From the air, the Scottish Hill district looked like an ordinary suburb, but all its houses and stores had been empty for decades, sealed by near-invisible plastic skins which proofed their structures against decay. Most of Madison City was similarly deserted, similarly preserved, with time switches bringing on the street and house lights at dusk for the benefit of families who had long since emigrated to the Big O.

Reaching the edge of the museum district, Dallen turned the car into a cross-street and slowed down. He was less than a block away from 1990 Street itself and was entering the "living" sector of the permanent display. Solid images of cars and other vehicles — all of late 20th Century design — moved purposefully ahead of him, and seemingly real people in the costume of the period thronged the sidewalks and went in and out of stores.

The images had been closely packed to create an impression of overcrowded city life on Earth three centuries earlier, before the discovery of Orbitsville. Stationary cars formed a continuous line on each side of the street, apparently leaving no room for Dallen to park, but he knew the illusion was the least of his problems. He drove directly into a resplendent white Cadillac, unable to prevent himself flinching in the instant when the front of his own car burrowed into the convincingly real bodywork of the larger vehicle and braked sharply. Sounds and smells of Madison circa 1990, accurately reproduced by hidden machines, enveloped him as he got out of the car and began walking north towards the next intersection.

"Carry! 1 think we just got another whisper near the corner of 1990 and Third." The voice in Dallen's ear now had a discernible edge of nervousness. "He's getting too near the Exhibition Centre."

"I'm on First, turning into 1990 two blocks east of him," Dallen responded. "Assuming we walk about the same speed, that means we should meet up near the corner of Second. It shouldn't be too hard to pick him out. "Him or her."