"It’s all there," Sheffing said, keeping his eyes fixed on the softly glowing colored curves and speaking in a faraway voice. "Artificial black holes. . . . just switch ’em on and off to order."

The information did not come as a big surprise to Hunt. The Ganymeans had confirmed that the Shapieron’s drive had in fact achieved this, and Hunt and Shelling had talked about its theoretical basis on many occasions. "You’ve figured it out?" Hunt asked, slipping into a vacant chair and studying the display.

"We’re on our way, anyhow."

"Does it get us any nearer instant point-to-point transfers?" That was something the Ganymeans had not achieved, although the possibility was implicit in their theoretical constructs. Black holes distantly separated in normal space seemed to link up via a hyperrealm within which unfamiliar physical principles operated, and the ordinary concepts and restrictions of the relativistic universe simply didn’t apply. As the Ganymeans had agreed, the promises implied by this were staggering, but nobody knew how to turn them into realities yet.

"It’s in there," Shelling answered. "The possibility is in there, but there’s another side to it that bothers me, and it’s impossible to separate out."

"What’s that?" Hunt asked.

"Time transfers," Shelling told him. Hunt frowned. Had he been talking to anybody else, he would have allowed his skepticism to show openly. Shelling spread his hands and gestured toward the screen. "You can’t get away from it. If the solutions admit point-to-point transfers through normal space, they admit transfers through time too. If you could find a way of exploiting one, you’d automatically have a way of exploiting the other as well. Those matrix integrals are symmetric."

Hunt waited for a moment to avoid appearing derisive. "That’s too much, Paul," he said. "What happens to causality? You’d never be able to unscramble the mess."

"I know. . . . I know the theory sounds screwy, but there it is. Either we’re up a dead end and none of it works, or we’re stuck with both solutions."

They spent the next hour working through Shelling’s equations again but ended up none the wiser. Groups at Cal Tech, Cambridge, the Ministry of Space Sciences in Moscow, and the University of Sydney, Australia, had found the same thing. Obviously Hunt and Shelling were not about to crack the problem there and then, and Hunt eventually left in a very curious and thoughtful mood.

Back in his own office, he called Speehan at MIT, who turned out to have some interesting results from a simulation model of the climatic upheavals caused fifty thousand years earlier by the process of lunar capture. Hunt then took care of a couple of other urgent items that had come in that morning, and was just settling down to study the Livermore paper when Lyn called from Caldwell’s suite at the top of the building. Her face was unusually serious.

"Gregg wants you in on the meeting up here," she told him without preamble. "Can you get up right away?"

Hunt sensed that she was pushed for time. "Give me two minutes." He cut the connection without further ado, consigned Livermore to the uncharted depths of the Navcomms databank, told Ginny to consult Duncan if anything desperate developed during the rest of the day, and left the office at a brisk pace.

From the web of communications links interconnecting UNSA’s manned and unmanned space vehicles with orbiting and surface bases all over the solar system, to the engineering and research establishments at places such as Houston, responsibility for the whole gamut of Navcomms activities ultimately resided in Caldwell’s office at the top of the Headquarters Building. It was a spacious and opulently furnished room with one wall completely of glass, looking down over the lesser skyscrapers of the city and the ant colony of the pedestrian precincts far below. The wall opposite Caldwell’s huge curved desk, which faced inward from a corner by the window, was composed almost totally of a battery of display screens that gave the place more the appearance of a control room than of an office. The remaining walls carried a display of color pictures showing some of the more spectacular UNSA projects of recent years, including a seven-mile-long photon-drive star probe being designed in California and an electromagnetic catapult being constructed across twenty miles of Tranquilitatis to hurl lunar-manufactured structural components into orbit for spacecraft assembly.

Caldwell was behind his desk and two other people were sitting with Lyn at the table set at a T to the desk’s front edge when a secretary ushered Hunt in from the outer office. One of them was a woman in her mid- to late forties, wearing a high-necked navy dress that hinted of a firm and well-preserved figure, and over it a wide-collared jacket of white-and-navy check. Her hair was a carefully styled frozen sea of auburn that stopped short of her shoulders, and the lines of her face, which was not unattractive in a natural kind of way beneath her sparse makeup, were clear and assertive. She was sitting erect and seemed composed and fully in command of herself. Hunt had the feeling that he had seen her somewhere before.

Her companion, a man, was smartly attired in a charcoal three-piece suit with a white shirt and two-tone gray tie. He had a fresh, clean-shaven look about him and jet-black hair cut short and brushed flat in college-boy fashion, although Hunt put him at not far off his own age. His eyes, dark and constantly mobile, gave the impression of serving an alert and quick-thinking mind.

Lyn flashed Hunt a quick smile from the side of the table opposite the two visitors. She had changed into a crisp two-piece edged with pale orange and was wearing her hair high. She looked distinctly un-"groped."

"Vic," Caldwell announced in his gravelly bass-baritone voice, "I’d like you to meet Karen Heller from the State Department in Washington, and Norman Pacey, who’s a presidential advisor on foreign relations." He made a resigned gesture in Hunt’s direction. "This is Dr. Vic Hunt. We send him to Jupiter to look into a few relics of some extinct aliens, and he comes back with a shipful of live ones."

They exchanged formalities. Both visitors knew about Hunt’s exploits, which had been well publicized. In fact Vic had met Karen Heller once very briefly at a reception given for some Ganymeans in Zurich about six months earlier. Of course! Hadn’t she been the U.S. Ambassador to-France, wasn’t it, at the time? Yes. She was representing the U.S. at the UN now, though. Norman Pacey had met some Ganymeans too, it turned out-in Washington-but Hunt hadn’t been present on that occasion.

Hunt took the empty chair at the end of the table, facing along the length of it toward Caldwell’s desk, and watched the head of wiry, gray, crose-cropped hair while Caldwell frowned down at his hands for a few seconds and drummed the top of his desk with his fingers. Then he raised his craggy, heavily browed face to look directly at Hunt, who knew better than to expect much in the way of preliminaries. "Something’s happened that I wanted to tell you about earlier but couldn’t," Caldwell said. "Signals from the Giants’ Star started coming in again about three weeks ago."

Even though he should have known about such a development if anyone did, Hunt was too taken aback for the moment to wonder about it. As months passed after the sole reply to the first message transmitted from Giordano Bruno at the time of the Shapieron’s departure, he had grown increasingly suspicious that the whole thing had been a hoax-that somebody with access to the UNSA communications net had somehow arranged a message to be relayed back from some piece of UNSA hardware located out in space in the right direction. He was open-minded enough to admit that with an advanced alien civilization anything could be possible, but a hoax had seemed the most likely explanation for the fourteen-hour turn-around time. If Caldwell were right, it made so much nonsense of that conviction.