She said, “We’re having trouble holding off the Terrans, Nirgal. They’re sending up almost a million a year, just like you said they never could. And these new arrivals aren’t joining Free Mars like they used to. They’re still supporting their home governments. Mars isn’t changing them fast enough. If this goes on, then the whole idea of a free Mars will be a joke. I sometimes wonder if it was a mistake to leave the cable up.”
She frowned and twenty years jumped onto her face all at once. Nirgal suppressed a little shudder.
“It would help if you weren’t hiding here,” she exclaimed with sudden anger, dismissing the basin with a wave of her hand. “We need everyone we can get to help. People still remember you now, but in a few years…”
So he only had to wait a few more years, he thought. He watched her. She was beautiful, yes. But beauty was a matter of the spirit, of intelligence, vivacity, empathy. So that while Jackie grew ever more beautiful, at the same time she grew less beautiful. Another mysterious infolding. And Nirgal was not pleased by this internal loss in Jackie, not in any way; it was only one more note in the chord of his Jackie pain, really. He didn’t want it to be true.
“We can’t really help them by taking more immigrants,” she said. “That was wrong, when you said that on Earth. They know it too. They can see it better than we can, no doubt. But they send people anyway. And you know why? You know why? Just to wreck things here. Just to make sure there isn’t someplace where people are doing it right. That’s their only reason.”
Nirgal shrugged. He didn’t know what to say; probably there was some truth to what she had said, but it was just one of a million different reasons for people to come; there was no reason to fix on it.
“So you won’t come back,” she said at last. “You don’t care.”
Nirgal shook his head. How to say to her that she was not worried about Mars, but about her own power? He wasn’t the one who could tell her that. She wouldn’t believe him. And maybe it was only true to him anyway.
Abruptly she stopped trying to reach him. A regal glance at Antar, and Antar did the work of gathering their coterie into the cars. A final questioning look; a kiss, full on the mouth, no doubt to bother Antar, or him, or both of them; like an electric shock to the soul; and she was off.
He spent the afternoon and the next day wandering, sitting on flat rocks and watching the little rivulets bounce downstream. Once he remembered how fast water had fallen on Earth. Unnatural. No. But this was his place, known and loved, every dyad and every clump of campion, even the speed of water as it lofted off stone and plashed down in its smooth silver shapes. The way moss felt under the finger pads. His visitors were people for whom Mars was forever an idea, a nascent state, a political situation. They lived in the tents and they might as well have been in a city anywhere, and their devotion, while real, was given to some cause or idea, some Mars of the mind. Which was fine. But for Nirgal now it was the land that mattered, the places where water arrived just so, trickling over the billion-year-old rock onto pads of new moss. Leave politics to the young, he had done his part. He didn’t want to do anymore. Or at least he wanted to wait until Jackie was gone. Power was like Hiroko, after all — it always slipped away. Didn’t it? Meanwhile, the cirque like an open hand.
But then one morning when he went out for a dawn walk, there was something different. The sky was clear, its purest morning purple, but a juniper’s needles had a yellowish tinge to them, and so did the moss, and the potato leaves on their mounds.
He plucked the yellowest samples of needles and sprigs and leaves, and took them back to the workbench in his greenhouse. Two hours’ work with microscope and AI did not find any problem, and he went back out and pulled up some root samples, and bagged some more needles and leaves and blades and flowers. Much of the grass had a wilted look, though it wasn’t a hot day.
Heart thudding, stomach taut, he worked all day and into the night. He could discover nothing. No insects, no pathogens. But the potato leaves in particular looked yellow. That night he called Sax and explained the situation. By coincidence Sax was visiting the university in Sabishii, and he drove up the next morning in a little rover, the latest from Spencer’s co-op.
“Nice,” Sax said as he got out and looked around. He checked Nirgal’s samples in the greenhouse. “Hmm,” he said. “I wonder.”
He had brought some instruments in his car, and they lugged them into the boulder and he went to work. At the end of a long day he said, “I can’t find anything. We’ll have to take some samples down to Sabishii.”
“You can’t find anything?”
“No pathogen. No bacteria, no virus.” He shrugged. “Let’s take several potatoes.”
They went out and dug potatoes from the field. Some of them were gnarled, elongated, cracked. “What is it?” Nirgal exclaimed.
Sax was frowning a little. “Looks like spindle tuber disease.”
“What causes it?”
“A viroid.”
“What’s that?”
“A bare RNA fragment. Smallest known infectious agent. Strange.”
“Ka.” Nirgal felt his stomach clamping inward. “How did it get here?”
“On a parasite, probably. This kind seems to be infecting grass. We need to find out.”
So they gathered samples, and drove back down to Sabishii.
Nirgal sat on a futon on the floor of Tariki’s living room, feeling sick. Tariki and Sax talked long after dinner, discussing the situation. Other viroids had been appearing in a rapid dispersal from Tharsis; apparently they had made it across the cordon sanitaire of space, arriving on a world that had been previously innocent of them. They were smaller than viruses, much smaller, and quite a bit simpler. Nothing but strands of RNA, Tariki said, about fifty nanometers long. Individuals had a molecular weight of about 130,000, while the smallest known viruses had molecular weights of over a million. They were so small that they had to be centrifuged at over 100,000 g in order to be pulled out of suspension.
The potato-spindle-tuber viroid was well understood, Tariki told them, tapping around on his screen and pointing at the schematics called up. A chain of merely 359 nucleo-tides, lined out in a closed single strand with short double-strand regions braiding it. Viroids like this one caused several plant diseases, including pale cucumber disease, chrysanthemum stunt, chlorotic mottle, cadang-cadang, citrus exocortis. Viroids had also been confirmed as the agent in some animal brain diseases, like scrapie, and kuru, and Creutzfeldt-Jakob disease in humans. The viroids used host enzymes to reproduce, and then were taken to be-regulatory molecules in the nuclei of infected cells, disturbing growth-hormone production in particular.
The particular viroid in Nirgal’s basin, Tariki said, had mutated from potato spindle tuber. They were still identifying it in the labs at the university, but the sick grass made him sure they were going to find something different, something new.
Nirgal felt sick. The names of the diseases alone were enough to do it. He stared at his hands, which had been plunged thick in infected plants. Through the skin, into the brain, some kind of spongiform encephalopathy, mushroom growths of brain blooming everywhere.
“Is there anything we can do to fight it?” he said.
Sax and Tariki looked at him.
“First,” Sax said, “we have to find out what it is.”
That turned out to be no simple matter. After a few days, Nirgal returned to his basin. There he could at least do something; Sax had suggested removing all the potatoes from the potato fields. This was a long dirty task, a kind of negative treasure hunt, as he turned up diseased tuber after tuber. Presumably the soil itself would still hold the viroid. It was possible he would have to abandon the field, or even the basin. At best, plant something else. No one yet understood how viroids reproduced; and the word from Sabishii was that this might not even be a viroid as previously understood.