Hall said, "What about the deleted passages?"

"Major Manchek at Vandenberg told me," Stone said, "that they had to do with the Russian craft in the area. The two stations eventually concluded that the Russians had not, either accidentally or purposely, brought down the Scoop satellite. No one has since suggested differently."

They nodded.

"It's tempting," Stone said. "The Air Force maintains a watchdog facility in Kentucky that tracks all satellites in earth orbit. It has a dual function, both to follow old satellites known to be in orbit and to track new ones. There are twelve satellites in orbit at this time that cannot be accounted for; in other words, they are not ours, and are not the result of announced Soviet launches. It is thought that some of these represent navigation satellites for Soviet submarines. Others are presumed to be spy satellites. But the important thing is that Russian or not, there are a hell of a lot of satellites up there. As of last Friday, the Air Force reported five hundred and eighty-seven orbiting bodies around the earth. This includes some old, nonfunctioning satellites from the American Explorer series and the Russian Sputnik series. It also includes boosters and final stages—anything in stable orbit large enough to reflect back a radar beam."

"That's a lot of satellites."

"Yes, and there are probably many more. The Air Force thinks there is a lot of junk out there—nuts, bolts, scraps of metal—all in more or less stable orbit. No orbit, as you know, is completely stable. Without frequent corrections, any satellite will eventually decay out and spiral down to earth, burning up in the atmosphere. But that may be years, even decades, after the launch. In any event, the Air Force estimates that the total number of individual orbiting objects could be anything up to seventy-five thousand."

"So a collision with a piece of junk is possible."

"Yes. Possible."

"How about a meteor?"

"That is the other possibility, and the one Vandenberg favors. A random event, most likely a meteor."

"Any showers these days?"

"None, apparently. But that does not rule out a meteor collision."

Leavitt cleared his throat. "There is still another possibility."

Stone frowned. He knew that Leavitt was imaginative, and that this trait was both a strength and a defect. At times, Leavitt could be startling and exciting; at others, merely irritating. "It's rather farfetched," Stone said, "to postulate debris from some extragalactic source other than—"

"I agree," Leavitt said. "Hopelessly farfetched. No evidence for it whatever. But I don't think we can afford to ignore the possibility."

A gong sounded softly. A lush female voice, which Hall now recognized as that of Gladys Stevens of Omaha, said softly, "You may proceed to the next level, gentlemen."

13. Level V

LEVEL V WAS PAINTED A QUIET SHADE OF BLUE, and they all wore blue uniforms. Burton showed Hall around.

"This floor," he said, "is like all the others. It's circular. Arranged in a series of concentric circles, actually. We're on the outer perimeter now; this is where we live and work. Cafeteria, sleeping rooms, everything is out here. Just inside is a ring of laboratories. And inside that, sealed off from us, is the central core. That's where the satellite and the two people are now."