Cold as Ice

by Charles Sheffield

  "I can't," repeated Camille. "Without my models, and without a computer and all the parameters—"

  "You can. I know you better than you know yourself. Look inside, Camille. Don't you realize that you can always feel the answers, even before the computers come back with theirs? You understand fusion stability, even in complicated situations, without having to think about it. You've studied it and studied it until it's part of your deep subconscious. Look inside."

  "No." Camille was shivering. Hilda Brandt's eyes were enormous twin moons that filled the sky. Camille could not look away. "You're wrong, quite wrong. I calculate everything."

  "You do. But you don't need to calculate everything with the computers, because you are already doing it in your head. The computer solutions are just your security. If you don't like the look of their answers, what do you do? You run them again, until they are the way you feel they ought to be. You've talked to a lot of people about the 'shortcuts' that you use to get quick results. Use them now—when we need them."

  Camille could not escape. She could not even move. A terrible force, hot and imperative, was holding her to those luminous eyes. A voice, far away, was saying, "Fifteen minutes. You will have fifteen minutes."

  It said it again. A third time. On the fourth repetition, the Europan sky and landscape vanished. Camille slipped away into that strange interior domain of rippling plasma, hers alone, where no one else could ever follow.

  * * *

  The Moby, stripped of its accessories, was surprisingly small for its fifty-gigawatt output. A bright-blue rounded cylinder, two meters long and no more than half that across, it sat cradled in an upright frame, its broad end down. The open lattice of the supports, held in exact alignment by twin gyroscopes at its top, had been carefully placed in the center of Blowhole.

  David Lammerman was checking the Moby's power settings and nozzle diameters for the third time. He really needed to consult Camille on a fine point or two, but she had been led away, pale and close to fainting, as soon as her listing of Moby parameters was complete. She had stood motionless for twenty-five agonizing minutes—twenty-five, not fifteen—and not even Hilda Brandt had dared to interrupt her concentration. Finally she had called for an audio link and begun to define Moby settings as fast as she could speak.

  It was left to David to make those settings, and to worry that Camille's answers might be disastrously wrong. Suppose that the unknowns of local gravity or temperature proved more important than anyone realized? Had anyone, ever, examined such a direct plasma/water-ice interaction? He wanted to ask Camille about the effects on the Moby of the ambient high-energy particle flux, about latent heats, about conductivities, about radiation losses to the open space above Europa's surface. About everything.

  But time had run out. Somewhere beneath his feet—he wished he knew how far; if the Moby performed as planned, that depth was a crucial variable—somewhere down there, anything from fifty meters to a hundred kilometers below, Jon Perry and Wilsa Sheer were either dead or dying, from oxygen starvation.

  There could be no delays.

  David prepared to switch on. At his side, Cyrus Mobarak had observed his son in his task of calibration. Three times he had held out a hand to interrupt, three times drawn it back. He resisted the urge to take over and make his own check of Moby settings. The only exception was at the end, when he realized that David was within seconds of switching on. Mobarak began to urge everyone away from Blowhole.

  Hilda Brandt refused to move. She stood at the very edge of the circle of ice until David himself, his task complete, came across, grabbed her arm, and pulled her far from the perimeter.

  They watched and waited for fifteen endless seconds. David, sure that something must be wrong with one of his settings, started forward across the ice. Cyrus Mobarak's hand, suddenly firm on his arm, held him in place.

  "No," murmured a gruff, mesmerizing voice. "Low-order transients. Delaying the fusion cycle."

  David did not reply. He did not need to. For although there was nothing to see on the Moby itself, the ice in a fifteen-meter circle around it suddenly began to sputter and fume. A second later, a thick hemisphere of water vapor was forming. The Moby at its center became invisible in a cloud of white.

  "Is it working?" The voice over the suit radio was Tristan Morgan's, but it was barely audible above half a dozen others that were exclaiming as the vapor cloud turned blue at its spreading base.

  Everyone instinctively stepped farther back. The ice beneath their feet had begun to tremble, responding to an immense energy release. The Moby reappeared for a moment, lifted on a plume of violet flame. Then it began moving down, descending at a measured couple of meters a second.

  David strained forward, counting, waiting. He did not have Camille's quantitative understanding of processes, but he knew in general terms what was happening. The first critical point would come after seventeen seconds. Four concentric zones of activity must be stably established around the Moby. In the innermost one, the Moby plasma jets, hell fires at temperatures of hundreds of millions of degrees, impinged directly on the frozen surface of Blowhole. The ice beneath them did not melt or boil. It dissociated into monomolecular hydrogen and monomolecular oxygen. Those elements spread outward and recombined in the second zone with a violence more powerful than an ordinary chemical reaction. Ice at that point also dissociated, this time into ordinary oxygen and hydrogen, which burned in turn at a temperature of a few thousand degrees. The heat from this converted the next zone of Blowhole to superheated steam. It was this steam that in the fourth zone finally melted the outer perimeter of the column.

  Fifteen, sixteen, seventeen. The hole in the ice, if Camille were right, was now close to its maximum diameter. The Moby was beginning to drop at a constant rate, slicing a thirty-meter-wide core through the upper level of Europa's ice blanket.

  Twenty-three, twenty-four, twenty-five. An immense conical cloud, bursting almost straight up out of Blowhole, was lit from within by the infernal fires of stellar-temperature plasma. To an orbiting observer directly above, Blowhole would appear as a pinpoint hard X-ray source.

  Twenty-eight, twenty-nine, thirty. Precisely on that count there came a sudden change. The cloud blew out and away in a fraction of a second. David took a couple of steps forward. It could not be that the Moby had switched itself off—that would not happen for another ten seconds. So it must have reached open water and was falling free through the original and unfrozen center of Blowhole.

  That was bad news. The ice was less thick than they had estimated. If the Moby, working at full power, had encountered the Danae close to the bottom of the ice . . .

  David had set forty seconds as the lower limit of safety, and he was determined to wait that long. Tristan Morgan, sitting inside the Spindrift, lacked such self-control. As soon as the vapor cloud blew away he sent the submersible rolling down the ramp. It hovered for a moment on the edge, tipped crazily, then entered Blowhole with a gigantic splash.

  Tristan was piloting the Spindrift with Hilda Brandt's consent and approval. Nell, sitting at his side, had asked and received no such blessing. She had invited herself and scrambled aboard when everyone else was preoccupied with the Moby's fiery descent into Blowhole.

  This time the soft restraining arms that enclosed her as the ship's tilt angle exceeded tolerance were no surprise. She peered into the turbulent water ahead, trying to see their course as the Spindrift bucked and yawed and rolled in the violent up-currents. Less than a hundred meters below, the Moby was turning ice-cold water into its component elements.

  It did its job. Now if only—for God's sake—it would turn itself—off.

  Nell was recording, but the water around the transparent submersible was a meaningless chaos of blue-lit, bubbling updrafts, as wild as those of any Earth seaquake.

  She turned to Tristan. He lacked Jon Perry's unnatural calm in an emergency. His mouth was gaping, and his eyes started out of his head as he struggled to hold the Spindrift on a st
eady downward course. Above all else, he was trying to avoid the solid wall of Blowhole.

  And failing.

  The ship shivered and creaked as it was thrown against an invisible and unmoving barrier of ice. The hull at Nell's side rang like a bell. Stress indicators all across the control panel flickered to danger levels, and back again. A second collision, moments after the first, wrenched a shrill scream from twisting braces.

  The ship rolled a hundred and twenty degrees. Nell was suddenly hanging facedown and peering into bubbling darkness. She caught a glimpse of a brilliant pinpoint of violet-blue, far beneath.

  "Can't hold it!" But just as Tristan was gasping out those words, the tumult ended. The Spindrift steadied, rolled back to an even keel, and was all at once descending peacefully through a dark, endless chimney.

  Nell stared down through the transparent floor. The ship's lights showed nothing beneath but clear, subsiding water. Beyond their range of visibility, the now-quiescent Moby would be heading down, down, down, toward the remote seafloor. Long before it got there, its internal chambers would collapse under the monstrous pressure. It would be crushed into a compact, useless mass, something for future Europan generations to recover, and perhaps to wonder at.

  Nell and Tristan did not give the vanished Moby another thought. The Spindrift's ultrasonic imager had been turned on, and now its shape-detection programs were raking the dark interior ocean for objects whose external profile matched that of the Danae's.

  The submersible fell and fell, until it was close to the lower edge of the ice blanket. The scanning imager remained silent.

  Tristan angled the descent. "Feels like a waste of time, but Hilda says we gotta do this—or topside will start freezing over again."

  He took the Spindrift across to Blowhole's wall and approached the first of the three heating units attached to the ice face. Two flexible mechanical arms reached forward from their external mooring, moving under Tristan's control.

  Grasping the switch with the submersible's waldoes looked easy, but it seemed to Nell to take forever. She itched to have a go at it herself. Tristan was an experienced pilot in the Jovian atmosphere, but he was unfamiliar with both the Spindrift and the Europan environment.

  And so am I. Less used to them than he is. Nell forced herself to sit back and be quiet. Tristan was doing his best. Distractions and offers of help would only slow him down.

  It took a couple of minutes—hours to Nell, until she checked the clock—to turn on the first heating unit. The other two went more quickly. Tristan grunted in satisfaction as the third unit vibrated into action.

  "At least we're sure of a way back," he said. "Now we can stay down for as long as we like and go as far as we want."

  He had pumped ballast and they were dropping fast, into the quiet dark. But where were they going? Nell peered down. With the whole of Europa's ocean empty beneath them, how would they ever find the speck of a submersible, even with the Spindrift's superior equipment to help them?

  Answer: They wouldn't. Rather than face the reality of Jon and Wilsa's death, she and Tristan had charged off on a pointless search. Millions of cubic miles of ocean would take months to survey. Years.

  Nell, sick at heart, was telling herself to turn off her recorder, to give up hope, when a loud beep came from the ultrasonic imager.

  "Got something," said Tristan. "Moving target. Holding steady."

  Which was more than his voice was doing.

  "Is it them?" asked Nell. Listen to me. I sound like an old frog.

  Tristan did not answer. There was only one other submersible in the Europan ocean. What she was really asking was something quite different: "Are they alive?"

  That question could not be answered with the information from the imager. The Danae appeared to be intact, floating quietly, its power off, about three kilometers below them. It must have been heading back toward Blowhole. But that said nothing about the condition of its passengers.

  Tristan sent a sonic signal to the Danae and they waited breathlessly for a reply. For a word from a human voice—any word.

  There was nothing. Only a fixed message from the onboard computer of the Danae, returning its own status signal: Functioning normally.

  Tristan put the Spindrift into a reckless descent, plunging at the image on the screen until Nell was sure that the two ships would collide. At the last moment he pulled out, to place the submersible directly ahead of the Danae. The Spindrift's free-swimmer lights went straight for the forward window of the other submersible, shining in to illuminate what lay behind it. Nell saw two suited figures, lolling against each other. Their heads were tilted back, their faces invisible.

  "It's them," said Tristan. "They're unconscious."

  Or dead. Nell did not need the other possibility spelled out to her. "How fast can we get them to the surface?"

  "Few minutes. I can get underneath, do a direct lift. It's going to be uncomfortable, though. We'll have to go up flat on our backs and feet-first."

  He was not asking her consent. As the Spindrift dropped, tilted vertically, grabbed, and began the upward run to Blowhole and the surface, Nell was tempted to query the Danae's computer. It could report the internal oxygen and carbon-dioxide levels, information that might tell her if the interior could still support life.

  She reached toward the console . . . and changed her mind. She was no expert on life-support requirements. She would know for sure soon enough.

  Or not soon enough. She stared out of the forward window. They seemed to have been heading upward for ages, but still they were only just at the bottom of the ice shield. She closed her eyes and willed the Spindrift onward with its burden. Faster!

  The upper end of Blowhole's cylinder of liquid water, violently created just a few minutes earlier, was barely wide enough for the unwieldy combination of Danae and Spindrift. Tristan was making things worse by taking the upward run far too fast. Nell felt the shudder and scrape of the submersibles' hulls against ice, and then a bigger and final jolt as the ships rammed through something solid. As the Spindrift crunched its way above the surface and began to push the other ship toward the ramp, Nell understood for the first time the deadly cold of Europa.

  The area where the ships now floated had been subjected to million-degree temperatures no more than half an hour earlier; already it had crusted with a new layer of ice. The heating units, in operation again but over a kilometer below them, were not yet having an effect here.

  Nell had somehow imagined that the group around Blowhole would still be standing there, exactly as she and Tristan had left them. After all, knowing what might be found below the ice, how could anyone bear to tear himself away?

  But the area seemed deserted. The Danae and Spindrift crept steadily along the ramp. Only when the first submersible approached the lumpy Europan surface did Nell realize her mistake. Not far from the end of the ramp—and so large that when she had scanned the area, she had mistaken it for one of the surrounding buildings—the biggest ground car that she had ever seen loomed over the Danae. It was at least thirty meters long and twenty meters across. While she watched, one end slid open. The Danae was grabbed from within and pulled through into a monstrous cargo hold. The end closed. Less than a minute later it opened again.

  "Europan mobile lab," said Tristan as the Spindrift was taken in turn and pulled into the hold. The great door slid closed again, sealing itself. "Particle-flux protected, breathable air once you're past the inner lock. Shirt-sleeve environment. They can get their suits off and put a medical team to work right away. Good thinking by somebody—Hilda, for a bet."

  The Danae had disappeared. Tristan already had his suit halfway off, waiting impatiently for the lock to cycle them through and the outside pressure to equalize. As soon as the Spindrift's hatch could be opened, he jumped out and headed for the inner door.

  Nell followed, a lot more slowly. She was afraid of what she might see on the other side. Only Glyn Sefaris's imagined voice spurred her on; "Do your job
, Nell. You're a reporter. You didn't come all this way to back off now."

  The Danae was sitting in the middle of the next room, hatch open and people swarming over it. Rustum Battachariya sat hunched on a long workbench on the far left. In spite of the biting cold he had ripped open his makeshift suit. Now, like a nightmare parody of an exotic dancer, his black, bulging body was partially visible through folds of billowing and translucent green plastic. Hilda Brandt flanked him on one side, Cyrus Mobarak on the other. Gabriel Shumi stood a couple of paces in front of them. There was no sign of David Lammerman or Camille Hamilton.

  Tristan was struggling to get to the Danae's open hatch. He was held back by three people dressed in the uniform of the Europan general support staff, and they were gently pushing him away from the submersible. Instead of going across to join him, Nell headed for the tall, angular form of Gabriel Shumi.

  "Are they alive, doctor?" That was the only question that mattered.

  Europa's chief medical officer stared right through her and went across to sit on the bench next to Cyrus Mobarak. He put his hands to his head and rubbed his temples until his carefully styled hair was a rumpled mess.

  "I think it is time," he said quietly, "that I retired to Callisto. I own a deep farm there, you know. A big one." Shumi wasn't replying to Nell's question. She realized that he wasn't talking to Mobarak either, or to anyone else on the bench. He was babbling.

  Nell went to stand directly in front of him and placed her face close to his. "How are Jon Perry and Wilsa Sheer? The people in the submersible—are they alive?"

  He glared back at her. "Alive? Why, don't you know you can't kill a visitor to the Europan ocean just by freezing her body solid, or by cutting off his air supply? I'm beginning to wonder if you can do it by chopping somebody to bits. But if you're going to ask me how anyone can possibly be alive, when every rule in the medical book says they must have died over a day ago . . ."He stared mournfully across at the Danae.