"You came down a marked path with surface skin, surface shoes, surface timing, carrying a bag that says I have no idea what kind of place this is," Mara said. Her voice was low, clipped, each word pushed into place like a bolt. "So I'll ask plain. Are you bait, spy, or fool?"

Elias said, "Scientist."

Her face did not move. Then, very faintly, one corner of her mouth twitched. Not amusement. Recognition of a worse answer than the ones she'd offered.

Mara said, "That's just fool with schooling."

He opened his mouth, shut it again, then put a hand against the wall because the tunnel tilted under him for a second. She saw that. She also saw him straighten before she could comment.

"I came from above," he said. "Not from your above. From two centuries earlier, if you want the shortest version that still sounds insane. I arrived in the gardens by accident. The machine is there. Or was. I found the tower. I found the service systems. I found policy notes in a memory depot that say truth was managed on purpose. People are taken below. The city on the surface is not the city that runs anything."

"No," Mara said. "Really?"

He stared at her.

She started walking again. "Keep up. If you're lying, you're a bad liar. If you're telling the truth, you're a bigger problem."

He followed, forcing breath into the tight bands around his ribs. "You knew already."