“Then shut up until you’ve got something constructive to say.”
They were kilometres into the second layer of Cerberus now; good progress by some yardsticks, since they had descended more vertical distance now than the tallest mountains on Earth—but it was still too slow. At this rate they would never make it back in time, if they even succeeded in reaching whatever destination they were striving towards. Before then, the bridgehead would surely have given in to the tireless expulsive energies being directed against it by the crustal defences, and it would be digested or spat away into space like an unwanted pip.
The second layer—the bedrock on which the snakes writhed, and into which the roof-supporting trees thrust their roots—had a crystalline topography, markedly different to the kind of quasi-organic look of the overlying structures. They had been forced to thread their way downwards in the narrow interstices between the densely packed crystal forms, like ants navigating between courses of brickwork. It was slow work, and it quickly depleted the suits’ reaction reservoirs, since all the downward movement had to be constantly checked by thrust. At first Sylveste had suggested that they use the monofilament grapples which the suits could deploy (or grow, or extrude; he did not bother himself with the details), but Sajaki had argued him out of it: it would have conserved reaction mass, but it would also have greatly delayed their descent, since hundreds of kilometres still lay below them. Apart from that, it would also have limited them to strictly vertical motion, which would have made them easy targets for hypothetical counter-insurgent systems. So they flew most of the time, stopping when necessary to ablate small quantities of Cerberus material. So far, Cerberus had not objected to their vampiric activities, and the crystals contained enough heavy trace-elements to feed the thruster reservoirs.
“It’s as if it doesn’t know we’re here,” Sylveste said.
Calvin answered him. “Maybe it doesn’t. Not much can have reached this far down in living memory. The systems designed to detect intruders and defend against them might have atrophied through disuse—assuming they ever existed in the first place.”
“Why do I have the impression you’re suddenly trying to cheer me up?”
“I suppose I have your best interests at heart.” He imagined Calvin smiling, though there was no visual component to the simulation. “In any case, I believe what I just said. I think the deeper we go, the less likelihood we’ll have of being recognised as something unwanted. It’s like the human body—-the greatest density of pain receptors lies in the skin.”
Sylveste remembered a stomach cramp he had once experienced through drinking too much cold water during a surface hike out from Chasm City, and wondered if there was even a glint of truth in what Calvin had just said to him. It was reassuring though; of that there was no doubt. But did it also mean that everything deeper would be half-sleeping; as if the mighty defences of the crust were now meaningless, because what lay below no longer worked as the Amarantin had intended? Was Cerberus a treasure chest which, though firmly locked and burnished to a high polish, contained nothing but rusting junk—if that?
There was no sense thinking that way. If any of this meant anything, if the last fifty years of his life (and perhaps even more than that) had been anything other than delusional obsession, there had to be something worth finding. The feeling was nothing he could articulate, but he was more sure of it than he had ever before been sure of anything.
Another day of descent passed; during intervals Sylveste slept, being awakened by his suit only when something notable occurred, or the external scene changed beyond some inbuilt tolerance and the suit decided that he had better be awake to witness it. If Sajaki slept Sylveste was unaware of it, but he ascribed this to the generally odd physiology of the man; his blood thickened by medichines, constantly cleansing; his Juggler-configured mind able to do without the auditing hours of normal sleep. When the going was easiest, they descended at a maximum rate of one kilometre a minute, which usually happened when some deep abyssal shaft hove into view. The return would be quicker, of course, since the suits would know the way they had come, barring changes in the structure of Cerberus itself. Now it was not uncommon for them to descend for several kilometres before hitting a dead end, or a shaft too narrow for safety, at which point they would retreat to the last branch point and attempt another route. It was pure trial and error, since the suit sensors could not see more than a few hundred metres ahead at any point, blocked by the massive solidity of the crystal elements. But, kilometre by kilometre, they made slow progress, bathed always in sickly turquoise-green light spilling from the crystals.
Gradually the character of the formations had been altering; there were shards here many kilometres across, impassive and immobile as glaciers. All the crystals were attached to one another, but the vaultlike spaces and vertiginous rifts between them gave the impression that they were floating freely, as if in mute denial of the world’s gravitational field. What were they, Sylveste wondered? Dead matter—literally, crystalline—or something stranger? Were they components; parts of some world-englobing mechanism which was too large to be glimpsed or even imagined? If they were machines, they must have been exploiting some hazy state of quantum reality, where concepts like heat and energy dissolved into uncertainty. Certainly, they were as cold as ice (the suit’s thermal sensors told him this), and yet beneath their translucent faces he sometimes sensed tremendous subliminal motion, like the ticking guts of a clock glimpsed through a veil of lucite. But when he asked the suit to investigate with its senses, the results it sent back were too ambiguous to be much help.
After forty hours of rambling descent they made a significant and helpful discovery. The crystal matrix thinned out in a transitional zone only a kilometre deep, exposing shafts wider and deeper than any they had yet encountered; more deliberate in design. They were two kilometres in width, and each of the ten shafts they examined fell towards convergent nothingness for two hundred vertical kilometres. The walls of the shafts emitted the same slightly nauseating green radiance as the crystal elements, and they shivered with the same underlying sense of pent-up motion, suggesting that they were parts of the same mechanisms, though fulfilling some very different function. Sylveste remembered what he knew about the great pyramids in Egypt; how they were riddled with shafts which had been dictated by the construction technique; escape routes for the workers who sealed the tombs within. Perhaps something similar applied here, or perhaps the shafts had once served to radiate the heat of engines now quietened.
Discovering them was a godsend, since it enormously quickened their rate of descent, but that gift was not without its hazards. Constrained by the linear walls of the shaft, there would be nowhere to seek refuge if an attack came, and only two possible directions of escape. Yet if they delayed further, they would face imprisonment in Cerberus when the bridgehead collapsed; no more palatable a fate. So they risked using the shafts.
They could not simply fall. That had been possible before, when the vertical distance was no more than a kilometre or so, but here the very size of the shafts brought unanticipated problems. They found themselves drifting mysteriously towards the walls, and had to keep applying bursts of corrective thrust to stop themselves being dashed against the rushing precipice of sickly jade. It was Coriolis force, of course: the same fictitious force which curved wind vectors into cyclones on the surface of a rotating planet. Here, Coriolis force objected to a strictly linear descent, since Cerberus was rotating, and Sylveste and Sajaki had to shed excess angular momentum with each movement closer to the core. Yet compared to their earlier slow progress, it was gratifyingly rapid.