While Orion dropped the chocolate cubes into their mugs, Ozzie started peeling one of the big bluish gray fruits they’d picked from the jungle. The pulp inside had a coarse texture, tasting like a cinnamon-flavored apple. It was one of eight edible fruits they’d discovered so far. Just like every other environment the Silfen paths led to, the reef was quite capable of supporting life.
Tochee emerged from the jungle, its manipulator flesh coiled around various containers it had filled with water. A small stream ran across the rumpled polyp ground fifty meters from their shelter, its water so clean they barely needed to use the filter.
“Good morning to you, friend Ozzie,” it said through the handheld array.
“Morning.” Ozzie took a drink of the chocolate.
“I have detected no electrical power circuit activity with my equipment.” The big alien held up a couple of sensors it had brought with it. “The machinery must be very deep inside the reef.”
“Yeah, you’re probably right.” Even after all this time spent together, Tochee hadn’t quite grasped the fact that Ozzie liked a bit of peace and quiet at breakfast.
“Where did you go?” Orion asked as Ozzie munched stoically on his fruit.
“Five kilometers in that direction.” Tochee formed a tentacle out of its manipulator flesh, and pointed.
“I think the middle is that way.” Orion pointed almost at right angles to Tochee’s tentacle.
“Are you sure?”
“I dunno. Where is it, Ozzie?”
Ozzie jerked a thumb over his shoulder. “There, nine kilometers.”
“I apologize,” Tochee said. “My instruments do not possess a navigation function like yours.”
“Did you see anything interesting?” Orion asked.
“Many trees. Some small flying creatures. No large or sentient life.”
“Too bad.” The boy cut a big slice out of a purplish fruit with his penknife, and bit into it eagerly. Juice dribbled down his chin, getting caught in his wispy beard. “Were there any caves?”
“I did not see any.”
“There’s got to be a way in to the core somewhere. I wonder if it’s right on the tip of the spires. There can’t be any gravity along the axis, that’s where it all balances out, Ozzie said so. I bet that’s just one long tunnel the whole length of this thing.”
“Logic would dictate the shortest distance. An access passage to the core would surely begin on the surface at the middle.”
“Yeah. I bet there’s a whole load of caves and stuff. It’ll be where the reef’s inhabitants live, like the Morlocks.”
Ozzie took another drink of chocolate, not making eye contact. He was already regretting telling that story.
“Do you still think something lives here, friend Orion?” Tochee asked.
“What’s the point of it otherwise?”
“I have seen no sign of any large creature.”
“No, ‘cause they’re underground.”
Ozzie finished his chocolate and retied his hair with a small band of leather so that it didn’t flop down over his eyes. “They are not underground,” he said. “You do not build islands in something like the gas halo, and then populate them with troglodyte species. Nothing lives here.”
“What’s a trogodite?” Orion asked.
“Someone who lives underground.”
“Excuse me, friend Ozzie,” Tochee said. “But this whole gas halo is lacking in logic. We might yet find some life belowground. Why else would you build islands in the sky?”
“Carbon sinks,” Ozzie said. “It’s all a question of scale, which is admittedly difficult to get your head around. Even I’m having serious trouble with this when I look up and see sky that goes on forever. But we know that there is a lot of animal life flapping around inside the gas halo. As it’s a standard oxygen-nitrogen mix it’s pretty safe to say they all breathe oxygen, and exhale carbon dioxide, or some other waste product. Now I’m sure it would take billions of years for all those animals to poison something as gigantic as the gas halo, but it will happen unless the opposite process is active. You can either do it artificially, with machines; or the green way, with plants. And that’s what this reef is, a part of the ecosystem. It probably doubles as a food garden and watering hole as well. The air-desert equivalent of an oasis.”
“You said there was machinery inside it,” Orion said, his tone accusing.
“There is some kind of gravity generator, certainly, man, and that probably has a steering function; I’m pretty sure it was put on a collision course with us. The rest of it is all biological.”
“What’s the point if they can clean the air with machines?”
“I suspect they built all of this just for the hell of it, man, the enjoyment of living in something so utterly fantastic. I know I would if I could. I already did something like this on a minuscule scale back home.”
“Did you?”
“Very small scale, yeah.”
“What?”
“It’s an artificial environment; nothing special, not important. Look, the reason I’m interested in trying to locate the gravity generator in this reef is because I might figure out how to use it to steer us somewhere.” He held a hand up to stall both of them. “And no, guys, I don’t know where yet, but a degree of control would be useful at this moment in time, okay? We really are out of all other options.”
“You said that back on the water island.” Orion’s grin was pure disrespect.
“Shows you how little I know. Come on, Tochee’s probably right about the inspection hatch being close to the center. Let’s go see if we can find it.”
The intricacy of the reef’s jungle fascinated Ozzie; it was a work of art. There was a near-uniform gap between the ground and the first level of branches of about four meters. Just right for a human or a Silfen to walk comfortably in the low gravity without hitting their head on branches. In fact, if you happened to push off too hard the lacework of branches and twigs was dense enough for a simple slap of the hand to help flatten out the arc of your glide-walk. An overhead safety net, basically. Ozzie was convinced that was deliberate. So if the trees weren’t pruned, and he’d seen nothing to indicate they were, they must have been configured at a genetic level to grow like that. Even for a society with the resources to build the gas halo, that was a lot of work.
There was plenty of variety, too, ranging from trees that could have come direct from the forest of any H-congruous world, to the bizarre purple chimneylike tubes, as well as a host of alien species like the flexible globular lattice that Orion had landed in. Ozzie half expected to see a ma-hon growing amid the profusion of exotica.
Covered by the thin layer of loam was an equal diversity of polyp strata, dull ash-gray bands interlocked with stone-brown bulbs and creamy intestinal clusters, knobbly gentian ropes and open-ended maroon cones with puddles of dank water lying at their base. Blue-speckled hazel protrusions in the shape of button mushrooms were common, although they were all over two meters in diameter.
Johansson had been right to call these creations reefs, Ozzie thought. The trees, as they swiftly realized, lived in perfect symbiosis with the polyp. There was no deep layer of soil to support the roots; instead they were supplied with water and nutrients by the coral itself. In return it must slowly absorb the loam formed by their fallen, rotted leaves to regenerate itself.
There were glades, wide patches where no trees grew, filled with bright sunlight. Here the thin sandy soil sprouted a few tufts of grass, or straggly plants giving a curious impression of lifelessness amid the luxuriant growth of the jungle. Each time they came across such a feature they stayed close to the fringe of trees, as if they’d grown afraid of the empty sky.
Ozzie was pretty sure he knew where such uncertainty rose from. Anything could exist in the gas halo, descending on them without warning out of that infinite blue expanse.
“Do you think there are paths here?” Orion asked. “You said Johansson walked back to the Commonwealth from a reef.”
“There could be,” Ozzie admitted. Indeed he was carrying his rucksack in case they did wander onto the start of a path. He’d insisted on the boy and Tochee carrying their essentials as well. They had so little equipment and supplies left they simply couldn’t afford to lose any more. Deep down, he was hoping they really would start the long walk off the reef midway through one of these expeditions. That yearning was a direct reaction to his circumstances. All he was focusing on these days was simple survival. He’d been traveling for so long now he had grown terribly weary of it. The starship had surely flown to the Dyson Pair and returned by now. It was a depressing thought that the answer would be waiting for him when he returned home, a brief historical note within the unisphere.
When he did catch himself indulging in such wistful speculation he grew angry. After enduring so much he deserved to find the adult Silfen community.
“I know when we’re on a path these days,” Orion said. “I can feel it.”
“I believe I may share that awareness,” Tochee said. “There is no logic to the knowledge, which is difficult for me, but I sometimes find an inner certainty.”
Ozzie, who had possessed that particular trait for some time, kept quiet. The really good thing about getting home would be dropping Orion and Tochee off in a decent hotel and getting the hell away from their constant inane chatter.
The handheld array reported they were drawing near to the geometrical center of the reef; it was hard to define the exact point outside of an area a couple of hundred meters in diameter, although they were certainly halfway between the tips of both end spires. A good visual clue was in the size of the trees, which were getting a lot taller. Why, though? Is the center the oldest part? That doesn’t make a lot of sense. Nonetheless, their trunks were massive here, several meters across, leaving the ground directly beneath them arid and dusty. The surrounding polyp had cracked, with long dead flakes lifting up like jagged teeth around the bark. Overhead, the ceiling of branches and leaves was so dense that the light had reduced to a pale uniform gloaming.
“It’s lighter up ahead,” Orion said. A glare of sunlight was filtering past the trunks. They walked toward it, squinting after so long in the gloomy silence of the great trees.
The light came from a clearing over a kilometer wide. For once there was a blanket of greenery covering the ground, a plant as tenacious as ground eldar but with slim ankle-high jade-green leaves that rustled like rice paper. A fence of the purple polyp tubes formed a neat perimeter, towering above the thick trees, each one curving around high above them so their ends were aligned horizontally out across the reef.
“They’re chimneys!” Orion declared. White vapor was oozing out of each one, twirling away above the treetops. Ozzie recalled the odd riverlike ribbons of cloud
