Martin buttered and chewed his toast, and finally interrupted: "You're a team. Is that it?"

"Right," said two Johns.

"God, what a team! I hadn't seen the point. How much do you each know what the others are thinking?"

"Not at all, properly speaking," replied one of the girls, Zayin. The others watched her with the proprietary, approving look they had. "No ESP, nothing fancy. But we think alike. We have exactly the same equipment. Given the same stimulus, the same problem, we're likely to be coming up with the same reactions and solutions at the same time. Explanations are easy—don't even have to make them, usually. We seldom misunderstand each other. It does facilitate our working as a team."

"Christ yes," said Martin. "Pugh and I have spent seven hours out of ten for six months misunderstanding each other. Like most people. What about emergencies, are you as good at meeting the unexpected problem as a nor ... an unrelated team?"

"Statistics so far indicate that we are," Zayin answered readily. Clones must be trained, Pugh thought, to meet questions, to reassure and reason. All they said had the slightly bland and stilted quality of answers furnished to the Public. "We can't brainstorm as singletons can, we as a team don't profit from the interplay of varied minds; but we have a compensatory advantage. Clones are drawn from the best human material, individuals of IIQ 99th percentile, Genetic Constitution alpha double A, and so on. We have more to draw on than most individuals do."

"And it's multiplied by a factor of ten. Who is—who was John Chow?"

"A genius surely," Pugh said politely. His interest in cloning was not so new and avid as Martin's.

"Leonardo Complex type," said Yod. "Biomath, also a cellist, and an undersea hunter, and interested in structural engineering problems, and so on. Died before he'd worked out his major theories."

"Then you each represent a different facet of his mind, his talents?"

"No," said Zayin, shaking her head in time with several others. "We share the basic equipment and tendencies, of course, but we're all engineers in Planetary Exploitation. A later clone can be trained to develop other aspects of the basic equipment. It's all training; the genetic substance is identical. We areJohn Chow. But we were differently trained."

Martin looked shell-shocked. "How old are you?"

"Twenty-three."

"You say he died young— Had they taken germ cells from him beforehand or something?"

Gimel took over: "He died at twenty-four in an aircar crash. They couldn't save the brain, so they took some intestinal cells and cultured them for cloning. Reproductive cells aren't used for cloning since they have only half the chromosomes. Intestinal cells happen to be easy to despecialize and reprogram for total growth."

"All chips off the old block," Martin said valiantly. "But how can . . . some of you be women . . . ?"

Beth took over: "It's easy to program half the clonal mass back to the female. Just delete the male gene from half the cells and they revert to the basic, that is, the female. It's trickier to go the other way, have to hook in artificial Y chromosomes. So they mostly clone from males, since clones function best bisexually."

Gimel again: "They've worked these matters of technique and function out carefully. The taxpayer wants the best for his money, and of course clones are expensive. With the cell-manipulations, and the incubation in Ngama Placentae, and the maintenance and training of the foster-parent groups, we end up costing about three million apiece."

"For your next generation," Martin said, still struggling, "I suppose you . . . you breed?"

"We females are sterile," said Beth with perfect equanimity; "you remember that the Y chromosome was deleted from our original cell. The males can interbreed with approved singletons, if they want to. But to get John Chow again as often as they want, they just reclone a cell from this clone."

Martin gave up the struggle. He nodded and chewed cold toast. "Well," said one of the Johns, and all changed mood, like a flock of starlings that change course in one wingflick, following a leader so fast that no eye can see which leads. They were ready to go. "How about a look at the mine? Then we'll unload the equipment. Some nice new models in the roboats; you'll want to see them. Right?" Had Pugh or Martin not agreed they might have found it hard to say so. The Johns were polite but unanimous; their decisions carried. Pugh, Commander of Libra Base 2, felt a qualm. Could he boss around this superman-woman-entity-of-ten? and a genius at that? He stuck close to Martin as they suited for outside. Neither said anything.

Four apiece in the three large jetsleds, they slipped off north from the dome, over Libra's dun rugose skin, in starlight.

"Desolate," one said.

It was a boy and girl with Pugh and Martin. Pugh wondered if these were the two that had shared a sleeping-bag last night. No doubt they wouldn't mind if he asked them. Sex must be as handy as breathing, to them. Did you two breathe last night?

"Yes," he said, "it is desolate."

"This is our first time Off, except training on Luna." The girl's voice was definitely a bit higher and softer.

"How did you take the big hop?"

"They doped us. I wanted to experience it." That was the boy; he sounded wistful. They seemed to have more personality, only two at a time. Did repetition of the individual negate individuality?

"Don't worry," said Martin, steering the sled, "you can't experience no-time because it isn't there."

"I'd just like to once," one of them said. "So we'd know."

The Mountains of Merioneth showed leprotic in starlight to the east, a plume of freezing gas trailed silvery from a vent-hole to the west, and the sled tilted groundward. The twins braced for the stop at one moment, each with a slight protective gesture to the other. Your skin is my skin, Pugh thought, but literally, no metaphor. What would it be like, then, to have someone as close to you as that? Always to be answered when you spoke, never to be in pain alone. Love your neighbor as you love yourself. . . . That hard old problem was solved. The neighbor was the self: the love was perfect.

And here was Hellmouth, the mine.

Pugh was the Exploratory Mission's ET geologist, and Martin his technician and cartographer; but when in the course of a local survey Martin had discovered the U-mine, Pugh had given him full credit, as well as the onus of prospecting the lode and planning the Exploitation Team's job. These kids had been sent out from Earth years before Martin's reports got there, and had not known what their job would be until they got here. The Exploitation Corps simply set out teams regularly and blindly as a dandelion sends out its seeds, knowing there would be a job for them on Libra or the next planet out or one they hadn't even heard about yet. The Government wanted uranium too urgently to wait while reports drifted home across the light-years. The stuff was like gold, old-fashioned but essential, worth mining extra-terrestrially and shipping interstellar. Worth its weight in people, Pugh thought sourly, watching the tall young men and women go one by one, glimmering in starlight, into the black hole Martin had named Hellmouth.

As they went in their homeostatic forehead-lamps brightened. Twelve nodding gleams ran along the moist, wrinkled walls. Pugh heard Martin's radiation counter peeping twenty to the dozen up ahead. "Here's the dropoff," said Martin's voice in the suit intercom, drowning out the peeping and the dead silence that was around them. "We're in a side-fissure; this is the main vertical vent in front of us." The black void gaped, its far side not visible in the headlamp beams. "Last vulcanism seems to have been a couple of thousand years ago. Nearest fault is twenty-eight kilos east, in the Trench. This region seems to be as safe seismically as anything in the area. The big basalt-flow overhead stabilizes all these substructures, so long as it remains stable itself. Your central lode is thirty-six meters down and runs in a series of five bubble-caverns northeast. It is a lode, a pipe of very high-grade ore. You saw the percentage figures, right? Extraction's going to be no problem. All you've got to do is get the bubbles topside."