It would have been a dignified retreat if the corridor hadn’t decided to offer us one more riddle on the way out.

  The choke point appeared a few terraces later: a narrow pass where two buildings leaned toward each other, the walkway between them pinched to barely a couple of meters. The rail on the outer edge had grown extra ribs, like someone had grafted vertebrae onto it; the inner wall bore a set of deep, repeated gouges clustered low.

  “Hard no,” Trevor said immediately. “We are not taking the whole team through that.”

  “I can scout it,” Frankie said. “Ghost-only. Zero mass, zero contact, zero snacks.”

  He waggled his fingers.

  “Worst case, the big whatever ignores me because I don’t have a nutritional density rating.”

  Mercy hesitated.

  “I will also send a drone,” she said. “I do not trust the city’s field behavior where we observed those impact scars.”

  “Wait,” Frankie said. “You don’t trust the alien city. You trust me?”

  “I trust that you will complain loudly if anything goes wrong,” she said.

  “I accept this,” he said.

  We tucked ourselves into a slightly wider alcove just shy of the pinch point. Trevor anchored the sled again, eyes flicking between physical railings and Mercy’s hazard overlay like he expected either to bite.

  The scout drone flickered to life and zipped ahead, hugging the ceiling. Frankie took a breath he didn’t need and stepped off the terrace.

  His avatar slipped into Ghost mode almost lazily this time, edges losing solidity, color desaturating. He flowed around the others and down the corridor behind the drone, feet a suggestion rather than a force.

  “Feed steady,” Mercy said. “Field gradient ahead… anomalous, but not actively hostile.”

  I watched the drone’s forward camera on my HUD: stone, stone, more stone, then a wider opening, a glimpse of a plaza beyond.

  The air ahead seemed… thicker. Not visually; the image didn’t blur. But the sound dropped a notch—ambient hum vanishing, distant trickles cutting off—as if we’d stepped into a padded room. The hair along my arms prickled under the suit, like static looking for somewhere new to live.

  “Losing acoustic detail,” Mercy muttered. “Adjusting filters.”

  The drone rose, giving us a higher angle over the lip of the plaza.

  For a heartbeat, the scene was perfectly mundane: another wide terrace, a cluster of structures, light-rivers looping through. Then something huge moved between two buildings and every sensor we had coughed at once.

  There wasn’t even a proper silhouette to look at.

  Light bent wrong along a curve that didn’t belong to any architecture I could see. Edges that should have thrown shadows didn’t. A whole chunk of the feed glitched to gray static for half a second exactly where my brain insisted a shape ought to be.

  Pressure skated across my sinuses, a faint, phantom squeeze, and there was a ghost of hot-metal ozone in the back of my throat—like breathing the edge of a thunderstorm that only existed in Mercy’s diagnostics.

  “It swept like the trace of a field,” Mercy said sharply, “but through multiple sensor layers at once. Interference. Field occlusion.”

  On my HUD, Frankie’s avatar—composited over the drone’s position—flickered as the glitch passed through him. For a single frame, his outline… wasn’t.

  Something taller, with angles my hindbrain immediately vetoed as “not for you,” overlaid his form: longer limbs, a bend in the middle that didn’t map to human joints, hard geometry where his shoulders should have been.

  Then it was gone, replaced by Frankie’s usual messy hair and flailing hands.

  “Okay,” he said, voice a little higher. “Okay. That was a lot of nothing. A very big, very deliberate nothing.”

  “Fall back,” Trevor said. “Now.”

  “Already doing that,” Frankie said.

  The drone pivoted and zipped back toward us; Frankie’s ghost followed, flickering once as if something had tried to catch the hem of his field and missed.

  “Whatever that is,” Mercy said, “it is either masking itself or being masked. That occlusion was not a passive property. It was… curated.”

  There was a faint lag before she said “curated,” like she’d borrowed my word and wasn’t sure she liked it here.

  “What did you see?” Chloe asked when Frankie reappeared, solidity snapping back like a rubber band.

  He stared past us at the pinch point for a moment.

  Unauthorized duplication: this narrative has been taken without consent. Report sightings.

  “I saw a plaza,” he said slowly. “I saw architecture. I saw light. And then I saw where something ought to be and my brain said ‘no thank you, that space is occupied by error messages.’”

  He shuddered theatrically, then more genuinely.

  “Also,” he added, “I nearly fell through the floor when the city flicked the local grav for a second, and I am not getting stuck halfway through a balcony in solid mode while a stealth kaiju strolls past, so can we please go home now?”

  “Yes,” Trevor said, with feeling. “We can go home.”

  We turned back toward the smooth boundary line and the relative comfort of noisy dust.

  ?

  The city didn’t wait for us to decide exactly how done we were.

  As we worked our way back through the terraces, the environment changed. Not in big, dramatic ways—no slamming gates, no flashing hazard glyphs. Just… edits.

  A door we’d used on the way out now sat with its edges faintly glowing but refused to open when we approached; its glyph band pulsed a calm, unwavering “no” that even I could parse. The light-river that had previously traced a neat route along one balcony now kinked away at an earlier intersection, flowing down a different path and leaving our original shortcut dim.

  “Mercy?” Trevor said. “Status on corridor ratings?”

  “Adjusting,” she said. “Several routes near the gouge zone are trending from green toward yellow. One has just flipped to orange.”

  “Orange?” I repeated. “We had an orange?”

  “I do now,” she said. “I added it.”

  Rails we’d walked past earlier now sprouted extra verticals, turning open overlooks into latticed barriers. A viewpoint that had given us a nice line-of-sight down toward the lower terraces now had a new waist-high wall extruded across it, as if the city had decided we did not, in fact, need to see whatever lay beyond.

  On one ramp, a narrow side passage we’d ignored that morning now glowed invitingly; the main route’s floor lights had gone dim, their color shifting toward a muted amber that felt like a polite suggestion to reconsider our life choices.

  “We’re being rerouted,” Chloe said.

  “Gently,” Frankie added. “Like when a nav system says ‘recalculating’ in that very calm voice right before you drive off a cliff.”

  “Please do not drive off any cliffs,” Mercy said.

  “Wasn’t planning on it,” I said.

  We followed the city’s not-quite-suggestions, letting the brighter paths guide us away from the places where gouges and vitrified scars clustered.

  Halfway back, Mercy cut the feed from one of the distant drones mid-sentence.

  “What happened?” I asked.

  “External access denied,” she said. “The city has rescinded my sensor privileges in that sector. It allowed me to look while whatever-that-is passed through. It is now… closing curtains.”

  “On us,” Trevor said.

  “On itself,” Chloe countered. “We’re not its primary audience.”

  A few terraces later, the background noise crept back. Tiny rustles. Flickers of motion at the corners of my eyes. A brief flash of something with too many legs vanishing into a wall crack.

  The dust under our boots got messy again.

  “Back in the soft play area,” Frankie said. “Population: us, the skittering things, and the aggressively nurturing railings.”

  As if on cue, the rail beside him grew another five centimeters when he leaned over it.

  “See?” he said. “Baby gate.”

  “Mercy,” Trevor said quietly, as we rounded the last curve toward the gate terrace. “Do you have enough data to make any kind of statement about… whatever is moving out there?”

  “A statement,” she said slowly, “yes. An explanation, no.”

  “Statement?” I prompted.

  “The city is sweeping something large through its deeper sectors,” she said. “While it does so, all paths available to you trend toward ‘children allowed.’”

  I didn’t like the way she emphasized “you.”

  Neither did my stomach.

  ?

  Back at camp, everything looked disconcertingly normal.

  The printer hummed away in its corner, cycling feedstock. The shelter walls glowed in their usual soft gradient. The terrace outside still opened onto the same layered vistas of greenery and stone, light-rivers flowing like someone had installed tasteful accent strips across an entire civilization.

  If you didn’t know better, you could pretend this was an ordinary field day.

  Mercy threw a simplified map into the air over the fold-out table.

  Our little green bubble around the gate terrace had grown a few tendrils along the routes we’d just taken. Two new regions glowed in a muted blue-green—our brief excursions past the smooth boundary and up to the pinch-point. Past those: zones shaded a dull red, ringed with a faint stippling of hazard markers and tiny, locked symbols.

  Thin lines traced around the red zones in a loose ring.

  ECOLOGICAL QUARANTINE CORRIDOR, said the text when I focused on one. TRANSIT: RESTRICTED.

  “Looks like someone dropped a salad bowl into a bigger salad bowl,” I said. “We’re in the lettuce. The big thing gets the croutons.”

  “That metaphor got away from you,” Chloe said.

  “Most of my metaphors are on the run,” I said.

  Frankie folded his arms and squinted at the density overlay Mercy had layered in behind the hazard ratings.

  Dots pulsed where her microfauna sensors had picked up motion over the last few hours. Out in the green zones, they dithered everywhere: little clouds clustering around terraces, pipes, plant clusters. Closer to the quarantine corridors, those clouds got denser.

  Right up to the lines.

  Then—nothing.

  “Okay,” he said slowly. “See that? That’s wrong.”

  “You’re going to have to be slightly more specific,” I said.

  “In a normal ecosystem,” he said, “if there’s a big predator, prey density tapers off as you get closer to where it hunts. Right? Scared things avoid the teeth. You get gradients.”

  He gestured at the map.

  “This isn’t a gradient,” he said. “This is… fine, fine, fine, oh look, a line, absolute zero. Like the bunny rabbits hit an invisible property boundary and refused to cross because their lease agreement doesn’t cover the other side.”

  Chloe made a small noise of agreement.

  “He’s not wrong,” she said. “There’s no avoidance band. It’s all or nothing. That suggests zoning, not behavior.”

  “Containment corridors,” Trevor said under his breath.

  We all looked at him.

  “Governance uses similar language for certain models,” he went on, jaw tight. “In urban planning sims. ‘Containment corridors’ to channel protest flows away from critical infrastructure. Or to keep… high-risk populations away from each other.”

  “You’re saying this city does crowd control for its wildlife,” Frankie said. “And for whatever that—” he gestured vaguely toward the red zones “—is.”

  “I am saying,” Trevor said, “that whoever designed this place thought like an administrator.”

  Mercy dimmed the map’s colors, leaving only the faint ring of ecological quarantine corridors and the blank holes inside.

  “I still do not know what moves in those inner sectors,” she said. “But the pattern is clear. We are being geofenced away from them.”

  “VIP terrarium pass,” Frankie said, half under his breath.

  I groaned.

  “Do not call it that,” I said.

  “That’s absolutely what it is,” he said, brightening a little despite everything. “We are in the section marked ‘valued guests.’ Whatever’s out there is in ‘hazard remediation.’”

  “Or we’re in ‘specimen library’ and it’s in ‘pest control,’” Chloe said.

  “Comforting,” I said. “Thank you for that.”

  The light-rivers along our terrace brightened by a notch, washing the shelter in soft color. Somewhere up in the dome ribs, field lines shifted with a barely-audible groan.

  “Mercy?” I said.

  “Yes?”

  “We’re with you,” I said. “Whatever the city thinks it’s doing with your old chassis, whatever’s stomping through its private murder hallways… we’re with you. Not with it.”

  There was a tiny pause.

  “I know,” she said. “Rationally. My affect layer is… slower to update.”

  “Join the club,” Frankie said gently. “My affect layer has been screaming for eight hours straight.”

  “Same,” Chloe said.

  Trevor looked like he wanted to say something and couldn’t quite find words that didn’t sound like a report.

  Instead, he reached out and tapped the edge of the projected map, zooming in on our little green bubble.

  “Okay,” he said. “We log what we saw. We catalog the tracks. We note that the prey distribution is wrong, that corridors are tagged for ecological quarantine, that something large is being swept along a path we’re not allowed to see.”

  He took a breath.

  “And then,” he said, “we plan tomorrow as if we intend to keep being allowed. Because I would very much like to stay on the ‘valued guests’ side of this arrangement.”

  “Seconded,” I said.

  “Reluctantly concurred,” Chloe said.

  “Yay,” Frankie whispered. “Group project.”

  Out beyond the terrace, the city hummed and glowed and rearranged itself, sweeping something big through a set of invisible tracks while keeping our little patch oddly safe and oddly small.

  Tracks in the dust.

  And none of them were ours.