The Frozen Sky Read online

  The next time, the sunfish had dropped three tons of rock on NASA’s probes before swarming the sole survivor. Attempts to communicate via sonar and the sunfishes’ shaped-based language were ignored.

  NASA had tagged four sunfish with nano darts, expecting to monitor the tribe with these beacons… but the sunfish tore open the infinitesimal holes in their skin, then bared their wounds to their comrades, who chewed into their flesh before regurgitating the gory meat. The biologists agreed the sunfish were extremely sensitive to parasites. That indicated a prevalence of other bugs or microorganisms as yet undiscovered. On Europa, it appeared, pests and disease were as virulent as the higher lifeforms. Contagion and blight might have done as much damage to the sunfish empire as volcanic upheavals.

  “Here’s what’s driving me crazy,” Metzler said, opening a sim full of mathematics. Vonnie recognized some of the data as Lam’s.

  “There’s not enough food in the biosphere for predators their size,” she said.

  “Not by a third.”

  “We know they’re omnivores. They could get a lot of the mass they need from vegetation.”

  “What kind of vegetation? We haven’t found anything more advanced than fungi, and I don’t think we will. Not without photosynthesis. There won’t be anything like terrestrial plants or algae.”

  “Maybe sunfish don’t need as many calories as we would if we were their size,” Ash said. “Couldn’t their intake be explained by a difference in Europan metabolism?”

  “If they hibernated for extended periods, I’d say yes,” Metzler said, “but their genome doesn’t show protein expression patterns that resemble anything like hibernating species on Earth. The only behavior we’ve recorded has been sustained activity. They never stop. They don’t even sleep.”

  “I’ve seen them rest,” Vonnie said, remembering the very first group of sunfish she’d met.

  “That was in a low-atmosphere environment with almost zero oxygen,” Metzler said. “We think they were harvesting fungal spores from the rock. They were moving at half-speed to conserve their time in the area. Uh, they also might have bled one of their friends for the oxygen in his system.”

  “What?”

  “We’ve put together a few sims using your files. At the back of the crevice, it looks like they were holding down the smallest sunfish. They were drinking from him. Then he might have been dinner, too.”

  “God.” Vonnie shook her head. “That would fit with their pack mentality, but you’re making a lot of assumptions.”

  “Yeah. Presumably there are more diverse food chains further down, or the sunfish are farming somewhere we haven’t found yet, or both. It would be fantastic if we could get some mecha down to the ocean. A lot of our answers will be there.”

  The ocean, Vonnie thought. “Have you asked Koebsch? There are soft spots on the equator where the ice is only five kilometers thick. We could drill through.”

  “It’s under consideration. We already have our hands full.”

  She smiled at the understatement. Earth had dispatched another high-gee launch loaded with new mecha and supplies, but the ship was piloted by an AI. They didn’t foresee adding more people soon. The costs were too steep.

  “Tell me about Tom,” she said.

  “Our star pupil.” Metzler opened a new file without playing it. “Listen, I should’ve warned you not to get your hopes up. What happened this morning was incremental at best.”

  “You might get another kiss anyway.”

  “Oh. Okay.”

  “Would you two knock it off?” Ash said, but her tone was encouraging, and Vonnie was glad to be teased. Their friendship made the sunfish less intimidating.

  She still had nightmares.

  The emotions she felt toward the sunfish bordered on awe and reverence, but she still had bloody nightmares.

  Surface of the Southern Pole Map

  31.

  Constructed mostly of ceramics, ESA spies were stealthed against radar, X-ray, and infrared. That served them well in tracking the Brazilians, who hadn’t mastered neutrino tech and couldn’t buy it, since none of the major powers had made their neutrino instruments for sale.

  Unfortunately, the sunfishes’ sonar abilities were exquisitely honed. There was no way to hide smooth, rounded objects from them — not even objects as small as a pill.

  The ESA’s answer had been to house each spy in a rough camouflage shell. Wearing these shells, which included real water or native basalt, the spies possessed the same reflective signature as ice or rock.

  Advancing through the catacombs, the spies had begun to gather useful information before they came within .5 km of the sunfish, discerning activity by vibrations and sonar calls. Then the spies had approached within a few hundred meters, and their datastreams grew richer.

  “The sunfish are moving in fours just like the rows of carvings,” Vonnie said. “Look how they stay together.”

  “I don’t see it,” Ash said.

  “Watch.”

  There were twenty-three sunfish within range of the spies’ array. They scurried and pounced through thirty meters of tunnel. Some of them shoved hunks of lava into the air like baseballs or bricks. Others collected these missiles against one wall. In between, more sunfish dragged larger rocks across the floor.

  Vonnie was struck again by the alien beauty of this environment. There were hot spots spread through the rock measuring a toasty -46° to -41° Celsius. Those temperatures were far below freezing, but enough heat had radiated through the spongy old lava to bake the few water molecules in the area. Then the moisture had recondensed. Film-thin drips of ice speckled the tunnel floor. In radar, the ice looked like bright coin— but as always, it was the lithe, powerful sunfish who fascinated her.

  They were nearly uniform in size and skin texture. Tom had his crippled arm. Sue and nine others wore scars or bite marks. Otherwise they appeared to be an indistinguishable swarm, yet that was an illusion.

  Lost in the ruckus was an astonishing degree of coordination. Not one of the sunfish were ever hit or caught off-guard by the missiles. On the tunnel floor, despite rushing back and forth, they did not trample their comrades.

  Vonnie tapped at Metzler’s pad, superimposing a color code on the sunfish. She started with Tom. Near the edge of the group, he struggled with three others to pry loose a desk-sized section of rock, ignoring two more sunfish who hopped into his work space and bounced away in order to throw smaller bits of lava across the tunnel.

  “Tom’s diggers are blue,” Vonnie said. “The scavengers who passed through his team are red, this group is yellow, and here’s purple, green, and orange.”

  “Twenty-three isn’t divisible by four,” Ash said.

  “Green is one short,” Vonnie said. “That’s probably why they paired with orange to do the heavy lifting. Look at what’s happening. They spread apart and mix together, but they constantly reform in the same quartets.”

  “We think they have a compulsion toward fours and eights, which is what you’d expect given their physiology,” Metzler said. “Their math is probably based on sums of eight like ours is based on tens.”

  “They’re building something,” Vonnie said.

  The sunfish weren’t crudely stacking rock against the side of the tunnel. They worked expertly on a column as well-fit as a puzzle, using shape and weight to hold this mass. Each sunfish also left urine or dung in key places. Their waste would freeze like adhesive.

  “It’s not a shelter,” Vonnie said. “It looks like a retaining wall, but it’s in the middle of nowhere. Why are they here? There’s no food. No water. The air’s barely any good. Is anything behind that side of the tunnel?”

  “We’re not sure. It’s warm. We think there’s a channel of magma not too far away.”

  “We need to get a probe close enough to scan through the rock. Maybe there are hot springs on the other side, or bacterial mats, or their home. Do they have an air lock nearby?”

  “We don’t know.�
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  “Right.” Vonnie clenched and unclenched her hands, her nerves flickering with anticipation.

  Where were sunfishes’ children? Did they protect them like humans protected their young or were their eggs left to live or die like those of Earth’s frogs and fish? She wanted the answer to be the first possibility. More likely it was the second.

  From gene sequencing, X-rays, and her mem files, the biologists said the packs of sunfish included both males and females. The females were physically larger, less in number, and seemed to dominate, calling out more often than the males.

  Every one of these physical and sociological aspects were the opposite in humankind. Homo sapiens had typically banned their females from hunting and combat until very recently in history, when technology had provided women with as many advantages as men.

  It was another clue to the sunfishes’ mentality. Each time a group left home, they brought enough fertile adults to persevere if their colony was annihilated behind them.

  The biologists also knew the sunfish didn’t gestate their unborn because they had no wombs. They laid spawn — hundreds of eggs at once — which the males either sprinkled with milt during the act of laying or soon afterward.

  The sunfish might have mating rituals, but they did not make love. They might not have a sex act at all. Equally significant, because they were warm-blooded and semi-aquatic, they probably laid their eggs in hot springs. There was no sunlight to incubate their spawn. They relied on the environment as part of their reproductive cycle, but the environment was catastrophic.

  Metzler theorized that the females felt no attachment to their spawn, only bonding with successful newborn. They were predisposed to abandon their eggs.

  Nature seemed to have compensated. If the gene smithing of the sunfishes’ hormones was correct, their females laid spawn as often as six times in an Earth year. That was a staggering birth rate. It could have meant disastrously high population pressures, except most of the eggs never became adults. Maybe they ate their failed spawn or performed infanticide to weed out their weaker offspring.

  That doesn’t mean they’re not affectionate, Vonnie told herself. The sunfish huddled for warmth, cared for each other’s wounds and infections, and there was poetry in the fluid, detailed ruffling of their arms and bodies.

  Did they know joy?

  They seemed well-suited for a love of life. They moved like birds or dolphins. They built and succeeded. But they were short-lived. Their telomeres indicated an average lifespan of no more than twenty years.

  By now, ESA and NASA biologists owned samples from seventeen different sunfish, dozens of bugs, and any number of bacterial mats and fungi. Most of the blood and tissue had been gathered from Vonnie’s suit. Five more blood pricks had been secured by NASA’s probes during the past week, and it was a toss-up which set of samples had caused the loudest uproar.

  The botanists, entomologists, exobiologists, and gene smiths each had different arguments that their results were the most spectacular.

  Europan DNA wasn’t wildly distinct from Earth DNA. The sunfish genome was composed of sequences using the same four nucleic acids as terrestrial lifeforms. The one difference was in their blast scores for hemoglobin. The sunfish had evolved with a remarkable concentration of iron atoms in this globular protein, which allowed them to carry extra oxygen through their bloodstream.

  The sunfish also had little genetic variation from each other. They were nearly clones, like cheetahs, which was another species that had been reduced to a bare minimum of breeding pairs in its past.

  “Tell me what happened with Tom,” Vonnie said.

  “It was hours later,” Metzler said, forwarding through his sim. “The sunfish ran out of material for their wall. They sent scouts into the side channels, including his team. Tom seems to go farther than anyone else. They might consider him expendable because of his injuries. Maybe he’s earned a leadership role for being so resilient. I don’t think most of them would have survived losing part of an arm.”

  “They’d eat him,” Ash said.

  “Yeah.”

  Metzler’s recording showed Tom leap into view at a steep angle from the tunnel floor to its ceiling. He flew with his arms spread, screeching at the space ahead of him. Then he landed on a crag in the rock and stuck to it, bunching his arms with his body poised like a rocket, ready to jump again.

  He’d obviously sensed 112, which sat twenty meters away. In flight, Tom had wavered in a clockwise motion, bending back each of his arm tips, including his stub. Curling inward might have pantomimed grabbing at the probe or bringing an object to his beak. This motion was a gesture more like releasing something.

  “That means ’Hello’ or ’Yes’ depending on the context,” Metzler said. “We found the same pose at the center of every wall of carvings. It’s a starting place. The sunfish don’t read in straight lines like we do. We think they read outward from the ’Hello’ stance.”

  “I saw Pärnits’ report,” Vonnie said absently, staring at the display. Then she glanced at Metzler, wondering why she’d mentioned his friend’s name.

  He knew she was also dating Pärnits. Was the instinct to test potential mates so innate that it had spoken for her? Vonnie wasn’t coy, and she wasn’t mean, and yet she’d just undermined Metzler by giving credit to Pärnits.

  Awkwardly, she scrambled to make up for it. “These sims are amazing,” she said.

  “Well, here’s where everything goes wrong,” Metzler said.

  Was he annoyed with her?

  Probe 112 repeated the ’Hello’ gesture, then showed the undersides of two arms, undulating its pedicellaria.

  It didn’t have the effect they’d intended.

  Tom lifted his underside to show his beak, a hostile gesture. He screeched into the catacombs behind him, alerting his companions. As soon as they answered, he turned and called in the probe’s direction. Most likely he was scanning for other strangers. Possibly he was shouting threats at the probe not to come any closer.

  “What if we’re putting Tom in danger by talking to him?” Vonnie said. “The other sunfish might not like it.”

  “Jesus, you’re strange,” Ash said. From the way her hazel eyes searched Vonnie’s face, she was only half kidding. “I know you have a huge crush on those monsters. Now you’re more on their side than ours?”

  “None of us want him to get hurt.”

  “It’s a chance we have to take,” Frerotte said. “If we’re going to talk to them, we have to start somewhere.”

  Tom finished screeching into the dark. He leapt away from 112, escaping it but not the camouflaged spies, who recorded his flight. First he rejoined his quartet. Then they formed up with the rest of the pack.

  At the same time, Probes 112 and 113 fled.

  When the sunfish returned in force, the probes were gone. The sunfish clung to the rock. They did not pursue. Instead, they screamed at the empty tunnel.

  “What are they doing?” Ash said.

  “That looks territorial,” Vonnie said. “They’re claiming this space.”

  “We thought so, too,” Metzler said. “Their sonar would carry after the probes for a long way, maybe as far as three kilometers. Watch what they do next.”

  The sunfish quit screeching. They returned to the tunnel where they’d built their wall. Then they assembled in a pack and began screeching again, using the rock to amplify their shrill voices back on themselves.

  Ash put her hands over her ears. “They’ll go deaf!”

  “They’re worried the probes will try to flank them,” Vonnie said. “Remember, they’re always exposed on all sides, up and down. So they’re repeating the warning.”

  “It seems more intense than that,” Metzler said. “What if it’s an affirmation ritual? They could be promising each other to defend the colony or memorizing a new voice key. Look at their modulation. They’re not just screaming. There’s a carefully refined harmony.”

  “Why did Tom run from the probe?”r />
  “We’re not sure. They must find loners or survivors from other packs sometimes.”

  “They probably eat them, too,” Ash said.

  “Maybe not. Survivors from another area could lead them to new food supplies or thermals. There’s also a biological imperative. Accepting newcomers into the pack would be good genetics. They need the diversity.”

  “Maybe the probe said the wrong thing,” Ash said.

  “I don’t think so. It was docile. It responded to Tom’s overture.”

  “You did great,” Vonnie said, bumping his shoulder.

  “Pärnits programmed its secondary movements,” Metzler said. “Maybe something in those gestures was too abrupt or he used the wrong arms.”

  The subtext of that comment wasn’t difficult to interpret. Metzler had undercut his rival for Vonnie’s affections, opening a divide between the two men, which was exactly what she didn’t want.

  “This encounter went better than anything else we’ve done,” she said. “You guys are spectacular.”

  “We probably should have told the probe to stay,” Metzler said. “The sunfish would never accept a loner without assessing him as a group. That would also reduce their odds of sustaining casualties. If it’s a trap, if he’s sick or feeble, they’d smash him.”

  “Are we sure the probe had the right sound?” Ash said.

  With help from their gene smiths, Vonnie and Ash had grafted synthetic blubber and skin onto the probes’ exteriors. Naked metal wouldn’t sound like a living creature, nor smell like one. Metzler was certain that the hundreds of tube feet commingled with the sunfishes’ pedicellaria were a sensitive scent-and-taste organ. Even in areas where there was no atmosphere, the sunfish must be attuned to each other’s smell, the mineral content in the rock, toxins, moisture, and the tracks of anything that had passed before them.