"I know," he said. "That is why it may still have old manual locks. Hinges. Latches. Striker plates. Things a person can force."

Lina shook her head, not arguing with the logic, which somehow made it worse. "Dark keeps things. It does not give well."

"Then wait near the open strip," he said. "If I am not back before the route tones change twice, leave."

She stared at him so long he almost looked away first. "I will not leave."

He wanted to tell her that waiting here was still a kind of leaving. He wanted to tell her she should be somewhere with light and food and those soft routines that had shaped her whole life. What came out was thinner.

Elias said, "Then stay where you can see the sky."

Now, hours later—after one route-tone change and the long approach toward a second—the sky showed only as a pale blade through broken roof sections. Mostly there was damp wall, old cable hum, and the soft drag of his own steps. Hunger had sharpened into something flat and mean. It hollowed him out and left him impatient with every sealed panel, every blocked junction, every wrong turn. Twice he followed painted arrows only to find collapsed sections with standing water at the base, black and still. Once he bent to check a side passage and the world tilted so hard he had to crouch, eyes shut, fingers digging into the rail until the wave passed.