‘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.’
‘Could it have been responsible for the madness?’
‘It’s at least a strong contender. It has a taste for mammalian tissue as well. If it gets into the human nervous system it produces memory loss, disorientation - as well as a host of physical effects. It could have been dispersed as a toxic aerosol, released into the base’s air system. Someone with access to the lab’s facilities could have turned it from something merely nasty into something deadly, I think.’
‘We should have pinpointed it, Galiana. Didn’t we swab the air ducts?’
‘Yes, but we weren’t looking for something terrestrial. In fact we were excluding terrestrial organisms, only filtering for the basic biochemical building blocks of Diadem life. We just weren’t thinking in criminal terms.’
‘More fool us,’ Clavain said.
Suited now, they stepped outside. Clavain began to regret his haste in leaving the base so quickly; at having to make do with these old suits and lacking any means of defence. Wanting something in his hand for moral support, he examined the equipment stowed around the outside of the rover until he found an ice pick. It would not be much of a weapon, but he felt better for it.
‘You won’t need that,’ Galiana said.
‘What if Iverson turns nasty?’
‘You still won’t need it.’
But he kept hold of it anyway - an ice pick was an ice pick, after all - and the two of them walked to the point where the icy ground began to curve over the lip of the depression. Clavain examined the wrist of his suit, studying the cryptic and old-fashioned matrix of keypads that controlled the suit’s functions. On a whim he pressed something promising and was gratified when he felt crampons spike from the soles of his boots, anchoring him to the ice.
‘Iverson!’ he shouted. ‘Felka!’
But sound carried poorly beyond his helmet, and the ceaseless, whipping wind would have snatched his words away from the crevasse. There was nothing for it but to make the difficult trek into the blue depths. He led the way, his heart pounding in his chest, the old suit awkward and top-heavy. He almost lost his footing once or twice, and had to stop to catch his breath when he reached the level bottom of the depression, sweat running into his eyes.
He looked around. The footprints led horizontally for ten or fifteen metres, weaving between fragile, curtain-like formations of opal ice. On some clinical level he acknowledged that the place had a sinister charm - he imagined the wind breathing through those curtains of ice, making ethereal music - but the need to find Felka eclipsed such considerations. He focused only on the low, dark-blue hole of a tunnel in the ice ahead of them. The footprints vanished into the tunnel.
‘If the bastard’s taken her . . .’ Clavain said, tightening his grip on the pick. He switched on his helmet light and stooped into the tunnel, Galiana behind him. It was hard going; the tunnel wriggled, rose and descended for many tens of metres, and Clavain was unable to decide whether it was some weird natural feature - carved, perhaps, by a hot sub-glacial river - or whether it had been dug by hand, much more recently. The walls were veined with worm tracks: a marbling like an immense magnification of the human retina. Here and there Clavain saw the dark smudges of worms moving through cracks that were very close to the surface, though he knew it would be necessary to stare at them for long seconds before any movement was discernible. He groaned, the stooping becoming painful, and then the tunnel widened out dramatically. He realised that he had emerged into a much larger space.
It was still underground, although the ceiling glowed with the blue translucence of filtered daylight. The covering of ice could not have been more than a metre or two thick; a thin shell stretched like a dome over tens of metres of yawing nothing. Nearly sheer walls of delicately patterned ice rose up from a level, footprint-dappled floor.
‘Ah,’ said Iverson, who was standing near one wall of the chamber. ‘You decided to join us.’
Clavain felt a stab of relief seeing that Felka was standing not far from him, next to a piece of equipment Clavain failed to recognise. Felka appeared unharmed. She turned towards him, the peculiar play of light and shade on her helmeted face making her look older than she was.
‘Nevil,’ he heard Felka say. ‘Hello.’
He crossed the ice, fearful that the whole marvellous edifice was about to come crashing down on them all.
‘Why did you bring her here, Iverson?’
‘There’s something I wanted to show her. Something I knew she’d like, even more than the other things.’ He turned to the smaller figure near him. ‘Isn’t that right, Felka?’
‘Yes.’
‘And do you like it?’
Her answer was matter of fact, but it was closer to conversation than anything Clavain had ever heard from her lips.
‘Yes. I do like it.’
Galiana stepped ahead of him and extended a hand to the girl. ‘Felka? I’m glad you like this place. I like it, too. But now it’s time to come back home.’
Clavain steeled himself for an argument, some kind of show-down between the two women, but to his immense relief Felka walked casually towards Galiana.
‘I’ll take her back to the rover,’ Galiana said. ‘I want to make sure she hasn’t had any problems breathing with that old suit on.’
A transparent lie, but it would suffice.
Then she spoke to Clavain. It was a tiny thing, almost inconsequential, but she placed it directly in his head.
And he understood what he would have to do.
When they were alone, Clavain said, ‘You killed him.’
‘Setterholm?’
‘No. You couldn’t have killed Setterholm because
you are Setterholm. ’ Clavain looked up, the arc of his helmet light tracing the filamentary patterning until it became too tiny to resolve; blurring into an indistinct haze of detail that curved over into the ceiling itself. It was like admiring a staggeringly ornate fresco.
‘Nevil - do me a favour? Check the settings on your suit, in case you’re not getting enough oxygen.’
‘There’s nothing wrong with my suit.’ Clavain smiled, the irony of it all delicious. ‘In fact, it was the suit that tipped me off. When you pushed Iverson into the crevasse, his helmet came off. That couldn’t have happened unless it wasn’t fixed on properly in the first place - and that couldn’t have happened unless someone had removed it after the two of you left the base.’
Setterholm - he was sure the man was Setterholm - snorted derisively, but Clavain continued speaking.
‘Here’s my stab at what happened, for what it’s worth. You needed to swap identities with Iverson because Iverson had no obvious motive for murdering the others, whereas Setterholm certainly did.’
‘And I don’t suppose you have any idea what that motive might have been?’
‘Give me time; I’ll get there eventually. Let’s just deal with the lone murder first. Changing the electronic records was easy enough - you could even swap Iverson’s picture and medical data for your own - but that was only part of it. You also needed to get Iverson into your clothes and suit, so that we’d assume the body in the crevasse belonged to you, Setterholm. I don’t know exactly how you did it.’
‘Then perhaps—’
Clavain carried on. ‘But my guess is you let him catch a dose of the bug you let loose in the main base - Pfiesteria, wasn’t it? - then followed him when he went walking outside. You jumped him, knocked him down on the ice and got him out of his suit and into yours. He was probably unconscious by then, I suppose. But then he must have started coming round, or you panicked for another reason. You jammed the helmet on and pushed him into the crevasse. Maybe if all that had happened was his helmet coming off, I wouldn’t have dwelled on it. But he wasn’t dead, and he lived long enough to scratch a message in the ice. I thought it concerned his murderer, but I was wrong. He was trying to tell me who he was. Not Setterholm, but Iverson.’
‘Nice theory.’ Setterholm glanced down at a display screen in the back of the machine squatting next to him. Mounted on a tripod, it resembled a huge pair of binoculars, pointed with a slight elevation towards one wall of the chamber.
‘Sometimes a theory’s all you need. That’s quite a toy you’ve got there, by the way. What is it, some kind of ground-penetrating radar?’
Setterholm brushed aside the question. ‘If I was him - why would I have done it? Just because I was interested in the ice-worms? ’
‘It’s simple,’ Clavain said, hoping the uncertainty he felt was not apparent in his voice. ‘The others weren’t as convinced as you were of the worms’ significance. Only you saw them for what they were.’ He was treading carefully here; masking his ignorance of Setterholm’s deeper motives by playing on the man’s vanity.
‘Clever of me if I did.’
‘Oh, yes. I wouldn’t doubt that at all. And it must have driven you to distraction, that you could see what the others couldn’t. Naturally, you wanted to protect the worms, when you saw them under threat.’
‘Sorry, Nevil, but you’re going to have to try a lot harder than that.’ He paused and patted the machine’s matt-silver casing, clearly unable to pretend that he did not know what it was. ‘It’s radar, yes. It can probe the interior of the glacier with sub-centimetre resolution, to a depth of several tens of metres.’
‘Which would be rather useful if you wanted to study the worms.’
Setterholm shrugged. ‘I suppose so. A climatologist interested in glacial flow might also have use for the information.’
‘Like Iverson?’ Clavain took a step closer to Setterholm and the radar equipment. He could see the display more clearly now: a fibrous tangle of mainly green lines slowly spinning in space, with a denser structure traced out in red near its heart. ‘Like the man you killed?’
‘I told you, I’m Iverson.’
Clavain stepped towards him with the ice pick held double-handed, but when he was a few metres from the man he veered past and made his way to the wall. Setterholm had flinched, but he had not seemed unduly worried that Clavain was about to try to hurt him.
‘I’ll be frank with you,’ Clavain said, raising the pick. ‘I don’t really understand what it is about the worms.’
‘What are you going to do?’
‘This.’
Clavain smashed the pick against the wall as hard as he was able. It was enough: a layer of ice fractured noisily away, sliding down like a miniature avalanche to land in pieces at his feet; each fist-sized shard was veined with worm trails.
‘Stop,’ Setterholm said.
‘Why? What do you care, if you’re not interested in the worms?’
Clavain smashed the ice again, dislodging another layer.
‘You . . .’ Setterholm paused. ‘You could bring the whole place down on us if you’re not careful.’
Clavain raised the pick again, letting out a groan of effort as he swung. This time he put all his weight behind the swing, all his fury, and a chunk the size of his upper body calved noisily from the wall.
‘I’ll take that risk,’ Clavain said.
‘No. You’ve got to stop.’
‘Why? It’s only ice.’
‘No!’
Setterholm rushed him, knocking him off his feet. The ice pick spun from his hand and the two of them crashed into the ground, Setterholm landing on his chest. He pressed his faceplate close to Clavain’s, every bead of sweat on his forehead gleaming like a precise little jewel.
‘I told you to stop.’
Clavain found it difficult to speak with the pressure on his chest, but forced out the words with effort. ‘I think we can dispense with the charade that you’re Iverson now, can’t we?’
‘You shouldn’t have harmed it.’
‘No . . . and neither should the others, eh? But they needed that ice very badly.’
Now Setterholm’s voice held a tone of dull resignation. ‘For the reactor, you mean?’
‘Yes. The fusion plant.’ Clavain allowed himself to feel some small satisfaction before adding, ‘Actually, it was Galiana who made the connection, not me. That the reactor ran on ice, I mean. And after all the outlying bases had been evacuated, they had to keep everyone alive back at the main one. And that meant more load on the reactor. Which meant it needed more ice, of which there was hardly a shortage in the immediate vicinity.’
‘But they couldn’t be allowed to harvest the ice. Not after what I’d discovered.’
Clavain nodded, observing that the reversion from Iverson to Setterholm was now complete.
‘No. The ice is precious, isn’t it? Infinitely more so than anyone else realised. Without that ice the worms would have died—’
‘You don’t understand either, do you?’
Clavain swallowed. ‘I think I understand more than the others, Setterholm. You realised that the worms—’
‘It wasn’t the damned worms!’ He had shouted - Setterholm had turned on a loudspeaker function in his suit that Clavain had not yet located - and for a moment the words crashed around the great ice chamber, threatening to start the tiny chain reaction of fractures that would collapse the whole structure. But when silence had returned - disturbed only by the rasp of Clavain’s breathing - nothing had changed.
‘It wasn’t the worms?’
‘No.’ Setterholm was calmer now, as if the point had been made. ‘No - not really. They were important, yes - but only as low-level elements in a much more complex system. Don’t you understand?’
Clavain strove for honesty. ‘I never really understood what it was that fascinated you about them. They seem quite simple to me.’
Setterholm removed his weight from Clavain and rose up onto his feet aga
in. ‘That’s because they are. A child could grasp the biology of a single ice-worm in an afternoon. Felka did, in fact. Oh, she’s wonderful, Nevil.’ Setterholm’s teeth flashed a smile that chilled Clavain. ‘The things she could unravel . . . she isn’t a failure; not at all. I think she’s something miraculous we barely comprehend.’
‘Unlike the worms.’
‘Yes. They’re like clockwork toys, programmed with a few simple rules.’ Setterholm stooped down and grabbed the ice pick for himself. ‘They always respond in exactly the same way to the same input stimulus. And the kinds of stimuli they respond to are simple in the extreme: a few gradations of temperature; a few biochemical cues picked up from the ice itself. But the emergent properties . . .’
Clavain forced himself to a sitting position. ‘There’s that word again.’
‘It’s the network, Nevil. The system of tunnels the worms dig through the ice. Don’t you understand? That’s where the real complexity lies. That’s what I was always more interested in. Of course, it took me years to see it for what it is—’
‘Which is?’
‘A self-evolving network. One that has the capacity to adapt; to learn.’
‘It’s just a series of channels bored through ice, Setterholm.’
‘No. It’s infinitely more than that.’ The man craned his neck as far as the architecture of his suit would allow, revelling in the palatial beauty of the chamber. ‘There are two essential elements in any neural network, Nevil. Connections and nodes are necessary, but not enough. The connections must be capable of being weighted; adjusted in strength according to usefulness. And the nodes must be capable of processing the inputs from the connections in a deterministic manner, like logic gates.’ He gestured around the chamber. ‘Here, there is no absolutely sharp distinction between the connections and the nodes, but the essences remain. The worms lay down secretions when they travel, and those secretions determine how other worms make use of the same channels; whether they utilise one route or another. There are many determining factors - the sexes of the worms, the seasons, others I won’t bore you with. But the point is simple. The secretions - and the effect they have on the worms - mean that the topology of the network is governed by subtle emergent principles. And the breeding tangles function as logic gates; processing the inputs from their connecting nodes according to the rules of worm sex, caste and hierarchy. It’s messy, slow and biological - but the end result is that the worm colony as a whole functions as a neural network. It’s a program that the worms themselves are running, even though any given worm hasn’t a clue that it’s a part of a larger whole.’
The Revelation Space Collection Page 343