Clavain shrugged. “I don’t know. Five hundred? A thousand? ”
“No. Six. Not six hundred, just six. Six damned neurons. You can’t get much simpler than that. But it took decades to understand how those six worked together, let alone how that particular network evolved. The problems aren’t inseparable, either. You can’t really hope to understand how ten billion neurons organise themselves into a functioning whole unless you understand how the whole actually functions. Oh, we’ve made some progress—we can tell you exactly which spinal neurons fire to make a lamprey swim, and how that firing pattern maps into muscle motion—but we’re a long way from understanding how something as elusive as the concept of ‘I’ emerges in the developing human mind. Well, at least we were before I went under. You may be about to reveal that you’ve achieved stunning progress in the last century, but something tells me you were too busy with social upheaval for that.”
Clavain felt an urge to argue—angered by the man’s tone—but suppressed it, willing himself into a state of serene acceptance. “You’re probably right. We’ve made progress in the other direction—augmenting the mind as it is—but if we genuinely understood brain development, we wouldn’t have ended up with a failure like Felka.”
“Oh, I wouldn’t call her a failure, Nevil.”
“I didn’t mean it like that.”
“Of course not.” Now it was Iverson’s turn to place a hand on Clavain’s shoulder. “But you must see now why I find Felka so fascinating. Her mind is damaged—you told me that yourself, and there’s no need to go into the details—but despite that damage, despite the vast abysses in her head, she’s beginning to self-assemble the kinds of higher-level neural routines we all take for granted. It’s as if the patterns were always there as latent potentials, and it’s only now that they’re beginning to emerge. Isn’t that fascinating? Isn’t it something worthy of study?”
Delicately, Clavain removed the man’s hand from his shoulder. “I suppose so. I had hoped, however, that there might be something more to it than study.”
“I’ve offended you, and I apologise. My choice of phrase was poor. Of course I care for her.”
Clavain felt suddenly awkward, as if he had misjudged a fundamentally decent man. “I understand. Look, ignore what I said.”
“Yeah, of course. It—um—will be all right for me to see her again, won’t it?”
Clavain nodded. “I’m sure she’d miss you if you weren’t around.”
Over the next few days, Clavain left the two of them to their games, only rarely eavesdropping to see how things were going. Iverson had asked permission to show Felka around some of the other areas of the base, and after a few initial misgivings Clavain and Galiana had both agreed to his request. After that, long hours went by when the two of them were not to be found. Clavain had tracked them once, watching as Iverson led the girl into a disused lab and showed her intricate molecular models. They clearly delighted her; vast fuzzy holographic assemblages of atoms and chemical bonds that floated in the air like Chinese dragons. Wearing cumbersome gloves and goggles, Iverson and Felka were able to manipulate the mega-molecules, forcing them to fold into minimum-energy configurations that brute-force computation would have struggled to predict. As they gestured into the air and made the dragons contort and twist, Clavain watched for the inevitable moment when Felka would grow bored and demand something more challenging. But it never came. Afterwards—when she had returned to the fold, her face shining with wonder—it was as if Felka had undergone a spiritual experience. Iverson had shown her something her mind could not instantly encompass; a problem too large and subtle to be stormed in a flash of intuitive insight.
Seeing that, Clavain again felt guilty about the way he had spoken to Iverson, and knew that he had not completely put aside his doubts about the message Setterholm had left in the ice. But—the riddle of the helmet aside— there was no reason to think that Iverson might be a murderer beyond those haphazard marks. Clavain had looked into Iverson’s personnel records from the time before he was frozen, and the man’s history was flawless. He had been a solid, professional member of the expedition, well liked and trusted by the others. Granted, the records were patchy, and since they were stored digitally they could have been doctored to almost any extent. But then much the same story was told by the hand-written diary and verbal log entries of some of the other victims. Andrew Iverson’s name came up again and again as a man regarded with affection by his fellows; most certainly not someone capable of murder. Best, then, to discard the evidence of the marks and give him the benefit of the doubt.
Clavain spoke of his fears to Galiana, and while she listened to him, she only came back with exactly the same rational counterarguments he had already provided for himself.
“The problem is,” Galiana said, “that the man you found in the crevasse could have been severely confused, perhaps even hallucinatory. That message he left—if it was a message, and not just a set of random gouge marks he made while convulsing—could mean anything at all.”
“We don’t know that Setterholm was confused,” Clavain protested.
“We don’t? Then why didn’t he make sure his helmet was on properly? It can’t have been latched fully, or it wouldn’t have rolled off him when he hit the bottom of the crevasse.”
“Yes,” Clavain said. “But I’m reasonably sure he wouldn’t have been able to leave the base if his helmet hadn’t been latched.”
“In which case he must have undone it afterwards.”
“Yes, but there’s no reason for him to have done that, unless . . .”
Galiana gave him a thin-lipped smile. “Unless he was confused. Back to square one, Nevil.”
“No,” he said, conscious that he could almost see the shape of something; something that was close to the truth if not the truth itself. “There’s another possibility, one I hadn’t thought of until now.”
Galiana squinted at him, that rare frown appearing. “Which is?”
“That someone else removed his helmet for him.”
They went down into the bowels of the base. In the dead space of the equipment bays Galiana became ill at ease. She was not used to being out of communicational range of her colleagues. Normally systems buried in the environment picked up neural signals from individuals, amplifying and rebroadcasting them to other people, but there were no such systems here. Clavain could hear Galiana’s thoughts, but they came in weakly, like a voice from the sea almost drowned by the roar of surf.
“This had better be worth it,” Galiana said.
“I want to show you the airlock,” Clavain answered. “I’m sure Setterholm must have left here with his helmet properly attached.”
“You still think he was murdered?”
“I think it’s a remote possibility that we should be very careful not to discount.”
“But why would anyone kill a man whose only interest was a lot of harmless ice-worms?”
“That’s been bothering me as well.”
“And?”
“I think I have an answer. Half of one, anyway. What if his interest in the worms brought him into conflict with the others? I’m thinking about the reactor.”
Galiana nodded. “They’d have needed to harvest ice for it.”
“Which Setterholm might have seen as interfering with the worms’ ecology. Maybe he made a nuisance of himself and someone decided to get rid of him.”
“That would be a pretty extreme way of dealing with him.”
“I know,” Clavain said, stepping through a connecting door into the transport bay. “I said I had half an answer, not all of one.”
As soon as he was through he knew something was amiss. The bay was not as it had been before, when he had come down here scouting for clues. He dropped his train of thought immediately, focusing only on the now.
The room was much, much colder than it should have been. And brighter. There was an oblong of chill blue daylight spilling across the floor from the huge open door of one of the vehicle exit ramps. Clavain looked at it in mute disbelief, wanting it to be a temporary glitch in his vision. But Galiana was with him, and she had seen it, too.
“Someone’s left the base,” she said.
Clavain looked out across the ice. He could see the wake the vehicle had left in the snow, arcing out towards the horizon. For a long moment they stood at the top of the ramp, frozen into inaction. Clavain’s mind screamed with the implications. He had never really liked the idea of Iverson taking Felka away with him elsewhere in the base, but he had never considered the possibility that he might take her into one of the blind zones. From here, Iverson must have known enough little tricks to open a surface door, start a rover and leave, without any of the Conjoiners realising.
“Nevil, listen to me,” Galiana said. “He doesn’t necessarily mean her any harm. He might just want to show her something.”
He turned to her. “There isn’t time to arrange a shuttle. That party trick of yours—talking to the door? Do you think you can manage it again?”
“I don’t need to. The door’s already open.”
Clavain nodded at one of the other rovers, hulking behind them. “It’s not the door I’m thinking about.”
Galiana was disappointed: it took her three minutes to convince the machine to start, rather than the few dozen seconds she said it should have taken. She was, she told Clavain, in serious danger of getting rusty at that sort of thing. Clavain just thanked the gods that there had been no mechanical sabotage to the rover; no amount of neural intervention could have fixed that.
“That’s another thing that makes it look as if this is just an innocent trip outside,” Galiana said. “If he’d really wanted to abduct her, it wouldn’t have taken much additional effort to stop us following him. If he’d closed the door, as well, we might not even have noticed he was gone.”
“Haven’t you ever heard of reverse psychology?” Clavain said.
“I still can’t see Iverson as a murderer, Nevil.” She checked his expression, her own face calm despite the effort of driving the machine. Her hands were folded in her lap. She was less isolated now, having used the rover’s comm systems to establish a link back to the other Conjoiners. “Setterholm, maybe. The obsessive loner and all that. Just a shame he’s the dead one.”
“Yes,” Clavain said, uneasily.
The rover itself ran on six wheels, a squat, pressurised hull perched low between absurd-looking balloon tyres. Galiana gunned them hard down the ramp and across the ice, trusting the machine to glide harmlessly over the smaller crevasses. It seemed reckless, but if they followed the trail Iverson had left, they were almost guaranteed not to hit any fatal obstacles.
“Did you get anywhere with the source of the sickness? ” Clavain asked.
“No breakthroughs yet—”
“Then here’s a suggestion. Can you read my visual memory accurately?” Clavain did not need an answer. “While you were finding Iverson’s body, I was looking over the lab samples. There were a lot of terrestrial organisms there. Could one of those have been responsible?”
“You’d better replay the memory.”
Clavain did so: picturing himself looking over the rows of culture dishes, test tubes and gel slides; concentrating especially on those that had come from Earth rather than the locally obtained samples. In his mind’s eye the sample names refused to snap into clarity, but the machines Galiana had seeded through his head would already be locating the eidetically stored short-term memories and retrieving them with a clarity beyond the capabilities of Clavain’s own brain.
“Now see if there’s anything there that might do the job.”
“A terrestrial organism?” Galiana sounded surprised. “Well, there might be something there, but I can’t see how it could have spread beyond the laboratory unless someone wanted it to.”
“I think that’s exactly what happened.”
“Sabotage?”
“Yes.”
“Well, we’ll know sooner or later. I’ve passed the information to the others. They’ll get back to me if they find a candidate. But I still don’t see why anyone would sabotage the entire base, even if it was possible. Overthrowing the von Neumann machines is one thing . . . mass suicide is another.”
“I don’t think it was mass suicide. Mass murder, maybe.”
“And Iverson’s your main suspect?”
“He survived, didn’t he? And Setterholm scrawled a message in the ice just before he died. It must have been a warning about him.” But even as he spoke, he knew there was a second possibility; one that he could not quite focus on.
Galiana swerved the rover to avoid a particularly deep and yawning chasm, shaded with vivid veins of turquoise blue.
“There’s a small matter of missing motive.”
Clavain looked ahead, wondering if the thing he saw glinting in the distance was a trick of the eye. “I’m working on that,” he said.
Galiana halted them next to the other rover. The two machines were parked at the lip of a slope-sided depression in the ice. It was not really steep enough to call a crevasse, although it was at least thirty or forty metres deep. From the rover’s cab it was not possible to see all the way into the powdery blue depths, although Clavain could certainly make out the fresh footprints descending into them. Up on the surface, marks like that would have been scoured away by the wind in days or hours, so these prints were very fresh. There were, he observed, two sets—someone heavy and confident and someone lighter, less sure of their footing.
Before they had taken the rover they had made sure there were two suits aboard it. They struggled into them, fiddling with the latches.
“If I’m right,” Clavain said, “this kind of precaution isn’t really necessary. Not for avoiding the sickness, anyway. But better safe than sorry.”
“Excellent timing,” Galiana said, snapping down her helmet and giving it a quarter twist to lock into place. “They’ve just pulled something from your memory, Nevil. There’s a family of single-celled organisms called dinoflagellates, one of which was present in the lab where we found Iverson. Something called
Pfiesteria piscicida.
Normally it’s an ambush predator that attacks fish.”