to suggest could either save your life or erase you in a very creative way."
"Out with it," Darius said.
Kai took a breath.
"I want to build a kill-switch," he said. "For the Host. Hard-coded, wired into your implant lattice. You start to cascade, Arden or Lyra or I can hit it. It slams a shutdown sequence through the imprint before it fully boots."
Darius's shoulders rolled back, instinctive tension. The sound of it echoed off the concrete.
"You want to put a leash on my leash," he said.
"Yes," Kai said. "Because right now, the only person with a real off switch for you is Silex, and his version kills all of us. I like living. I also like not being turned into paste by your other personality. So. Parallel solution."
"You're talking about execution code," Darius said. "Don't dress it up in nice words."
Kai grimaced. "Fine. A partial execution. Targeted neural collapse if you go full Host. Maybe it locks you into your body instead of ejecting you. Maybe it fries the imprint node so hard that soldierware can't boot again. Maybe it just stops your heart. Lots of maybes."
"Lots of graves in those maybes," Darius said.
"Tell me something," Kai said. "You'd rather risk tearing us apart again?"
The question sat between them, humming.
Arden's collar warmed against his throat. He shifted, weight on his heels, resisting the urge to step in and cut the whole conversation off.
He didn't. This was theirs. Ash and wire, working out whether to light a fuse.
"What about consent?" Darius asked. "You don't get to write death code into a man without asking who owns the body."
"I just did," Kai said. "I asked if you trust me."
"That's not the same."
Kai's jaw tightened.
"Darius," he said. "The system already owns you. They own me. They own Arden, Lyra, Seraphine. Your collar can kill you on a whim. Mine can lock my brain in a loop anytime it wants. We're already on a kill-switch."
"So you're saying adding another one doesn't matter," Darius said.
"I'm saying at least this one would be in our hands," Kai replied. "Your unit. Not theirs."
He paused, letting that sink in.
"You always talk about holding the line," Kai added, quieter. "About being the wall between the city and the people who'd burn it. Let us hold the line on you when you can't."
Darius looked down at his own hands.
They were big hands. Scarred knuckles, callused palms, veins like cables. Arden had seen them cradle a wounded civilian's head like something breakable. He'd also seen them snap a man's neck so cleanly the body hadn't realized it was dead for a full second.
"They told us," Darius said slowly, "back in the contracts. Shadow Host is a blessing. Speed, precision, no hesitation. God in the reflex arcs. We signed because we thought never hesitating meant never failing. We didn't understand it also meant never forgiving."
"You were young," Kai said.
"I was old enough to read the fine print," Darius replied. "I read it anyway. I signed anyway. That's on me."
The words landed heavy. Arden felt them in his own chest.
He thought of his own deal—the rope or the collar. He'd signed, too. Different contract, same ghost clause.
"You think guilt is ownership," Kai said. "Because you signed, it's yours forever. That's not how code works. Whoever wrote it bears the real sin. You just executed."
"That's convenient," Darius said.
"For you?" Kai shrugged. "Not really. I carry my own ledger. Every hack, every file I altered, every debt chain I erased. People starved because I severed the wrong account once. Kids lost housing in a dome because I thought I was punching up and didn't see the trickle-down. I'm not saying guilt isn't real. I'm saying it's bad at target acquisition."
He sat back slightly, unplugging one cable, reseating it.
"From a logic standpoint," Kai went on, "the question isn't 'am I a monster.' It's 'given that I'm a monster, what do I choose to do next.'"
"Logic standpoint," Darius repeated again, but this time there was something almost amused under it. "You really can't help yourself."
"No," Kai said. "Code is the only religion I have left."
The bay lights flickered as some distant system cycled. For a moment, the two of them were silhouettes—one broad and solid, one thin and wired, both collared, both tethered to machines.
"Build it," Darius said at last.
Kai blinked. "That's a hell of a 'go on.'"
"The switch," Darius said. "Build it. Code it. Whatever you call it. But under three conditions."
Kai's fingers hovered over the slab. "I'm listening."
"First," Darius said. "Only Ø7 gets the trigger. You, Lyra, Seraphine, Arden. No one else. Not Silex, not the priest from Echo Court, not some Crown statistician who thinks I look bad on a graph. You sandbox it away from their toys."
"That's… difficult," Kai said. "But not impossible."
"Second," Darius said. "No auto-trigger. No algorithm choosing when I die. A human makes the call. Always."
Kai nodded once. "Can do."
"Third," Darius said. His voice dropped. "If it comes to it—if I go Host and you have to hit it—I want it to be Arden."
Kai stared at him. "You serious."
"Lyra would hesitate," Darius said. "Seraphine would take too much of it into herself. You…" He shook his head. "You live too much in your own skull. You'd spend the rest of your life re-running the code. Arden—"
He stopped. Took a breath.
"Arden understands killing family," Darius said, finally. "He's done it before. He knows the shape of that wound. He'll carry it and keep walking."
The words hit Arden like someone had opened a hatch under his feet.
He hadn't told Darius the Vultures story. Not the whole of it. Some parts you didn't say out loud.
But Darius had read his file. Of course he had. Command anchors did their homework.
Kai sat back, eyes flicking toward the doorway for the first time, like he'd just remembered there might be ears.
Arden met his gaze.
"You know he's there," Kai said dryly.
"I knew five minutes ago," Darius said, without turning. "He walks heavy when he thinks he's being quiet."
"Good to know my stealth game is shot," Arden said, stepping into the bay.
His collar didn't sting him for entering. Small mercies.
Kai rolled his eyes. "You ever heard of boundaries?"
"Once," Arden said. "Didn't like them."
He came closer, boots echoing lightly on the concrete. Up close, he could see the fatigue carved into both their faces. Kai's pupils were still a little blown from interface time, faint blue circuit-lines pulsing at his temples. Darius looked like someone had scraped the inside of his skull with a wire brush.
"What did I miss?" Arden asked, keeping his tone easy.
"We're drafting my will," Darius said.
Kai snorted. "We're building a safety net. He's just chronic about dramatics."
Arden leaned against a tool locker, arms loosely folded.
"Kill-switch?" he guessed.
Kai blinked. "You always this quick?"
"I know Silex," Arden said. "If he says 'enhanced oversight,' it means he's already got a way to kill you that hurts everyone else. Kai doesn't like binaries, so he's making a third option. How'd I do?"
"Disturbingly accurate," Kai said.
Darius watched him, quiet.
"They want you to hold the leash," Darius said.
"Do they," Arden said.
"I do," Darius corrected.
Arden blew out a slow breath. "That's fucked up, Kell."
"Yes," Darius said. "So is what lives in my spine. I'd rather the man who dragged me out of the chapel be the one to end it if he has to."
Arden looked away for a second, up at the hanging drones.
"You sure about that?" he asked. "I'm not exactly known for restraint."
"You are," Darius said. "You just use it in the wrong places."
Kai shifted on his stool. "Look, I'm not asking you to sign in blood," he said. "Not yet. I haven't even written the thing. But if we build this, it only works if you're willing to press the button when the time comes."
"What about you?" Arden asked. "You wrote it. You could press it."
Kai's mouth flattened.
"I've spent the last few years being the system's hand on a lot of invisible kill-switches," he said. "Debt chains, criminal records, health access. Flip a bit, someone lives. Flip another, someone dies. I did it from a distance. Mouse click, neural pulse. Addictive power. You don't walk away from that clean."
He met Arden's eyes.
"I'm trying to get out of the business of deciding who deserves to die," Kai said. "I'll build the device. I don't want to be the one who uses it."
"And Lyra?" Arden asked.
"Lyra would see too much," Darius said. "She'd feel my fear, the Host's hunger, your guilt, Silex's satisfaction, the Architect's laughter. She'd drown in it."
Seraphine's name went unspoken, but Arden could feel her ghost in the room anyway—half a smirk, half a knife.
"She'd do it if no one else could," Darius said. "But she'd never forgive herself. I don't want that on her."
"So that leaves me," Arden said.
"Yes," Darius said simply.
Arden laughed once, sharp and short.
"This family really knows how to hand out gifts," he said.
"No one else I'd rather burden," Kai said, deadpan.
The joke shouldn't have helped. It did, a little.
Arden rubbed his thumb along the underside of his collar.
He remembered the rope, the drop, the system glitch that had turned his execution into a viral miracle. Variable Zero. Saints whispering his name now in rust-lit tunnels.
He remembered Forty-One, burned to ash in the Purge Sweep. The way her eyes had looked when she'd shoved him under the collapsed scaffold. Do what you have to, boy.
"Okay," he said.
Both of them looked at him.
"I'm not promising to hit your off switch," Arden said. "I'm promising to be there if it comes to that. And if I do it, I won't do it because the system tells me to. I'll do it because you ask me, now, while you're you."
Darius's shoulders eased a fraction. Not much. Enough.
"That's all I'm asking," he said.
Kai exhaled like he'd been holding his breath for twenty lines.
"Great," Kai said. "Now that we've firmly established that we're all comfortable with premeditated murder of our friends, can we go back to the technical side?"
Arden snorted. "You're the one who pulled us into morality class."
"Hey, you're the conscience glitch," Kai said. "I'm just the guy writing malware for God."
The line hung there. Poetic, almost. Arden felt the edges of it catch on something in his chest.
"Conscience as malware," he said. "That what you think?"
Kai rolled his neck, listening to the faint crackle of joint augments.
"The system does," he said. "Look at us. Every time you hesitate, the collar screams. Every time Lyra flinches at a bad order, her fragment hums. Seraphine has to twist her empathy into performance just to make it usable. Darius's guilt is treated like a malfunction to calibrate away. If morality aligned perfectly with Obedience, they wouldn't have needed the leashes."
Darius's gaze drifted to the diagnostic slab, where his own stats still crawled.
"You think they're going to try to patch it out of us," he said.
"They already are," Kai said. "That's what Echo Court was. A code review. They watched the sewer footage and marked every instance of 'excessive compassion' as a bug. We survived today because Seraphine turned our flaws into a marketable narrative. Tomorrow, they'll be back in the lab, asking how to design Dogs that don't try to save cult kids."
Arden thought of Quinn's polite smile, the way she'd said restraint like it was a brand name.
"What's the alternative?" Arden asked. "Turn it off. Become what they want. No hesitation, no guilt. Shadow Host in all of us."
"Alternative is we keep the malware," Kai said. "We hide it when we have to. We weaponize it when we can."
"Mercy as a weapon," Darius said.
"Why not?" Kai said. "We live in a city where every kindness is a security risk. Start treating compassion like contraband. Smuggle it where the cameras can't see. Corrupt their clean narratives with messy humanity."
The words hit Arden harder than he expected.
"Conscience as a virus," he said, almost to himself.
Kai shrugged. "Every system fears what it can't sanitize."
From the corridor, footsteps echoed—light, quick. A moment later, Lyra appeared in the doorway, eyes unfocused, collar-glow low.
"There you are," she said softly.
She took in the scene at a glance: cables, holo-slab, the tension still crackling in the air.
"Am I interrupting an execution pact?" she asked.
"Yes," Kai said.
"No," Darius said.
"Maybe," Arden said.
Lyra's mouth curled, the smallest ghost of a smile.
"Good," she said. "You're learning to answer like a committee."
She stepped into the bay, fingers brushing the doorframe as she passed Arden. He felt the faint tingling buzz of her skin augments.
"The tower's quiet," she said. "Quieter than it should be after Echo Court. That means people are writing stories about us upstairs and don't want the ghosts to overhear."
"We were just talking about that," Kai said. "Conscience as malware."
Lyra tilted her head.
"Malware gives the system headaches," she said. "We're more like undocumented features."
Arden snorted. "You would call us that."
"Besides," Lyra went on, drifting closer to Darius. "Without bugs, code never evolves. Corruption is how new patterns emerge."
She laid two fingers lightly on Darius's collar, near the port where Kai's cables fed in. The slab's graphs flickered, subtle shifts in waveforms.
"Your Host imprint is… restless," she murmured. "Kai?"
"I've damped the thresholds," Kai said. "I'm going to build a manual override for the worst-case scenario. He consented."
Lyra's eyes met Darius's. There was no judgment there. Just a quiet, aching understanding.
"Then we'll make sure the worst-case scenario stays hypothetical," she said.
"That's not how statistics work," Kai muttered.
"Statistics can be lied to," Lyra said. "We watched Seraphine do it in Echo Court."
A shadow passed over her face at the name, something like fatigue, something like fondness.
"She says hi, by the way," Lyra added. "From the showers. She's making friends with the bruises the tribunal didn't see."
"Of course she is," Arden said.
The bay felt smaller suddenly, stuffed with too much vulnerability for a room built for tools.
"We done?" Arden asked Kai.
Kai checked the slab one last time, flicking through readouts.
"Collar's stable," he said. "Host imprint at low simmer. If he goes near any more Architect residue in the next forty-eight hours, I want him on a short leash and a long prayer."
"Noted," Darius said dryly.
Kai unplugged the last cable. The lights dimmed. Silence rushed in where hum had been.
Darius rolled his shoulders, testing the fit of his own skin.
"Feels… heavier," he said.
"That's the point," Kai said. "Weight slows acceleration. Gives us time to grab you before you break the sound barrier."
"You're terrible at metaphors," Arden said.
"I'm excellent at them," Kai replied. "The problem is your taste."
Lyra glanced between them, then at Darius.
"Walk with me," she said to him. "Silex will want a formal check-in. Better to arrive looking like you chose it."
"I did choose it," Darius said.
"Then let's make sure he never doubts that," she said.
They left together, Lyra's hand resting lightly on Darius's arm. Two ghosts, one made of ash, one of static.
Arden watched them go.
"You know this is a terrible idea," he said quietly to Kai, when they were alone.
"Which part?" Kai asked. "Giving the walking weapon a custom kill-switch or trusting you with it?"
"Treating mercy like contraband," Arden said. "Smuggling it around Silex. Playing god with each other's lives."
Kai leaned back against the bench, letting his head thump lightly against the tool rack.
"You want clean lines," he said. "You're in the wrong job."
"I wanted rope," Arden said. "They gave me a collar instead."
Kai's expression shifted, just for a second. Something like sympathy blinked in and out.
"For what it's worth," he said, "if you ever want me to write one of those switches for you, I won't."
"That mean you like me?" Arden asked.
"That means the system already has too many ways to kill you," Kai said. "I'd rather spend my time coding exits instead of extra doors into your neck."
He pushed off the bench.
"Come on," Kai said. "Night-cycle's short and Silex will have us back under lights soon enough. Get what passes for rest. Your conscience malware needs downtime."
Arden fell into step beside him as they left the bay.
In the corridor, the tower's hum wrapped around them—vent fans, distant drone traffic, the faint murmur of Veil feeds behind the walls. Somewhere above, Echo Court's records were being edited, their sins rearranged into palatable shapes.
They walked in silence for a while.
"You really think conscience is malware?" Arden asked finally.
Kai considered.
"I think in this city," he said, "it's the only virus left worth catching."
Arden touched his collar again, feeling the steady, possessive thrum.
"Then let's make it contagious," he said.
Kai huffed a small laugh. "Now who's doing metaphors."
"Don't get used to it," Arden said.
They turned the corner toward the barracks. Ahead, through a narrow viewport, Arden caught a glimpse of the Span's night: domes glowing, rain falling in slow, glittering lines. For once, the drops looked like water, not static.
He thought of Silex's words: The Obedience Machine runs on momentum. Don't let it stall.
Fine, he thought.
Let it run.
We'll just start changing the code under its feet.
The ash walked beside the wire, and somewhere between them, something like a heart kept time with the machine.
For now, that was enough.