The Underside doesn’t stay still.

  That's the first thing Kai learns as he follows Aren deeper.

  They've been walking for what feels like hours or maybe minutes. Time down here doesn't track like it does above. No clocks. No synced displays. Just the uneven flicker of old lights and the distant drip of water against concrete.

  Aren walks ahead, never looking back. Silent.

  Kai's legs burn. His ribs ache with every breath. Lix limps beside him, tail flickering unevenly like a dying light.

  "Where are we going?" Kai asks.

  Aren doesn't answer.

  They turn down a narrow corridor. Then another. The walls press closer. The air grows colder.

  Kai tries again. "You said you'd help me find—"

  "I said," Aren cuts in without stopping, "that I'd keep you alive. For now. That's not the same thing."

  Kai's stomach tightens.

  They reach a small room. Empty except for a metal chair bolted to the floor and a single overhead light that hums like an angry insect.

  Aren gestures.

  "Sit."

  Kai doesn't move. "Why?"

  "Because," Aren says, turning to face him fully, "you're either stupid, desperate, or working for someone. And I need to know which."

  "I told you," Kai says. "I'm looking for my brother."

  "Everyone's looking for someone," Aren replies. "Doesn't mean they're clean."

  He crosses his arms, eyes flat and measuring.

  "You walked into VY-4 asking questions about a Zero. Got jumped. Survived. Then I pulled you out. Now you're here." A pause. "That's a lot of coincidences for one night."

  "It's not.."

  "Sit," Aren repeats. Quieter. Colder.

  This time, Kai sits.

  The chair is cold through his clothes. His bracelet sits dark on his wrist. No glow. No feed. Just dead weight.

  Aren stays standing, eyes never leaving Kai's face.

  "Who sent you?"

  "No one."

  "Who knows you're here?"

  "No one," Kai says again. "I left school. Found a note. Started searching. That's it."

  "A note," Aren repeats slowly. "From your brother."

  "Yes."

  "What did it say?"

  Kai hesitates.

  Aren notices.

  "If you lie to me," Aren says quietly, "I'll know. And then this conversation ends very differently."

  Kai swallows.

  "It said he was sorry. That he couldn't explain. That I shouldn't look for him."

  "And you did it anyway."

  "Yes."

  A pause. Longer this time.

  "Why?"

  The question catches Kai off-guard.

  "Because he's my brother," he says. "I'm not letting him disappear."

  Aren studies him. Not with sympathy. With calculation.

  "Family loyalty," he says eventually. "That's either your best trait or your worst one. Haven't decided yet."

  He walks a slow circle around Kai, boots echoing on concrete.

  "Your bracelet. It's blind right now. But when it wakes up, the GPU will ask where you've been. What will you tell them?"

  "I don't know."

  "Wrong answer," Aren says. "Try again."

  Kai thinks fast.

  "I'll say I lost signal. Underground transit malfunction. That it happens in VY-4."

  Aren's expression doesn't change.

  "Not terrible," he admits. "But not enough either."

  He stops directly in front of Kai.

  "Here's the problem, kid. You're mid-tier. Clean record. No priors. The system likes you. If you suddenly go dark for hours, then show up with bruises and a damaged companion, they'll dig. And if they dig"

  "They'll find this place," Kai finishes.

  "Not just this place," Aren says. "They'll find us. The people who live here. Work here. Hide here. And we don't survive that."

  Silence.

  Lix whines softly, pressing against Kai's leg.

  "So why did you save me?" Kai asks.

  Aren doesn't answer immediately.

  He pulls a crate over and sits, elbows on knees, studying Kai like a puzzle that might not be worth solving.

  "Because," he says finally, "you mentioned Paul Virek. And that name… interests me."

  Kai's pulse spikes.

  "You know him?"

  "I know he passed through here," Aren says. "Recently. And people who know Zeros—or are connected to them sometimes carry information worth keeping."

  The tale has been stolen; if detected on Amazon, report the violation.

  "I'm not information," Kai says.

  "Not yet," Aren agrees. "But you might be. If you survive long enough."

  He leans back.

  "Here's the deal. You want to find your brother? Fine. I'll help. But not because I like you. Because Paul's trail leads somewhere I need to see anyway."

  "What do you mean?"

  "I mean," Aren says, "your brother didn't run. He was recruited. By someone. For something. And figuring out who and what means following him back up."

  Kai's breath catches.

  "Back up?"

  "To the surface," Aren confirms. "But first, I need to know you won't break the second the GPU looks at you funny."

  He stands, pulling something small from his pocket.

  "So here's the test."

  Aren holds out a small device. Older tech. No GPU branding. Matte black casing, edges worn smooth from use.

  "This," he says, "will temporarily scramble your bracelet's memory buffer. The last six hours will corrupt. When the system checks, it'll look like a hardware glitch. Common enough in VY-4 that they won't flag it immediately."

  He doesn't hand it over yet.

  "But," he adds, voice dropping, "if you use this and then crack under questioning if you give them anything that leads back here the corruption will look like sabotage. And they'll trace the device signature."

  His eyes lock onto Kai's.

  "Which means they'll find me. And everyone I work with."

  Kai stares at the device.

  "So you're trusting me," he says slowly, "by giving me something that could destroy you."

  "No," Aren corrects. "I'm testing you. If you take this and use it, you're in. Completely. No backing out. No second thoughts. You'll be as guilty as the rest of us."

  He steps closer.

  "But if you refuse if you'd rather take your chances with the GPU and leave here clean, I'll walk you to a surface exit right now. You'll forget the last hour. Go home. Move on."

  The device sits in Aren's palm. Small. Innocuous. Lethal.

  Kai looks at it.

  Then at Lix, curled at his feet, tail still glitching with broken light.

  Then back at Aren.

  "If I take this," Kai says carefully, "and they catch me"

  "They'll classify you as Zero-adjacent," Aren finishes. "Possibly hostile. You'll lose your score. Your home. Your future. Everything."

  A beat.

  "But you'll still have a chance to find Paul."

  Kai's hand trembles.

  He thinks of his mother. The apartment. School. Nolan. Everything safe and measured and normal.

  Then he thinks of Paul's face. The note. The empty room.

  I'm sorry. Don't look for me.

  Kai reaches out.

  Takes the device.

  "Show me how it works," he says.

  For the first time, something almost like approval flickers in Aren's eyes.

  "Good," he says. "Now you're starting to understand how this place works."

  He takes the device back, crouches beside Kai, and attaches it to the bracelet's underside. A faint click. Then a soft hum.

  The interface flickers.

  Lines of corrupted data scroll past—timestamps fragmenting, locations scrambling, biometric reads turning into noise.

  Then it goes dark.

  When it lights up again, the timeline is clean. No gaps. No alerts.

  Just a smooth buffer error covering the last six hours.

  "It'll hold for a while," Aren says, detaching the device and pocketing it. "Long enough for you to get home. Act normal. Let the system assume you were unlucky."

  He stands.

  "Welcome to the Underside," he says. "Now let's see if you survive it."

  Kai exhales. Didn't realize he'd been holding his breath.

  "Does this mean you trust me now?"

  Aren's mouth twitches. Not quite a smile.

  "No," he says. "It means you're useful. And guilty. That's better than trust."

  "Now that you're in," Aren says, leading Kai down another corridor, "there are people you need to meet. But remember they didn't choose you. I did. If you screw up, it's on me. And trust me, they won't let me forget it."

  Voices echo ahead. Low. Cautious.

  They emerge into a wider junction.

  Three figures look up as Kai enters.

  The first is a woman carving symbols into the concrete with a heated blade. Lean. Scarred. Her hair hacked short with no concern for symmetry. A burned band circles her wrist what's left of a bracelet, melted and dead.

  She looks at Kai.

  Then at Aren.

  "You brought someone?" she asks flatly.

  "Mara," Aren says. "He's clean. For now."

  "For now," she repeats, eyes sharp. "That's comforting."

  She stands slowly, blade still warm in her hand.

  "Live bracelet," she says, nodding at Kai's wrist.

  "Blind," Aren replies. "Corrupted buffer. He's off-grid."

  Mara studies Kai like a problem that might solve itself if she waits long enough.

  "Off-grid doesn't mean safe," she says. "Blind things wake up. Especially when they panic."

  Kai swallows. "I'm not panicking."

  Mara smiles. Thin. Sharp.

  "That's worse."

  Lix bares his teeth, a weak crackle snapping along his tail.

  "Touch him," Kai says, voice tight, "and I swear—"

  "And you'll what?" Mara asks. "Report me?"

  Aren moves.

  Fast.

  He plants himself between them, palm raised not threatening, just final.

  "Rule one," he says. "No sudden violence unless you're ready for everyone to join in."

  Mara holds his gaze for a long second.

  Then steps back.

  "Your risk," she mutters. "Don't bleed it on us."

  She turns and goes back to carving.

  Kai exhales, realizing only now that he'd been holding his breath.

  "That was the hostile one," he says quietly.

  Aren snorts. "No. That was the polite warning."

  The second Silencieux doesn't look dangerous at all.

  He's older late forties, maybe more. He sits on a crate beside a jury-rigged heater, sipping something that smells faintly like burned coffee.

  "New face," he says as they pass. "Still got fear in his shoulders."

  Kai stiffens.

  "Relax," the man says. "I'm neutral. Name's Ivo. I fix things that don't want to stay fixed."

  Aren nods once. Respect.

  Ivo's gaze drifts to Lix.

  "Fox core's fried," he says. "But not dead. Interesting."

  "Can you help him?" Kai blurts.

  Ivo considers, tilting his head.

  "Eventually. But not before you make it through the night."

  "The night?" Kai repeats.

  Ivo smiles, thin and tired.

  "Rule two," he says. "If you're still here when the lights cycle low, you belong. If you're not… you didn't."

  "That's not a rule," Kai mutters. "That's a threat."

  "No," Ivo says gently. "That's math."

  They move deeper.

  Aren checks something on a cracked wrist device not a bracelet. Something older, independent.

  "We've been down here almost two hours," he says. "You're holding up better than most."

  Kai almost laughs. "This is me holding up?"

  "Yes," Aren says flatly. "I've seen people break in twenty minutes."

  They reach a wider junction. Three tunnels split off. One hums with power. One smells like water and rust. The third is almost completely dark.

  Aren stops.

  "Rule three," he says. "When you're given a choice—"

  A shape drops from the ceiling.

  Hard.

  Kai barely registers the movement before something slams into him. He hits the ground, breath knocked clean out of his lungs. Lix yelps, skidding away.

  A blade flashes.

  Not metal ceramic. Matte black.

  The attacker straddles Kai, knee pinning his chest.

  "No real bracelet," the man snarls. "No valid ID. That means you're either valuable or disposable."

  Kai's vision blurs. Pain spikes through his ribs.

  Aren doesn't move.

  "Get off him," Aren says calmly.

  "Test?" the attacker asks without looking away from Kai.

  "Yes."

  The blade presses closer to Kai's throat. Cold. Precise.

  "Say it," the man whispers. "Say you're done. Say you want to go back up."

  Kai's heart hammers.

  The surface flashes in his mind his mother's face, the door with the relocation notice, the city pretending nothing was wrong.

  Then Paul's name. The way it still feels unfinished.

  "I'm not going back," Kai says hoarsely.

  The blade doesn't move.

  "Say it again."

  "I'm not going back," Kai repeats. Louder. Angrier. "Not without him."

  A beat.

  Then the weight lifts.

  The attacker stands, sheathing the blade with practiced ease.

  "Loyal enough," he says. "Still stupid."

  He offers Kai a hand.

  Kai hesitates, then takes it.

  The man grins. Sharp. Predatory.

  "Name's Jax. That was the test."

  Kai's hands shake. He presses them flat against the ground to hide it.

  "What if I'd said yes?" he asks, voice rougher than he wants.

  Jax shrugs.

  "Then we'd have walked you to a surface exit and wiped your last hour of memory. Or killed you. Depends on the day."

  Kai tries to stand. His legs don't cooperate immediately. Lix limps over, pressing hard against his side.

  "Fear's honest," Jax adds, quieter. "Panic gets you killed. Remember the difference."

  Kai nods. Doesn't trust his voice yet.

  He looks at Aren.

  "You were just going to let that happen?"

  Aren meets his gaze.

  "Yes."

  Something cold settles in Kai's chest.

  "Rule four," Aren says. "No one down here saves you for free."

  They move again.

  Time still doesn't behave. Minutes stretch. Hours compress.

  They stop near a terminal half-buried in concrete. Screens cracked. Wiring exposed. But alive.

  A figure crouches there, fingers dancing across fractured glass. Their knees press into the bare concrete, fabric already worn thin. A loose strand of hair has slipped out from under their hood, catching the blue from the screens.

  “Zera,” Aren says.

  The figure doesn’t look up. Up close, Kai can see ink smudged along their thumb and the faint tremor in very human tendons.

  “I pulled what I could,” they say. Voice androgynous. Efficient. “Noise storms ate most of it.”

  Kai steps closer.

  A familiar name flickers on-screen.

  PAUL VIREK

  Last unregistered presence: Underside corridor — VY-4 depth

  Timestamp: Friday 18:42

  Kai's breath catches.

  Friday. Less than six hours ago.

  Before Kai even found the note. Before he started searching.

  Paul had already moved.

  Kai's hand hovers over the screen, as if touching it will rewind time.

  "He was here," he says. Voice barely holding. "Six hours ago. He was right here."