"Could be. Insufficient data. If it's true, it's all the more reason to warn Earth. But Ridgeback is doomed."

Jerry had his mother's hair, sunbleached auburn. He had too much of it. On his narrow forehead it merged with his brows . . . his shelf of brow, and the brown eyes watching from way back. He hardly needed the shorts he was wearing; the hair would have been almost enough. He was nearly three.

He seemed to sense something wrong between his parents. He would spend some minutes scampering through the grove of sapling fruit trees, agile as a child twice his age; then suddenly return to take their hands and try to tug them both into action.

Doc thought of the frozen fertilized eggs of dogs in storage. Jerry with a dog . . . the thought was repulsive. Why? Shouldn't a child have a dog?

"Well, of course I guessed something" Elise said bitterly. "You were always in the library. When you were home, the way that you looked at Jerry . . . and me, come to think of it. I see now why you haven't taken me to bed much lately." She'd been avoiding his eyes, but now she looked full at him. "I do see. But, Harry, couldn't you have asked me for help? I have some medical knowledge, and, and I'm your wife, and Jerry's mother, d.a.m.n it Harry!"

"Would you believe I didn't want you worrying?"

"Oh, really? How did it work?"

Her sarcasm cut deep. Bleeding, he said, "Nothing worked."

Jerry came out of the trees at a tottering run. Doc stood up, caught him, swung him around, chased him through the trees . . . caine back puffing, smiling, holding his hand. He almost lost the smile, but Elise was smiling back, with some effort. She hugged Jerry, then pulled fried chicken from the picnic basket and offered it around.

She said, "That alien invasion idea is stupid."

"Granted. It'd be easy to think someone has 'done' it to us."

"Haven't you found anything? Isn't there anything I can help with?"

"I've found a lot. All the kids have a lower body temperature, two point seven degrees. They're healthy as horses, but h.e.l.l, who would they catch measles from? Their brain capacity is too small, and not much of it is frontal lobe. They're hard to toilet train and they should have started babbling, at least, long ago. What counts is the brain, of course."

Elise took one of Jerry's small hands. Jerry crawled into her lap and she rocked him. "His hands are okay. Human. His eyes . . . are brown, like yours. His cheekbones are like yours, too. High and a little rounded."

Doc tried to smile. "His eyes look a little strange. They're not really slanted enough to suspect mongolism, but I'll bet there's a gene change. But where do I go from there? I can see differences, and they're even consistent, but there's no precedent for the a.n.a.lysis equipment to extrapolate from." Doc looked disgusted. Elise touched his cheek, understanding.

"Can you teach me to use an electron microscope?"

Doc sat at the computer console, watching over Jill's shoulder as she brought out the Orion vehicle's image of Ridgeback. The interstellar s.p.a.cecraft doubled as a weather eye, and the picture, once drab with browns and grays, now showed strips of green beneath the fragmented cloud cover. If Ridgeback was dead, it certainly didn't show on the screen.

"Well, we've done a fair old job." Jill grinned and took off her headset. Her puffy natural had collected dust and seeds and vegetable fluff until she gave up and shaved it off. The tightly curled mat just covered her scalp now, framing her chocolate cameo features. "The cultivated strip has spread like weeds. All along the continent now I get CO2-oxygen exchange. It jumped the ridges last year, and now I get readings on the western side."

"Are you happy?"

"No," she said slowly. "I've done my job. Is it too much to want a child too? I wouldn't care about the . . . problem. I just want . .

"It's n.o.body's fault," Doc said helplessly.

"I know, I know. But two miscarriages. Couldn't they have known back on Earth? Wasn't there any way to be sure? Why did I have to come all this way . . ." She caught herself and smiled thinly. "I guess I should count my blessings. I'm better off than poor Angie."

"Poor Angie," Doc echoed sadly. How could they have known about Chris? The night Doc announced his conclusions about the children, there had been tears and harsh words, but no violence. But then there was Chris.

Chris, who had wanted a child more than any of them could have known. Who had suffered silently through Angie's first miscarriage, who hoped and prayed for the safe delivery of their second effort.

It had been an easy birth.

And the morning after Doc's speech, the three of them, Chris, Angie and the baby, were found in the quiet of their stone house, the life still ebbing from Chris' eyes and the gaps in his wrists.

"I'm sorry," he said over and over, shaking his head as if he were cold, his watery brown eyes dulling. "I just couldn't take it. I just . . . I just . . ." and he died. The three of them were buried in the cemetery outside of town, without coffins.

The town was different after the deaths, a stifling quiet hanging in the streets. Few colonists ate at the communal meals, choosing to take their suppers at home.

In an effort to bring everyone together, Jase encouraged them to come to town hall for Movie Night.

The film was "The Sound of Music." The screen erupted with sound and color, dazzling green Alps and snow-crested mountains, happy song and the smiling faces of normal, healthy children.

Half the colonists walked out.

Most of the women took contraceptives now, except those who chose not to tamper with their estrogen balance. For these, Doc performed painless menstrual extractions bimonthly.

Nat and Elise insisted on having more children. Maybe the problem only affected the firstborn, they argued. Doc fought the idea at first. He found himself combatting Brew's sullen withdrawal, Nat's frantic insistence, and a core of hot anger in his own wife.

Earth could find a cure. It was possible. Then their grandchildren would be normal again, the heirs to a world.

He gave in.

But all the children were the same. In the end, Nat alone had not given up. She had borne five children, and was carrying her sixth.

The message of failure was halfway to Earth, but any reply was still nineteen years away. Doc had adapted the habit of talking things over with Jase, hoping that he would catch some glimpse of a solution.

"I still think it's a disease," he told Jase, who had heard that before, but didn't mention it. The bay was quiet and their lines were still. They talked only during fishing trips. They didn't want the rest of the colony brooding any more than they already were. "A mutant virus. But I've been wondering, could the changes have screwed us up? A shorter day, a longer year, a little heavier gravity. Different air mixture. No common cold, no mosquito bites; even that could be the key."

On a night like this, in air this clear, you could even see starglades casting streaks across the water. A fish jumped far across the bay, and phosph.o.r.escence lit that patch of water for a moment. The Orion vehicle, mace-shaped, rose out of the west, past the blaze of the Pleiades. Roy would be rendezvousing with it now, preparing for tomorrow's Year Day celebration.

Jase seemed to need these trips even more than Doc. After the murders the life seemed to have gone out of him, only flashes of his personality coming through at tranquil times like these. He asked, "Are you going to have Jill breed mosquitoes?"

Yes."

"I think you're reaching. Weren't you looking at the genes in the cytoplasm?"

"Yeah. Elise's idea, and it was a good one. I'd forgotten there were genes outside the cell nucleus. They control the big things, you know: not the shape of your fingers, but how many you get, and where. But they're hard to find, Jase. And maybe we found some differences between our genes and the children's, but even the computer Doesn't know what the difference means."

"Mosquitoes." Jase shook his head. "We know there's a fish down that way. Shall we go after him?"

"We've got enough. Have to be home by morning. Year Day."

"What exactly are we celebrating this time?"

"h.e.l.l, you're the mayor. You think of something." Doc sulked, watching the water ripple around his float. "Jase, we can't give up-"

Jase's face was slack with horror, eyes east up to the sky. Doc followed his gaze, to where a flaring light blossomed behind the Orion s.p.a.cecraft.

"Oh my G.o.d," Jase rasped, "Roy's up there."

Throwing his bamboo pole in the water, Jase started the engine and raced for sh.o.r.e.

Doc studied the readouts carefully. "Mother of G.o.d," he whispered. "How many engines did he fire?"

"Six." Jill's eyes were glued to the screen, her voice flat. "If he was aboard, he . . . well, there isn't much chance he survived the acceleration. Most of the equipment up there must be junk now."

"But what if he did survive? Is there a chance?"

"I don't know. Roy was getting set to beam the messages down, but saidthat he had an alarm to handle first. He went away for a while, and ." she seemed to search for words. She whispered, "Boom."

"If he was outside the ship, in one of the little rocket sleds, he could get to the shuttle vehicle."

Jase walked heavily into the lab.

"What about Cynnie? What did she say?" Doc asked quickly.

Jase's face was blank of emotion. "She talked to him before the accident."

"And?"

"It's all she would say. I'm afraid she took it pretty bad. This was sort of the final straw." His eyes were hollow as he reminisced. "She was always a brave kid, you know? Anything I could do, she'd be right behind me, measuring up to big brother. There's just a limit, that's all. There's just a limit."

Doc's voice was firm, only a slight edge of unease breaking through his control. "I think we had better face it. Roy is dead. The Orion's ruined, and the shuttle-craft is gone anyway."

"He could be alive . . ." Jifi ventured.

Doc tried to take the sting out of his voice, and was not entirely successful. "Where? On the ship, crushed to a paste? Not on the shuttle. It's tumbling further from the Orion every second. There's no one on it. In one of the rocket sleds?" His face softened, and they could see that he was afraid to have hope. "Yes. Maybe that. Maybe on one of the sleds."

They nodded to each other, and they and the other colonists spent long hours on the telescope hoping, and praying.

But there was nothing alive up there now. Ridgeback was entirely alone.

Cynnie never recovered. She would talk only to her brother, refusing even to see her child. She was morose and ate little, spending most of her time watching the sky with something like terrified awe in her eyes.

And one day, seven months after the accident, she walked into the woods and never returned.

Doc hadn't seen Jerry for three weeks.

The children lived in a community complex which had some of the aspects of a boarding school. The colonists took turns at nursing duty. Jill spent most of her time there since she and Greg were on the outs. Lately, Elise had taken up the habit too. Not that he blamed her; he couldn't have been very good company the last few months.

Parents took their children out to the T-shaped complex whenever they felt like it, so that some of the children had more freedom than others. But by and large they all were expected to live there eventually.

Brew was coming out of the woods with a group of six children when Doc stumbled out into the sunlight and saw Jerry.

He wore a rough pair of coveralls that fit him well enough, but he would have looked ludicrous if there had been anything to laugh about. Soft brown fur covered every inch of him. As Doc appeared he turned his head with a bird-quick movement, saw his father, and scampered over. Jerry bounced into him, wrapped long arms tight about his rib cage and said, eagerly, "Daddy."

There was a slight pause.

"h.e.l.lo, Jerry." Doc slowly bent to the ground, looking into his son's eyes.

"Daddy Doc, Daddy Doc," he chattered, smiling up at his father. His vocabulary was about fifteen words. Jerry was six years old and much too big for his age. His fingers were very long and strong, but his thumbs were small and short and inconsequential. Doc had seen him handle silverware without much trouble. His nose pugged, jaw ma.s.sive with a receding chin. There were white markings in the fur around his eyes, accentuating the heavy supraorbital ridges, making the poor child look like- The poor child. Doc snorted with self-contempt. Listen to me. Why not my child?

Because I'm ashamed. Because we lock our children away to ease the pain. Because they look like- Doc gently disengaged Jerry's fingers from his shirt, turned and half-ran back to the ship. Shivering, he curled up on one of the cots and cursed himself to sleep.

Hours later he roused himself and, woozy with fatigue, he went looking for Jase. He found him on a work detail in the north fields, picking fruit.

"I'm not sure," he told Jase. "They're not old enough for me to be sure. But I want your opinion."

"Show me," said Jase, and followed him to the library.

The picture on the tape was an artist's rendering of Pithecanthropus ereetus. He stood on a gra.s.sy knoll looking warily out at the viewer, his long-fingered hand clutching a sharp-edged throwing rock.

"I'll smack your head," said Jase.

"I'm wrong, then?"

"You're calling them apes!"

"I'm not. Read the copy. Pithecanthropus was a small-brained Pleistocene primate, thought to be a transitional stage between ape and man.

You got that? Pith is also called Java Man."

Jase glared at the reader. "The markings are different. And there is the fur-"

"Forget 'em. They're nothing but guesswork. All the artist had to go on were crumbling bones and some broken rocks."

"Broken rocks?"

"Pith used to break rocks in half to get an edged weapon. It was about the extent of his tool-making ability. All we know about what he looked like comes from fossilized bones-very much like the skeleton of a stoop shouldered man with foot trouble, topped with the skull of an ape with hydrocephalus."

"Very nice. Will Eve's children be fish?"

"I don't know, dammit. I don't know anything at all. Look, Pith isn't the only candidate for missing link. h.o.m.o Habilis looked a lot more like us and lived about two million years ago. Kenyapithicus Africa.n.u.s resembled us less, but lived eighteen million years earlier. So I can't say what we've got here. G.o.d only knows what the next generation will be like. That depends on whether the children are moving backwards or maybe sideways. I don't know, Jase, I just don't know!" The last words were shrill, and Doc punctuated them by slamming his fist against a wire window screen. Then, because he could think of nothing more to say, he did it again. And again. And- Jase caught his arm. Three knuckles were torn and bleeding. "Get some sleep," he said, eyes sad. "I'll have them send Earth a description of Eve the way she is now. She's oldest, and best developed. We'll send them all we have on her. It's all we can do."

Momentum and the thoroughness of their training had kept them going for eight years. Now the work of making a world slowed and stopped.

It didn't matter. The crops and the meat animals had no natural enemies on Ridgeback. Life spread along the continent like a green plague.

Already it had touched some of the islands.

Doc was gathering fruit in the groves. It was a shady place, cool, quiet, and it made for a tranquil day's work. There was no set quota. You took home approximately a third of what you gathered. Sometimes he worked there, and sometimes he helped with the cattle, examining for health and pregnancy, or herding the animals with the nonlethal sonic stunners.

He wished that Elise were here with him, so they could laugh together, but that was growing infrequent now. She was growing more involved with the nursery, and he spent little of his time there.

Jill's voice hailed him from the bottom of the ladder. "Hey up there, Doc. How about a break?"

He grinned and climbed down, hauling a sack of oranges.

"Tired of spending the day reading, I guess," she said lightly. She offered him an apple. He polished it on his shirt and took a bite. "Just needed to talk to somebody."

"Kinda depressed?"