"Because we're the closest, and we can improvise," Hall said. "We have some isolation facilities here."

"What are they used for, under normal circumstances?" Harry asked. He glanced at Arthur with an expression between roguishness and pique.

"I'm not at liberty to discuss that," Hall said, smiling slightly.

"It's what I thought," Harry said to Arthur. "Yes, indeed." He nodded and faced forward.

"What were you thinking, Mr. Feinman?" Colonel Hall asked, still smiling, albeit more tightly.

"We're moving biological weapons research into space, Harry said tersely." Automated modules controlled from Earth. Bring them back here, and they'll have to be isolated. Son of a bitch."

Hall's smile flickered but, to his credit, did not vanish completely. He had sprung his own trap. "I see," he said.

"We all have the highest clearances and presidential authorization," Arthur reminded him. "I doubt that there's anything we can be kept from knowing, if we press hard enough."

"I hope you appreciate our position here, Mr. Gordon, Mr. Feinman," Hall said. "This whole thing was tossed into our laps just a week ago. We haven't straightened out all of our security procedures, and it'll be some time before we decide who needs to know what."

"I would think this takes priority over practically everything," Arthur said.

"We're still not sure what we have here," Colonel Hall admitted. "Perhaps you gentlemen can help us clear up our priorities."

Arthur grimaced. "Now the ball's in our court," he said. "Touché, Colonel."

"Better your court than mine," Hall said. "This whole thing has been an administrative nightmare. We have four civilians and four of our own men in isolation. We have no warrants for arrest or any other formal papers, and there is no—well, you can imagine. We can only stretch national security so far."

"And the LGM?" Harry asked, turning back again.

"He's—it's—our star attraction. You'll see it first, then we'll interview the men who found it."

" 'It,' " Arthur said. "We'll have to find a less ominous name for that soon, certainly before 'it' becomes common knowledge."

"We've been calling it the Guest, with a capital g," Hall said. "It almost goes without saying, we'd like to avoid any leaks."

"Not likely to avoid it for long, with the Australians having gone public," Harry said.

Hall nodded, facing up to practicalities. "We still don't know whether they have what we have."

"What we have, the Russians probably already know about," Harry said.

"Don't be cynical, Harry," Arthur admonished.

"Sorry." Harry grinned boyishly at the officer beside him, Lieutenant Sanborn, and then at Hall. "But am I wrong?"

"I hope you are, sir," Sanborn said.

On a concrete apron a mile and a half from the shuttle runway stood an implacable concrete building with inward-sloping walls, covering about two acres of ground. The tops of the walls rose three stories above the surrounding plain of concrete and asphalt. "Looks like a bunker," Harry said as the bus approached a ramp inclining below ground level. "Built to withstand nuclear strike?"