He used the broken tile chip to scrape a black resin-soot smear from the inside seam of the box and rub it over the polymer, pulling up the raised print and old stamp marks beneath it. Crude, but enough. His ribs burned from the crouch. Sweat slipped down his spine despite the cool draft creeping in from the dead side aisle.

Mara kept watch, knife low in one hand, a bundle of papers in the other. “This is your sickness,” she said without looking back. “World ending at your feet and you still want neat evidence.”

He almost answered with anger. What came out was flatter than he expected. “If I die with a story, they bury a story. If I die with this, someone else can still open it.”

That landed. Not peace, but a stop.

Lina crouched beside him, scanning the dark over his shoulder. “Fast,” she whispered. “The walls are listening.”

He made two rub copies, then tore free three original pages and shoved both copies and originals into the satchel. Mara looked ready to object again, but the conduit spared her the trouble. A long mournful call rolled through a vent pipe above them, almost musical, almost human. Lina went white.

“What is that?” Elias asked.

“Intake call,” Mara said. “Not real. Used to freeze kids and flush wanderers.”

Another side light winked out. Then another.