formations blurred past, and then long stretches of sulfur-eating pavement. The proxy caromed off the narrowing walls and began to tumble madly.
Margaret had no control. She was a helpless but exhilarated passenger. She passed the place where she had set the relay and continued to fall. The link started to breakup. She lost all sense of proprioception, although given the tumbling fall of the proxy that was a blessing. Then the microwave radar started to go, with swathes of raster washing across the false color view. Somehow the proxy managed to stabilize itself, so it was falling headfirst toward the unknown regions at the bottom of the Rift. Margaret glimpsed structures swelling from the walls. And then everything went away and she was back, sweating and nauseous in the couch.
It was bad. More than ninety-five percent of the proxies had been lost. Most, like Margaret’s had been lost in the depths. A few, badly damaged by collision, had been stranded among the reef colonies, but proxies sent to retrieve them went out of control too. It was clear that some kind of infective process had affected them. Margaret had several dead proxies collected by a maintenance robot and ordered that the survivors should be regrouped and kept above the deep part of the Rift where the vacuum organisms proliferated. And then she went to her suite in the undercroft and waited for the Star Chamber to call her before them.
The Star Chamber took away Margaret’s contract, citing failure to perform and possible sedition (that remarkin the seminar had been recorded). She was moved from her suite to a utility room in the lower level of the undercroft and put to workin the farms.
She thought of her parents.
She had been here before.
She thought of the reef.
She couldn’t let it go.
She would save it if she could.
Srin Kerenyi kept her up to date. The survey crew and its proxies were restricted to the upper level of the reef. Manned teams under Opie Kindred’s control were exploring the depths-hewas trusted where Margaret was not-but if they discovered anything it wasn’t communicated to the other science crews.
Margaret was working in the melon fields when Arn Nivedta found her. The plants sprawled from hydroponic tubes laid across gravel beds, beneath blazing lamps hung in the axis of the farmlands. It was very hot, and there was a stink of dilute sewage. Little yellow ants swarmed everywhere. Margaret had tucked the ends of her pants into the rolled tops of her shoesocks, and wore a green eyeshade. She was using a fine paintbrush to transfer pollen to the stigma of the melon flowers.
Arn came bouncing along between the long rows of plants like a pale scarecrow intent on escape. He wore only tight blackshorts and a web belt hung with pens, little silvery tools and a notepad.
He said, “They must hate you, putting you in a shithole like this.”
“I have to work, Arn. Work or starve. I don’t mind it. I grew up working the fields.”
Not strictly true: her parents had been ecosystem designers. But it was how it had ended.
Arn said cheerfully, “I’m here to rescue you. I can prove it wasn’t your fault.”
Margaret straightened, one hand on the small of her back where a permanent ache had lodged itself. She said, “Of course it wasn’t my fault. Are you all right?”
Arn had started to hop about, brushing at one bare long-toed foot and then the other. The ants had found him. His toes curled like fingers. The big toes were opposed. Monkey feet.
“Ants are having something of a population explosion,” she said. “We’re in the stage between introduction and stabilization here. The cycles will smooth out as the ecosystem matures.”
Arn brushed at his legs again. His prehensile big toe flicked an ant from the sole of his foot. “They want to incorporate me into the cycle, I think.”
“We’re all in the cycle, Arn. The plants grow in sewage; we eat the plants.” Margaret saw her supervisor coming toward them through the next field. She said, “We can’t talk here. Meet me in my room after work.”
Margaret’s new room was barely big enough for a hammock, a locker, and a tiny shower with a toilet pedestal. Its rockwalls were unevenly coated with dull green fiber spray. There was a constant noise of pedestrians beyond the oval hatch; the air conditioning allowed in a smell of frying oil and ketones despite the filter trap Margaret had set up. She had stuckan aerial photograph of New York, where she had been born, above the head stay of her hammock, and dozens of glossy printouts of the reef scaled the walls. Apart from the pictures, a few clothes in the closet and the spider plant under the purple grolite, the room was quite anonymous.
She had spent most of her life in rooms like this. She could pack in five minutes, ready to move onto the next job.
“This place is probably bugged,” Arn said. He sat with his back to the door, sipping schnapps from a silvery flask and looking at the overlapping panoramas of the reef.
Margaret sat on the edge of her hammock. She was nervous and excited. She said, “Everywhere is bugged. I want them to hear that I’m not guilty. Tell me what you know.”
Arn looked at her. “I examined the proxies you sent back. I wasn’t quite sure what I was looking for, but it was surprisingly easy to spot.”
“An infection,” Margaret said.
“Yah, a very specific infection. We concentrated on the nervous system, given the etiology. In the brain we found lesions, always in the same area.”
Margaret examined the three-dimensional color-enhanced tomographic scan Arn had brought. The lesions were little blackbubbles in the underside of the unfolded cerebellum, just in front of the optic node.
“The same in all of them,” Arn said. “We took samples, extracted DNA, and sequenced it.” A grid of thousands of colored dots, then another superimposed over it. All the dots lined up.
“A match to Opie’s parasite,” Margaret guessed.
Arn grinned. He had a nice smile. It made him look like an enthusiastic boy. “We tried that first of course.
Got a match, then went through the library of reef organisms, and got partial matches. Opie’s parasite has its fingerprints in the DNA of everything in the reef, but this-” he jabbed a long finger through the projection-“is the pure quill. Just an unlucky accident that it lodges in the brain at this particular place and produces the behavior you saw.”
“Perhaps it isn’t a random change,” Margaret said. “Perhaps the reef has a use for the proxies.”
“Teleology,” Arn said. “Don’t let Opie hear that thought. He’d use it against you. This is evolution. It isn’t directed by anything other than natural selection. There is no designer, no watchmaker. Not after the AI crashed, anyway, and it only pushed the ecosystem toward more efficient sulfur oxidation. There’s more, Margaret. I’ve been doing some experiments on the side. Exposing aluminum foil sheets in orbit around Enki. There are exfoliations everywhere.”
“Then Opie is right.”
“No, no. All the exfoliations I found were nonviable. I did more experiments. The exfoliations are metabolically active when released, unlike bacterial spores. And they have no protective wall. No reason for them to have one, yah? They live only for a few minutes. Either they land on a new host or they don’t.
Solar radiation easily tears them apart. You can kill them with a picowatt ultraviolet laser. Contamination isn’t a problem.”
“And it can’t infect us,” Margaret said. “Vacuum organisms and proxies have the same DNA code as us, the same as everything from Earth, for that matter, but it’s written in artificial nucleotide bases. The reef isn’t dangerous at all, Arn.”
“Yah, but in theory it could infect every vacuum organism ever designed. The only way around it would be to change the base structure of vacuum organism DNA-how much would that cost?”
“I know about contamination, Arn. The mold that wrecked the biome designed by my parents came in with someone or something. Maybe on clothing, or skin, or in the gut, or in some trade goods. It grew on anything with a cellulose cell wall. Every plant was infected. The fields were covered by huge sheets of gray mold; the air was full of spores. It didn’t infect people, but more than a hundred died from massive allergic reactions and respiratory failure. They had to vent the atmosphere in the end. And my parents couldn’t find work after that.”
Arn said gently, “That is the way. We live by our reputations. It’s hard when something goes wrong.”
Margaret ignored this. She said, “The reef is a resource, not a danger. You’re looking at it the wrong way, like Opie Kindred. We need diversity. Our biospheres have to be complicated because simple systems are prone to invasion and disruption, but they aren’t one hundredth as complicated as those on Earth. If my parents’ biome had
