A sign mounted on a chain blocked the passageway to vehicle traffic. Patricia read the sign after stopping the truck and setting the parking brake.

NO TRUCKS OR PEDESTRIANS BEYOND THIS POINT

BY ORDER OF Y. JACOB

DIRECTOR ARCHAEOLOGY TEAM

"And he means it, too," Takahashi said dryly. "That's virgin territory beyond that sign. They've checked over this building, and that's why we're allowed in—but don't touch."

They climbed up a meter-high ledge and stooped over to enter the hatchway. Recently installed locks and chains held more doors open. Patricia noticed other sensing devices—some covered with silvery tape—mounted on the walls, floor and ceiling.

"The machines would offload food, equipment, whatever the building needed through these halls. Automatic carts would deliver the goods to the appropriate chutes and they would lift them to different parts of the building. From this point on, though, we're not cargo; we're people."

Another open hatchway gave access to a large ground-floor reception area. Free-form seats and couches—apparently made of natural wood—furnished a sunken conversation pit near a broad, one-piece window that stretched at least twenty meters to the ceiling. A well-maintained flower garden stretched beyond the window. She was completely taken in by the illusion until she realized the garden was illuminated by sunlight and that blue sky showed through the trees. She stopped to stare and Takahashi waited patiently with hands folded.

"That's lovely," she said.

"The garden's real; the sunlight and sky are fake," he said noncommittally.

"I was wondering how they got along without sunshine and blue skies."

"If you went outside, you'd see the window's having us on."

"It looks very real."

The floor resembled shiny stonework but felt carpeted. Patricia shuffled her feet experimentally but her efforts produced no sound.

"Going up will take some will power," Takahashi warned. At the far end of the reception area were two open shafts sunk into the wall. "Not recommended for those with vertigo." They entered the left-hand shaft. Takahashi pointed down and reached out with his foot to tap a red circle on the floor. The circle glowed. "Seven," he said. "Both of us."

The floor receded. With no visible support, they flew up the shaft. Except for the appearance of motion there was no sensation whatsoever. Patricia's eyes widened and she reached for Takahashi's arm. Above the reception area, the shaft was featureless. There was no way of telling how many floors were passing.

"Only takes a second," he said. "Don't you love it? I don't know how many novels I've read with this sort of thing in them. In Thistledown City, it's real." This was the first time Patricia had heard him express delight. He seemed intensely interested in her reaction: Another spaghetti worm mystery, she thought. See how the girl screams.

She let go of his arm just as a portion of the shaft became transparent in front of them. They were smoothly, gently deposited on the floor beyond.