Paul looked at Wojo's grizzled face. He's being extra cautious, and he's right to look at it that way. This is so new that nobody's had any experience with it.

But he said, "Look, Wojo, if these nanobugs work we can turn this set of tin cans into a regular palace in a couple of years. Moonbase can start making profits right away."

"But if it doesn't work-"

"That's why we're conducting the demonstration at a remote site," Paul said, with growing irritation. "If anything goes wrong, it'll go wrong out there and won't threaten the base here."

Wojo nodded solemnly. "It'll go wrong out there, all right. With you and me twenty miles from help."

"We'll have a hopper, for chrissake," Paul snapped. "We could jump all the way back here in fifteen minutes, if we had to."

Wojo nodded. "I suppose that's true," he said. But he didn't sound as if his heart was in it.

Nettled by Wojo's worries, Paul spent that whole afternoon deep in conference with Kris Cardenas, back at San Jose.

Sitting on his bunk, Paul said to her image in his laptop screen, "You can see why some of the people here are scared of the whole idea."

"Well," she admitted grudgingly, "the nanomachines are the size of viruses. They can be carried by air currents and float around. But the Moon's airless, so-"

"The interiors of our habitation modules aren't airless," Paul pointed out.

"Yes, but you're not using the bugs in your habitation modules, are you?" Cardenas replied sharply, her blue eyes snapping. "You're only using them out in the remote site, twenty miles from the nearest existing shelter."

"That's true, "Paul agreed.

"So there shouldn't be any trouble. Even if there is, once daylight comes up the bugs will overheat and shut down."

"Can they last fourteen days in a dormant condition?"

"For sure," she said. "But in fourteen days you ought to be able to sweep them all up."

"Paul nodded. "I guess so."

Cardenas smiled prettily. "Believe me, Mr. Stavenger, we've gone through every possible scenario in our simulations. We even rented the big vacuum chamber over at Ames to simulate the lunar environment. Nothing's going to go wrong."

"I guess so," Paul said again.

"Mr. Masterson has been here half a dozen times, checking out every facet of the experiment," she added.

"Greg?"

"Yes. He's triple-checked everything. And then some."

"That's good," Paul said lamely, adding to himself, I suppose.

But he went hunting through the underground shelters for Lana Goodman. Moonbase's so-called permanent resident was a smart scientist, Paul knew, and had no axe to grind in the matter of nanotechnology.

He found her in the photo lab that she had crammed into the minimal space between the laundry and the shower facility.

"Nanomachines?" Goodman was peering at a strip of film through a magnifying glass. Paul saw her elfin features in profile. With the light behind her, her thinning gray hair looked almost like a halo.

Paul explained what he was trying to do, and Wojo's apprehensions.

Goodman put the film down and turned her full attention to him. "I don't know the details, but I've heard a lot about nanotechnology. Mostly wild claims by enthusiasts and equally wild predictions of disaster by opponents."

Spreading his hands, Paul said, "Well, that's what I'm faced with: either the salvation of Moonbase or a disaster. I'd like your opinion on which to expect."

"Most of what I've read about deals with the medical applications," Goodman said, threading the film into the developing machine.

"Medical?"

"You know, an old lady like me gets interested in nano-machines that can keep the estrogen flowing." She winked broadly.

"Oh," said Paul. "I get it."

More seriously, she asked, "If these nanomachines don't work, are you going to close down Moonbase?"

"I don't want to do that," Paul said.

"I don't want to go back Earthside," said Goodman. "So maybe I'm not as unbiased in this matter as you think."

Scientists! Paul fumed inwardly. They never give you a straight answer. Always hedging everything with all kinds of qualifications and escape hatches. He remembered a professor of economics who complained that the government always looked for 'one-armed' advisors: those who wouldn't qualify everything by saying, "On the other hand..."

"Look," he said, "all I want is your honest opinion about'twhether or not it's safe to try this demonstration."

Goodman looked up at him. "Twenty miles out on the other side of the ringwall?"

"Twenty-five miles, actually. The site is twenty miles out on the mare from Tempo Nineteen."

"That should be far enough," Goodman said. "If anything does go wrong, it shouldn't affect us here."

That was what Paul wanted to hear.

But before he could thank her, Goodman said, "Let me think about it, though. Ask some people I know about it. If I come up with any problems, I'll let you know."

"We're leaving tomorrow morning," Paul said.

"Who's going with you?"

"Wojo."

Goodman grinned maliciously. "Good. He's a cantankerous old brute."

"You two don't get along?"

"I've been chasing his bod for months now, and he keeps eluding me. I think he's scared of me."

"Wojo?"

"Maybe he's still a virgin."

Paul stared at her for a stunned moment, not knowing whether she was serious or joking.

"Life's not easy up here for a horny old lady," Goodman said, with only the slightest of smiles. "Lots of nice young men, but they look on me like their grandmother. Wojo's more my age."

"Yeah," Paul said weakly. "I suppose he is."

Then he beat a hasty retreat, leaving Goodman grinning at his departing back.

TRACTOR FOUR.

Paul was surprised to see Hi Tinker suiting up in the preparation chamber next to the airlock.

Three walls of the cubicle were lined with spacesuits standing on racks like displays of medieval armor. Helmets rested on shelves just above the empty suit torsos, boots on the plastic flooring next to the leggings.

Tink was already in his leggings and boots when Paul came in. He was an amiable Canadian from Toronto, lean and lantern-jawed, with a dry sense of humor and a maddening propensity for puns.

With a lopsided smile he told Paul, "Wojo's outside already, checking out the tractor."

"Good," said Paul, going to the medium-sized suits.

"These nanomachines really worry him, you know." Before Paul could reply he went on, "You might say the bugs are bugging him."

Paul ignored the pun. No sense encouraging the man. "What're you suiting up for?" he asked, stepping into the leggings of the newest-looking suit he could find in his size.

I'm going with you"

"You are?"

Tinker nodded. "You can use a third set of hands to set things up, and I want to scout the territory out on the mare for a telescope site."

"What's wrong with siting a telescope here, inside the ringwall?"

"Too much radio chatter in here. I've got a grant from Caltech to look into developing a major radio telescope facility up here. It'll need someplace nice and quiet in the radio frequencies. A dome away from home."

Why wasn't I told about this? Paul asked himself. Tinker was a consultant, not a regular corporate employee. He came up to Moonbase every three months to check out the astronomical equipment that the base operated for a consortium of universities. Still, Paul thought, if he's won a grant from Caltech I should have been informed.

Then he realized that he was the CEO now, too far above the ranks to be involved in such details. The thought stung him. Paul wanted to know every detail about Moonbase.

Aloud, he said, "Farside would be the best place for radio quiet."

Lifting his suit's torso over his head, Tinker wormed his arms into its sleeves and popped his head up through the metal ring of its collar.

With a grunt that might have been part laugh, he said, "You know that, and I know that, and even Wojo knows that But find me a university that's got the money to build a base on the farside."

"What about the consortium?" Paul asked.

Tink shook his head sadly. "Not even the entire International Astronomical Union can raise that kind of cabbage. When it comes to finances, astronomers are at the end of the line."

Paul nodded, realizing that Tinker didn't make puns about his work. Be thankful for small mercies, he thought The two men checked out each other's suits and backpacks, then Paul followed Tink through the airlock and out onto the surface of the crater Alphonsus.

"Magnificent desolation," Paul murmured, as he always did when he went outside.

The tired, worn ringwall mountains rose above them as far as the eye could see. Alphonsus was so wide that Paul could barely make out the tops of the peaks at the center of the crater poking above the horizon. The crater floor, cracked and rilled, seemed as dead and untouched as the first time Paul had landed here. Except for the humps of rubble marking the buried modules of the base and the angular metal framework of the oxygen plant off to the right. The ground was welted with bright cleated trails that the tractors left.

As Paul stood there, though, he saw what Moonbase could become: a whole city, domed and covered with protective rubble, to be sure, but a real city of thousands of people with open spaces beneath its wide dome and green trees and plants and grass, soaring pillars and winding footpaths and broad windows so you could look outside and see the solar energy farms and the factories open to vacuum and the spaceport where ships landed and took off on a regular schedule.

"We're ready whenever you are, boss-man."

Wojo's voice in his earphones startled Paul out of his daydream. Turning, he saw the man standing by the tractor hatch. Wojo's spacesuit looked hard-used, grimy, its helmet scratched and dulled.

"Yeah," he said tightly. "Let's get going."

It was considerably less than comfortable sitting squeezed together in the tractor's cab inside their cumbersome space-suits, but Paul knew that a stray meteoroid could crack the canopy and the cab would lose its air in seconds.

The tractor's cab was a bubble of tempered plastiglass, pressurized to the same five pounds per square inch as the spacesuits, so that in an emergency the occupants could slam down their visor helmets and go to their suit life-support systems without needing time to prebreathe low-pressure oxygen to avoid the bends.

The underground shelters also ran at five psi, for the same reason. The 'air' that the Moonbase inhabitants breathed with seventy-two percent oxygen, twenty-eight percent nitrogen. The oxygen came from the lunar regolith; until they drilled successfully for ammonia the nitrogen had to be carried up from Earth.

One of the ongoing research efforts at the base was aimed at producing a metallic glass that had the transparency of good crystal and the structural strength of steel. Someday we'll be able to ride these buggies in our shirtsleeves, Paul told himself. In the meantime, it felt reassuring to have the bulk of the spacesuit protecting him, comfort be damned. There was only one chance in a trillion of being hit by a meteoroid big enough to crack the canopy, but Paul had no desire to test the odds.

The tractor climbed laboriously up the ringwall mountain over the easiest slope, which Wojo insisted on calling 'Wodjohowitcz Pass."

"Your name is too tough to spell for it to be used on maps," Tinker said archly. "It'll never pass the spelling test."

Paul groaned. Wojo muttered.

Paul took over the driving chores once they got down onto the flat of Mare Nubium. Wojo stopped the tractor so they could shift places, then when they were underway again he reached carefully behind their seats and pulled out three prepackaged lunches.

"Best sandwiches this side of Chattanooga," Wojo said proudly. "Made 'em myself."

Paul had to admit that they were good. One thing he had insisted on for Moonbase was top-quality food. We have to breathe recycled air and drink recycled water, but by God we'll eat decently, at least.

"Sandwiched the lunch chore in between your other duties?" Tinker punned.

It's going to be a long three days, Paul thought. Very long.

"Coming up on Shelter Nineteen," Wojo called out, one gloved finger on the map readout glowing in the control panel's main display screen.

The man's breath stinks, Paul said to himself.

Looking straight ahead, searching for the red light atop the antenna that marked the heaped rubble mound of the shelter, Paul asked, "What the hell are you drinking, Wojo?"

"What do you mean?"

"Water wouldn't give you a breath like that."

With great dignity, Wojo asked, "Are you implying that I have imbibed an alcoholic beverage?"