"We saw you at Xingu. You're the Jamarik.u.ma. What are you doing here?"

"I'm here to help," said Maria.

"Help us do what?" said the old woman.

"You don't have to stay in this place," said Maria. "If you do, you and your children and your grandchildren's children won't ever be allowed to leave."

The old woman-and half a dozen other older members of the tribe-glanced at the Cure. Not in a particularly friendly way.

"What's this all about?" said the old woman to the Cure, still in Portuguese. "You've got a spirit arguing for you now?"He replied in their own language. To Maria he sounded sulky.

"Do you understand why you're here?" said Maria. "These people . . ." She gestured at the looming buildings. "They want your blood, your . . ."Genes might meansouls to them. "You have a-a talent to cure diseases," said Maria. "That's why they want your blood."

Guarded eyes stared back from around the fire.

The old woman nodded. "What's so bad about that?"

"You won't ever be able to go back home," said Maria.

The old woman snorted. "At home they were trying to shoot us." She spat into the fire. "We're afraid to go back there."

"Buthere we're animals." The Cure pushed himself to his feet. "We'reprisoners! "

"We've had this discussion," said the old woman sharply and turned to Maria. "We made a decision months ago. We said he didn't have to stay if he didn't want to, but he stayed anyway, and now he's bringing in spirits to make an argument that no one else agrees with. We're safer right here than we've been for years. No one's shooting at us. So we have to wear their ugly jewelry." She touched the ruby sampler in her ear. "So we lose a little blood now and then. It's just a scratch."

"But you're in a cage," said Maria.

"I don't like that part," said the old woman. "But you have to admit, it's a big cage, and mostly it keeps the bandits and murderers out."

The Cure jabbed a finger at Maria, making his point in harsh staccato tones. Maria only caught the word Xingu .

The old woman eyed Maria. "What would happen to us at Xingu?"

"We'd teach you how to be part of the world outside," said Maria. "We'd show you what you need to know to be farmers, or to live in the city if that's what you want."

"Are there guns in the world outside?"

It was a patronizing question. Maria felt sweat break out at the small of her back. "You know there are."

"Would we all be able to stay together, the entire tribe?" asked the old woman.

"We do the best we can," said Maria. "Sometimes it isn't possible to keep everyone together, but we try."

The old woman made a wide gesture into the dark. "We didn't lose one single person on the trip. You're saying you can't guarantee that for us at Xingu, though. Is that right?"

"Right," said Maria.

"But we'd be free."

Maria didn't say anything.

The old woman made a sharp gesture. "It's time for the Jamarik.u.ma spirit to leave. If that's what sheactually is." She closed her eyes and began to hum, a spirit-dismissing song, Maria supposed, and she glanced at the Cure, who leaped to his feet.

"I am leaving. With the Jamarik.u.ma."

The old woman nodded, still humming, as though she was glad he'd finally made up his mind.

The Cure took a step away from the fire. He walked-no, he sauntered around his silent friends, family, maybe even his wife. No one said anything and no one was shedding any tears. He came over to Maria and stood beside her.

"I will not come back," he said.

The old woman hummed a little louder, like she was covering his noise with hers.

When they got back to the Toyota, Maria unlocked the pa.s.senger side and let him in. He shut the door and she walked slowly around the back to give herself time to breathe. Her heart was pounding and her head felt empty and light, like she was dreaming. She leaned against the driver's side, just close enough to see his dim reflection in the side mirror. He was rubbing his sweaty face, hard, as though he could peel away his skin.

In that moment, she felt as though she could reach into the night, to just the right place and find an invisible door which would open into the next day. It was the results of a night with him that she wanted, she realized. He was like a prize she'd just won. For the first time, she wondered what his name was.

She pulled the driver's side open and got in beside him. She turned the key in the ignition and checked the rearview mirror as the dashboard lit up. All she could see of herself was a ghostly, indistinct shape.

"Is something wrong?" he asked.

"Everything's fine." She said and let the truck blunder forward into the insect-laden night.

Later, when the access road evened out to pavement, he put his hot palm on her thigh. She kept driving, watching how the headlights cut only so far ahead into the darkness. She stopped just before the main road, and without looking at him, reached out to touch his fingers.

"Are we going to Xingu?" he asked, like a child.

"No," she said. "I can't go back."

"Neither can I," he said, and let her kiss him. Here. And there.

JACK WILLIAMSON.

Jack Williamson is a marvel. There is simply no other word for him. The man has been delighting readers practically as long as science fiction has existed. When I first met Jack at a banquet in Lawrence, Kansas, I asked him about his earliest publication. He said, "Well, I published my first story in 1928.You were just a little girl." After I ran to the ladies' room to check in the mirror whether I'd really turned into my mother, I forgave him. I think Jack's sweetness and charm could get him forgiven anything.

Born in 1908, Jack lived in Mexico and West Texas before the family moved by covered wagon to a semidesert homestead in eastern New Mexico. He grew up there, escaping into his imagination via Jules Verne and other early SF. After three years of college, he dropped out to write science fiction, selling enough to keep himself alive until World War II. Back from service as a weather forecaster in the South Pacific, he wroteThe Humanoids , worked as a newspaper editor, created the comic stripBeyond Mars for theNew York Sunday News , earned a Ph.D. in English literature, and then taught at Eastern New Mexico University. Just your average normal life.

Jack still teaches one course a year while continuing to add to his oeuvre of fifty-odd novels. "The Ultimate Earth" is a section of his novel-in-progress,Terraforming Earth . The novella has earned him his first Nebula, which he says "was well worth the wait." "The Ultimate Earth" is so packed with ideas that it's difficult to imagine what will be left for the rest of the novel. But I have faith that Jack will find something.

THE ULTIMATE EARTH.

Jack Williamson

1.

We loved Uncle Pen. The name he gave us was too hard for us to say, and we made it Sandor Pen. As early as we could understand, the robots had told us that we were clones, created to watch the skies for danger and rescue Earth from any harm. They had kept us busy with our lessons and our ch.o.r.es and our workouts in the big centrifuge, but life in our little burrow left us little else to do. His visits were our best excitement.

He never told us when he was coming. We used to watch for him, looking from the high dome on the Tycho rim, down across the field of Moondust the digging machines had leveled. Standing huge on the edge of it, they were metal monsters out of s.p.a.ce, casting long black shadows across the gray waste of rocks and dust and crater pits.

His visit on our seventh birthday was a wonderful surprise. Tanya saw him landing and called us up to the dome. His ship was a bright teardrop, shining in the black shadow of a gigantic metal insect. He jumped out of it in a sleek silvery suit that fitted like his skin. We waited inside the air lock to watch him peel it off. He was a small lean man, who looked graceful as a girl but still very strong. Even his body was exciting to see, though Dian ran and hid because he looked so strange.

Naked, his body had a light tan that darkened in the sunlit dome and faded fast when he went below. His face was a narrow heart-shape, his golden eyes enormous. Instead of hair like ours, his head was capped with sleek, red-brown fur. He needed no clothing, he told us, because his s.e.x organs were internal.

He called Dian when he missed her, and she crept back to share the gifts he had brought from Earth.

There were sweet fruits we had never tasted, strange toys, stranger games that he had to show us how to play. For Tanya and Dian there were dolls that sang strange songs in voices we couldn't understand and played loud music on tiny instruments we had never heard.The best part was just the visit with him in the dome. Pepe and Casey had eager questions about life on the new Earth. Were there cities? Wild animals? Alien creatures? Did people live in houses, or underground in tunnels like ours? What did he do for a living? Did he have a wife? Children like us?

He wouldn't tell us much. Earth, he said, had changed since our parents knew it. It was now so different that he wouldn't know where to begin, but he let us take turns looking at it through the big telescope.

Later, he promised, if he could find s.p.a.ce gear to fit us, he would take us up to orbit the Moon and loop toward it for a closer look. Now, however, he was working to learn all he could about the old Earth, the way it had been ages ago, before the great impacts.

He showed it to us in the holo tanks and the brittle old paper books, the way it was with white ice caps over the poles and bare brown deserts on the continents. Terraformed, the new Earth had no deserts and no ice. Under the bright cloud spirals, the land was green where the sun struck it, all the way over the poles. It looked so wonderful that Casey and Pepe begged him to take us back with him to let us see it for ourselves.

"I'm sorry." He shook his neat, fur-crowned head. "Terribly sorry, but you can't even think of a trip to Earth."

We were looking from the dome. Earth stood high in the black north, where it always stood. Low in the west, the slow Sun blazed hot on the new mountains the machines had piled up around the s.p.a.ceport, and filled the craters with ink.

Dian had learned by now to trust him. She sat on his knee, gazing up in adoration at his quirky face.

Tanya stood behind him, playing a little game. She held her hand against his back to bleach the golden tan, and took it away to watch the Sun erase the print.

Looking hurt, Casey asked why we couldn't think of a trip to Earth.

"You aren't like me." That was very true. Casey has a wide black face with narrow Chinese eyes and straight black hair. "And you belong right here."

"I don't look like anybody." Casey shrugged. "Or belong to you."

"Of course you don't." Uncle Pen was gently patient. "But you do belong to the station and your great mission." He looked at me. "Remind him, Dunk."

My clone father was Duncan Yarrow. The master computer that runs the station often spoke with his holo voice. He had told us how we had been cloned again and again from the tissue cells left frozen in the cryostat.

"Sir, that's true." I felt a little afraid of Uncle Pen, but proud of all the station had done. "My holo father has told us how the big impacts killed Earth and killed it again. We have always brought it back to life."

My throat felt dry. I had to gulp, but I went on. "If Earth's alive now, that's because of us."

"True. Very true." He nodded, with an odd little smile. "But perhaps you don't know that your little Moon has suffered a heavy impact of his own. If you are alive today, you owe your lives to me."

"To you?" We all stared at him, but Casey was nodding. "To you and the digging machines? I've watched them and wondered what they were digging for. When did that object hit the Moon?"

"Quien sabe?"He shrugged at Pepe, imitating the gesture and the voice Pepe had learned from his holo father. "It was long ago. Perhaps a hundred thousand years, perhaps a million. I haven't found a clue.""The object?" Pepe frowned. "Something hit the station?"

"A narrow miss." Uncle Pen nodded at the great dark pit in the crater rim just west of us. "The ejecta smashed the dome and buried everything. The station was lost and almost forgotten. Only a myth till I happened on it."

"The diggers?" Casey turned to stare down at the landing field where Uncle Pen had left his flyer in the shadows of those great machines and the mountains they had built. "How did you know where to dig?"

"The power plant was still running," Uncle Pen said. "Keeping the computer alive. I was able to detect its metal shielding and then its radiation."

"We thank you." Pepe came gravely to shake his hand. "I'm glad to be alive."

"So am I," Casey said. "If I can get to Earth." He saw Uncle Pen beginning to shake his head, and went on quickly, "Tell us what you know about the Earth impacts and how we came down to terraform the Earth and terraform it again when it was killed again."

"I don't know what you did."

"You have showed us the difference we made," Casey said. "The land is all green now, with no deserts or ice."

"Certainly it has been transformed." Nodding, Uncle Pen stopped to smile at Tanya as she left her game with the Sun on his back and came to sit cross-legged at his feet. "Whatever you did was ages ago. Our historians are convinced that we've done more ourselves."

"You changed the Earth?" Casey was disappointed and a little doubtful. "How?"

"We removed undersea ledges and widened straits to reroute the ocean circulation and warm the poles.

We diverted rivers to fill new lakes and bring rain to deserts. We engineered new life-forms that improved the whole biocosm."

"But still you owe us something. We put you there."

"Of course." Uncle Pen shrugged. "Excavating the station, I uncovered evidence that the last impact annihilated life on Earth. The planet had been reseeded sometime before the lunar impact occurred."

"We did it." Casey grinned. "You're lucky we were here."

"Your ship?" Pepe had gone to stand at the edge of the dome, looking down at the monster machines and Uncle Pen's neat little flyer, so different from the rocket s.p.a.ceplanes we had seen in the old video holos. "Can it go to other planets?"

"It can." He nodded. "The planets of other suns."

Tanya's eyes went wide, and Pepe asked, "How does it fly in s.p.a.ce with no rocket engines?"

"It doesn't," he said. "It's called a slider. It slides around s.p.a.ce, not through it."

"To the stars?" Tanya whispered. "You've been to other stars?"

"To the planets of other stars." He nodded gravely. "I hope to go again when my work here is finished.""Across the light-years?" Casey was awed. "How long does it take?"

"No time at all." He smiled at our wonderment. "Not in slider flight. Outside of s.p.a.ce-time, there is no time. But there are laws of nature, and time plays tricks that may surprise you. I could fly across a hundred light-years to another star in an instant of my own time and come back in another instant, but two hundred years would pa.s.s here on Earth while I was away."

"I didn't know." Tanya's eyes went wider still. "Your friends would all be dead."