Joan put her arm around Alyce’s waist. “Maybe so. But we have to be a broad church. We need Scott’s contribution just as much as we need yours. You know, I feel like I have a boulder in my belly,” she said breathlessly.

Alyce grimaced. “Tell me about it. I had three of them. But I went back to Iceland for them all. Ah, poor timing?”

Joan smiled. “An accident. The conference has been in the planning for two years. As for the baby—”

“Nature will take its course, as it always has, regardless of our petty concerns. The father?”

Another paleontologist, he had been caught in the middle of a meaningless brushfire war raging in the collapsed state of Kenya. He had been trying to protect hominid fossil beds from thieves; a bandit warlord had thought he was guarding silver, or diamonds, or AIDS vaccine. The experience, and the pregnancy that was its legacy, had hardened Joan’s determination to make her conference a success.

But she didn’t want to talk about it now. “A long story,” she said.

Alyce seemed to understand. She squeezed Joan’s arm.

At last they got inside the airport terminal. The coolness of the air-conditioning fell on Joan like a cold shower, though she felt a pang of guilt at the thought of the kilowatts of heat that must thereby be pumped out into the murky air somewhere else. A Qantas representative, an Aborigine woman, smoothly guided them to a reception lounge. “There’s been some trouble,” she said to the arriving passengers, over and over. “We’re in no danger. There will be an announcement shortly…”

Alyce and Joan made their way wearily to an empty metal couch. Alyce went to fetch them both some soda.

The walls of the lounge were smart, filled up with airline information, news bulletins, entertainment, phone facilities. Passengers were milling about. Many of them were conference attendees; Joan recognized their faces from the program booklet and their net sites. All obviously jet-lagged and disoriented, they looked either exhausted or hyper, or a mix of both.

A short, potbellied man in what might once have been called a Hawaiian shirt approached Joan shyly. Bald, perspiring heavily, with an apparently habitual grin on his face, he wore a button-badge that cycled images of Mars, the new NASA robot lander, an orange sky. Joan, as a small child, might have called him a nerd. But he was no older than thirty-five. A second-generation nerd, then. He held out his hand. “Ms. Useb? My name is Ian Maughan. I’m from JPL. Uh—”

“The Jet Propulsion Laboratory. NASA. I remember your name, of course.” Joan struggled to her feet and shook his hand. “I’m delighted you agreed to come. Especially at such a time in your mission.”

“It is going well, thank the great Ju-Ju,” he said. He tipped up his button-badge. “These are live images, live net of the time delay from Mars, of course. Johnnie has already set up his fuel plant and is working on metal extraction.”

“Iron, from that rusty Mars rock.”

“You got it.”

“Johnnie,” the Mars lander, was officially named for John von Neumann, the twentieth-century American thinker credited with coming up with the notion of universal replicators, machines that, given the right raw materials, could manufacture anything — including copies of themselves. “Johnnie” was a technological trial, a prototype replicator. Its ultimate goal was, in fact, to make a copy of itself from the raw materials of the planet itself.

“He’s proving an incredible hit with the public,” Maughan said with a shy smile. “People just like to watch. I think it’s the sense of purpose, of achievement as he completes one component after another.”

“Reality TV from Mars.”

“Like that, yeah. I can’t say we planned for the ratings we’re getting. Even after seventy years, NASA still doesn’t think PR very well. But the attention’s sure welcome.”

“When do you think Johnnie will have, umm, given birth? Before my own attempt at replication?”

Maughan forced a laugh, unsurprisingly embarrassed at Joan’s mention of her human biology. “Well, it’s possible. But he’s proceeding at his own pace. That’s the beauty of this project, of course. Johnnie is autonomous. Now that he’s up there, he doesn’t need anything from the ground. Since he and his sons won’t cost us another dime, this is actually a low-budget project.”

Joan thought, Sons!

“But Johnnie is more an engineering stunt than science,” said Alyce Sigurdardottir. She had returned with plastic cups of cola for herself and Joan. “Isn’t that true?”

Maughan smiled, easily enough. Joan realized belatedly that despite his appearance he must actually be one of JPL’s more PR-literate employees; otherwise he wouldn’t be here. “I can’t deny that,” he said. “But that’s our way. At NASA, the engineering and the science have always had to proceed hand in hand.” He turned back to Joan. “I’m honored you asked me here, though I’m still not sure why. My grasp of biology is kind of flaky. I’m basically a computer scientist. And Johnnie is just another space probe, a hunk of silicon and aluminum.”

Joan said, “This conference isn’t just about biology. I wanted the best and brightest minds in many fields to come here and get in touch with each other. We’ve got to learn to think in a new way.”

Alyce shook her head. “And for all my skepticism about this specific project, I think you underestimate yourself, Dr. Maughan. Think about it. You come into the world naked. You take what the Earth gives you — metal, oil — and you mold it, make it smart, and hurl it across space to another world. NASA’s image has always been dismally poor. But what you actually do is so — romantic.”

Maughan hid behind a weak joke. “Gee, ma’am, I’ll have to invite you along to my next career review.”

The lounge was continuing to fill up with passengers. Joan said, “Does anybody know what’s happening?”

“It’s the protesters,” Ian Maughan said. “They are lobbing rocks into the airport compound. The police are pushing them back, but it’s a mess. They let us land, but it’s not safe for our baggage to be retrieved right now, or for us to leave the airport.”

“Terrific,” Joan said. “So we’re going to be under siege all through the conference.”

Alyce asked, “Who’s involved?”

“Mostly the Fourth World.” An umbrella group, based on a splinter Christian sect, that claimed to represent the interests of the global underclass: the so-called Fourth World, people with less visibility even than the nations and groupings that made up the Third World — the poorest and most excluded, beneath the radar of the rich northern and western nations. “They think Pickersgill himself is in Australia.”

Joan felt a flickering of unease. British-born Gregory Pickersgill was the charismatic leader of the central cult; the worst kind of trouble — sometimes lethal — followed him around. Deliberately she put the worry aside. “Let’s leave it to the police. We have a conference to run.”

“And a planet to save,” said Ian Maughan, smiling.

“Damn right.”

In one corner of the terminal, there was a commotion as a large white box was wheeled in. It was like an immense refrigerator. Light flared, and cameras were thrust into Alison Scott’s face.

“One piece of luggage that evidently couldn’t wait,” murmured Alyce.

“I think it’s live cargo,” Maughan said. “I heard them talking about it.”

Now little Bex Scott came running up to Joan. Joan noticed Ian Maughan goggling at her blue hair and red eyes; maybe folk were a little backward in Pasadena. “Oh, Dr. Useb.” Bex took Joan’s hand. “I want you to see what my mother has brought. You, too, Dr. Sigurdardottir. Please come. Uh, you were kind to me on the plane. I really was frightened by all the smoke and the lurching.”

“You weren’t in any real danger.”

“I know. But I was frightened even so. You saw that and you were kind. Come on, I’d love you to see.”