The floor of the cave was treacherous, with massive slabs of steeply slanting rock, and piles of rubble where parts of the ceiling had collapsed. Yet, taken as a whole, the cave was remarkably orderly. It ran upslope in roughly a straight line, and while the walls were made of jagged lava, the passage itself was still regular enough that it might have been drilled out of the original rock.
Ord scrambled ahead, looking for the best path. Skye hurried to keep up, thankful for the cold breeze in her face that assured her there was another way out. At one point they came to a Y-shaped junction, where the cave branched in two directions. Ord hesitated, its tentacles spread as it tested the air. Then it scurried down the left side.
“What exactly is a lava tube?” Skye asked.
Ord replied, “City library does not respond.”
“Oh. The radio signal can’t get out of this cave.” Never before had Ord failed to answer such a simple factual question. It gave her a strangely vulnerable feeling.
They walked on for another fifteen minutes. Finally, Skye was able to make out a gray glimmer in the distance. The light brightened as they approached. It fell from overhead, onto a cone-shaped pile of tumbled rocks, twice as tall as her own considerable height. The light had an odd, gray-green quality. She approached the site with a growing sense of gloom.
Clearly, the cave roof had fallen in, creating the pile of rubble and opening up a skylight to the outside world. The trouble was, the cave roof was at least ten meters overhead. Climbing the pile of rubble would get her halfway there, but she would still be a long way from getting out.
Ord said, “A lava tube is a channel formed by fast-moving lava when the surface of the flow cools and hardens. This crust insulates the superhot lava beneath, which continues to flow, sometimes for days. When the eruption stops, the lava drains out of the channel, leaving behind a long, tubular cave.”
Skye smiled. “Are you in contact with city library again, Ord?”
“Yes Skye.”
The cave continued on past the skylight. No telling how far. She squinted into the darkness, wondering if it was worth pushing on. “What do you think, Ord? Is there another entrance farther up?”
“Good to check,” Ord said, and scrambled away.
While it was gone, Skye climbed the rock pile, pausing every few steps to listen for Devi or Zia calling. She heard nothing. She reached the top of the mound and balanced there, gazing up at a canopy of leaves in a hundred shades of green. A flock of small red flyers fluttered and darted through the branches. The day seemed very dim. No sunlight glinted between the leaves, and after a minute she realized that a heavy layer of clouds had gathered across the sky.
Ord reappeared. “No good, Skye. Bad air.”
“Okay, Ord. Then we get out this way.”
It occurred to her she could toss Ord out. It could sample any mounds in the neighborhood. The job would be done. Then she could just wait here until rescue arrived.
Of course then Buyu would be in deep, deep trouble for losing her. Maybe he already was, but she would hope for the best. She would hope city authority hadn’t yet noticed that anything was wrong.
She drew in a deep breath, then yelled as loudly as she could, “Zia!” Her voice echoed off the cave wall and off the trees, and the red flyers scattered. “Zia! Devi! Buyu!” Again the echoes rolled away.
This time though, someone answered, sounding not too far off. “Skye?”
“Devi! Down here! Watch out for a big hole in the ground!”
“Keep talking, Skye! I’m following your voice.”
“Here. I’m over here, but I can’t get out. Are you all right? Where’s Zia?”
“Right here,” Zia said, sticking her head over the rim of the hole. She had dirt and bits of leaves stuck in her wiry hair, but her usual good humor had returned. She grinned at Skye’s predicament. “You look like some kind of goddess on her altar . . . only the ground fell out from under you.” She snickered.
“Ha ha. How am I going to get out of here?”
Devi’s head appeared beside Zia. He had lost the tie for his ponytail; his red and blond hair fell forward over his face as he looked down. He shoved one side of it behind an ear. “Are you all right?”
“Sooth. How am I going to get out of here?”
Buyu said, “I’ve got a rope.”
She turned to see him standing at a low point on the rim of the skylight. He had dropped his pack at his feet. Now he uncoiled a strand of orange rope. As he lowered it into the cave, loops sprouted every half meter along its length. Skye scrambled down the pile of rocks, but Ord reached the rope first. “Check for safety, Skye.” It scrambled up the line, testing each loop as it formed.
“We’re set,” Buyu called down. “Climb up when you’re ready.”
“Sooth. I’m coming now.”
Each loop hardened as she touched it, making a perfect step. It was an easy climb. When she reached the point where the rope lay against the rim of the skylight, each loop arched up a little, so she could get her fingers all the way around it. In a few more steps, she rolled out onto a padding of fallen leaves, and laughed. “What an adventure! Buyu, I couldn’t believe it when you took control of that warden. It was amazing!”
“The whole thing was stupid,” Buyu snapped. He held up his finger and thumb, only a centimeter apart. “You came this close to being lunch for that viperlion. When was the last time you updated your personal record?”
She couldn’t remember. What did it matter? She’d gotten away. Though Buyu was right—it had been close. “It bit my foot,” she said, sitting up. “The skin suit hardened.”
“The skin suit wouldn’t have saved you if it had gotten its maw on your skull. Did it ever occur to you to put your hood up? Coming down here was a big mistake. Only dumb ados would come up with a plan like this. No wonder they didn’t want me on an exploration team!”
She stared at him in shock. She had never seen Buyu angry before. He was certainly showing an unwelcome range of emotions lately. She looked to Zia and Devi for help. Devi only looked confused. Zia nodded. “Take it easy, Buyu. It may not have been the most elegant plan, but it worked.”
“That’s right,” Skye said. “Don’t forget why we’re down here.”
“You should be in the monkey house,” Buyu countered.
Her temper snapped. “Gutter dogs! Buyu, the mounds were your idea, and it was a good idea. It’s still a good idea, so let’s do it while we have the chance. Okay?”
He looked like he wanted to argue, but there was no good argument to make. He nodded. “All right. I saw a mound about twenty meters down the ridge.”
They had just set out when a pattering sound swept across the canopy. Skye looked up, curious and a little concerned. “What—?” Droplets of water splashed on her face and she ducked her head, spluttering.
“Rain,” Buyu said.
Devi held out his hands to feel the fat, cold drops falling off the trees. On his face was a look of wonder. “Rain. This is so wild! Water, just falling out of the sky.”
Skye wiped the water off her face, but more kept falling from the leaves . . . or from the clouds, that was it. Rain. She had seen rain in virtual reality stories, but she had never felt it before. It was cold, and she wasn’t sure she liked it.
They found the mound a minute later. It was small, only about half a meter across and knee-high. It looked like it was made of matted soil, or half-rotted mulch. Nothing grew on its surface. Mounds were nanotech factories, and they were said to be hot. She laid her gloved hand against it. The glove translated the feel of anything she touched; raw heat soaked into her palm. The mound had to be at least fifteen degrees above human body temperature. A light mist steamed off its surface as the rain struck.
Mounds were Chenzeme devices modified by the Well governors. They were supposed to collect data on human beings . . . and the plagues that could affect them? Skye hoped so. “Okay Ord,” she said, stepping back at last. “It’s up to you now. Can you find evidence of the Compassion plague? And can you find a cure?” Among all the long, green, data-bearing molecules that crawled through the Well’s biosphere and colored its water, there had to be some smart molecular machine that could defeat the Chenzeme nanotech weapon she carried in her cells.
“City library agrees it is possible,” Ord said. “Skye is very smart to know this. Good Skye.”
“Now, Ord.”
“Yes.”
She looked at Devi. He smiled encouragement. Then he nudged Buyu. They exchanged a strange look. Then they stepped back several paces. Skye frowned suspiciously, but she was distracted by Ord as it explored the mound, gingerly touching it with the sensitive suction cups at the ends of its tentacles. Finally, it rolled the end of one tentacle into a sharp spear point and pierced the mound. There was a hiss, as a horrible odor erupted from the wound. Skye hadn’t thought anything could smell worse than the stink Ord had released in the tunnel, but this – it was worse. She screamed in disgust and scampered away, crashing into Zia in her haste to escape the stench. “Oh, help me,” Zia moaned, falling dramatically to her knees. “Even Ord’s farts don’t smell that bad.”
Upslope and upwind, Devi was half bent over with laughter, while Buyu wore a twisted smile, as if he were trapped between guilt and amusement. “You knew!” Skye accused. “You both knew Ord would pop open that stink.”
“Sooth,” Devi grinned. “I did some reading on mounds last night. They present some interesting questions.”
“Yeah? Question this!” She scooped up a handful of humus and half-rotted leaves from the wet forest floor, and threw it at him. He dodged, and dove laughing behind a fallen log covered in green and brown moss. Skye raced up the slope with another clump of humus in hand and slammed it down on the backside of the log . . . then peered over to see the results of her work. But Devi was gone.
Uh-oh.
The counterassault fell before she could scramble away: a tall shrub leaning over the log started to shake violently, showering her in huge drops of water. “Gutter dog,” she growled, swiping her wet hair out of her face.
It wasn’t even noon yet, but she felt exhausted. Giving up, she sat down with her back to the log, looking at Ord as it balanced motionless on the mound, its tentacle jabbed deep inside the structure. Buyu was sitting on the ground drinking water and looking a little lost. Zia was pulling some rations out of his pack. “Here,” she said. “Eat something.” She tossed a packet toward Skye but it went wide. Devi’s hand, gloved in olive-green, reached out to catch it with a sharp smack. He leaned over the log and handed it to her. “For you, my lady.”
“Thanks.”
His red and blond hair was dripping wet. It fell half across his face as he looked at her in concern. “Are you okay?”
“Sooth.” She lied. In truth, she was feeling seriously tired, and a little dizzy. “You?”
He caught another packet from Zia and climbed over the log. Then he sat down beside her. “I look at you sometimes, and I get a little scared.”
“I look that bad?”
He smiled. “Hey Ord,” he called. “Find anything?”
“Yes Devi. Many plague vectors and associated antibodies. Much Earth-clade genetic data. Also, information storage systems and—”
“Have you found what we’re looking for?” Devi interrupted.
“City library says yes.”
At first Skye wasn’t sure she had heard right. Then a hot flush of relief rushed out of her pores. She closed her eyes and tipped her head back against the log, realizing for the first time just how really scared she had been.
“Hey.”
She opened her eyes and turned to look at Devi. With his long, wild hair falling over his tanned face, he did not look much like the mannered astronomer she had met on a rooftop just last night. He gazed into her eyes and he said, “You’re okay. You understand? It’s all going to work out.”
She nodded, blinking back a sudden, frightening surge of tears. The lifeboats were out there, she was sure of it. And if Ord was right, then the Compassion plague they carried wouldn’t be a threat to anyone anymore.