The Heart of the Comet

by David Brin

  The hatch poked free and whoosh—the air inside the slot rushed out, fluttering the straps over his shoulders and his blue coverall.

  He sucked in air through his face mask. Virginia’s risky solution—a small sir bottle, no suit.

  His ears popped, despite the pressure caps he wore over them. Goggles protected his eyes to stop the fluid from sputtering away, freezing his eyelids shut. The straps were so tight they bit into his flesh painfully. That was all he had between him and hard vacuum.

  The slot hatch had stopped at its first secure point, five centimeters clear. Beyond he glimpsed the stark white glare of full sunlight on the rim of the aft port. His sleep slot was pinned to the conveyor, as he had guessed. He saw a few stars, and a shadow moving on the distant smooth curve of the Edmund’s hull. That would be a mech moving on to pop the next slot, to check for gifts bearing Greeks.

  He had gambled that Linbarger would think that was enough precaution. If he was wrong…

  And Linbarger was already hypersuspicious, after they had detected and blocked Virginia’s attempt to take over command of the Edmund’s mechs. Ould-Harrad had insisted on trying that so-called easy solution first, and it had failed quickly. Now for the hard way…

  Linbarger would want the mechs well clear of the Edmund before anyone ventured into the hold to secure the slots. That gave Carl two, maybe three minutes.

  Carl lifted the cover and floated out, curling into a ball as he went. He wore a coverall, gloves, and boots, nothing more.

  How long since the air had vacced? He glanced at his thumbnail. Twenty seconds.

  Saul had figured three minutes of exposure before he would begin to feel the effects. Then his internal pressure imbalance would get serious, he would become woozy, and anybody coming into the bay could handle him like he was a drugged housecat.

  Not that Linbarger and his crowd would waste any time on him. Probably they’d just push him out the lock and wish him bon voyage, like they’d done to poor Kearns. Have a pleasant walk home…

  He uncurled, looked around.

  The hold bay was empty. They were probably watching the mechs separate and back off.

  He repelled off the lock rim and got oriented. The lock’s manual-override seal was a big red handle, deliberately conspicuous, at ten o’clock and across the bay. His ears popped again. His senses were ringing alarms, but he suppressed them all and launched himself across to the red seal-and-flood lever.

  Halfway there, somebody tackled him.

  The suited figure slammed him backward into the bay, grappling for his air hose. Carl twisted away, jerked free.

  Of course. Obvious. Linbarger had put somebody outside, to inspect the mechs as they came in, be sure nobody clung to an underside. From that position the man could see into the hold, too.

  Idiot! Carl chided himself for not predicting this.

  Ninety seconds left.

  They separated, both drifting down the long axis of the hold. It would be ten seconds before either touched a wall. The spacesuited man fumbled for his jets and changed vectors, deftly moving between Carl and the red seal-and-flood.

  Carl had no doubt that the fellow could stop him from reaching the lever for a minute or so. The Ortho had jets, air, and all the time in the world.

  Dame, it’s cold, too. Carl twisted, looking for something, anything.

  There. A set of tools. He glided by the berth rack stretched—and snatched up an autowrench. Carefully he aimed at the figure ten meters away and threw.

  It missed by a good meter. Carl could see the man’s face split into a sardonic grin, the lips moving, describing it all with obvious delight for the Edmund’s bridge.

  Which was what Carl wanted. Throwing the heavy wrench had given him a new vector. He coasted across the bay, windmilled, carne about to absorb the impact with his legs.

  Where was the damned—?

  He sprang for it. The fire extinguisher easily jerked free of its clasp. Carl pointed the nozzle at his feet and fired. A pearly white cloud billowed under him and he shot back across the bay, still no closer to the seal-and-flood.

  His ears popped again. Purple flecks brushed at his eyes, making firefly patterns …

  He struck the opposite wall, this time unprepared. A handle jabbed him in the ribs.

  Where was… ? He launched himself at the man, riding a foam jet. Halfway there he cat-twisted, bringing the fire-extinguisher nozzle to bear ahead of him—and slammed it on full.

  Action and reaction. He slowed, stopped—and the frothing white cloud enveloped him. He fired again and rushed backward, out of the thinning smoke.

  Darkening purple everywhere. The raw light of the berth lamps couldn’t seem to cut through it …

  Now, before the roiling fog cleared, he flipped again and fired one more time. He flew through blank whiteness—and struck something soft, yielding.

  He grabbed at the man with one arm, bringing around the extinguisher. Hands snatched at him, clawed at his face mask.

  Vectors, vectors…

  Which way… ?

  It didn’t matter. He pressed the nozzle against the man and pulsed it again.

  Billowing gray gas.

  Cold, so cold…

  … A huge hand pushing him backward…

  A long second of gliding… the extinguisher slipped away… numb hands… he was tumbling… aching cold in his legs… impossible to see…the purple getting darker…shot through with bee-swarm white flecks darting in and out…in and out…spinning…

  —then a jolting stab of pain in his leg, crack as his skull hit decking.

  It jarred him back to alertness. He clawed for a hold. Looked up.

  The fog was thinning. Directly out through the lock Carl could see the suited figure wriggling, dwindling, trying to get reoriented to use his jets. An insect, silvery and graceful…

  The thrust of the last pulse had acted equally efficiently on each of them, driving Carl inward and the other man out.

  He sprang for the seal-and-flood. Grasped it, pulled. The lock slid shut just before his opponent reached it, and the loud roaring hiss of high-pressure air sounded for all the world like a blaring, rude cry of celebration.

  “I made it,” Carl said into his comm. “The tubes are blocked.” He panted in the close, oily air of the pressurized cylinder.

  “Good!” Ould-Harrad answered in his ears. Now there was no indecisiveness, no fatalism in the voice. “Linbarger, hear that?”

  “What’s that jackass mouthing about?” carne the chief mutineer’s sneer.

  “Carl Osborn has jammed up the fusion feed lines,” Ould-Harrad said precisely.

  Faintly the voice of Helga Steppins: “Fuck! I told you to cover the fore tubes!”

  Even fainter: “He must’ve crawled through them from Three F section. Shit, we can’t cover every little.”

  “Shut up.” Linbarger’s voice got louder as he addressed Ould-Harrad. “We’ll sweat him out of there.”

  “You try it and I’ll vent the tritium,” Carl said tensely.

  “What?” Linbarger could barely contain his anger. He demanded of some unseen lieutenant, “Can he do that?”

  Faintly: “I don’t… Yeah, if he opened those pressure lines into the core storage. He might’ve had time to do that.”

  “Without tritium to burn, your fusion pit won’t reach trigger temperature,” Carl added helpfully, grinning.

  “You—!” Linbarger’s line went dead.

  Carl twisted and made sure the entrance behind him had a hefty tool cabinet jamming the way. He had long-lever wrenches on the two crucial pressure points, ready to crack open the valves. They could come at him from behind, but he could spray a lot of precious fuel out into space before they got the valves closed again. Enough to kill their plans, certainly.

  “Are you sure you can do it, Osborn?” Ould-Harrad asked cautiously.

  “Yeah.” What do you want me to say? No? With Linbarger listening ?

  “Well, this certainly gives u
s a better bargaining position…

  “Bargain, hell! We’ve got ’em by the balls.”

  “If they get to you fast enough, perhaps they can retain enough tritium to make a multiple flyby with Mars. Draw lots to use the nine slots they have now. Then.”

  “Cut that crap.” Go ahead, give them ideas.

  “I’m simply.”

  “I said cut it!”

  “I’m trying to prevent.”

  “It’s not your ass on the line over here, Ould-Harrad.”

  He twisted, watching the feeder lines drop away to the left. If somebody wriggled in that way, they might try to shoot at him. But that would be stupid, right in the middle of the fusion core. Damage these fittings and they would take weeks to replace, if ever.

  Linbarger’s grim voice said, “You hear me on this hookup, Osborn?”

  “I’m right here, just a friendly hundred meters away.”

  Silence. Then Linbarger’s reedy, tight voice said slowly, “We’ll fire the start-up pinch if you don’t leave.”

  Carl caught his breath, let it out slowly. That was the one alternative he hadn’t mentioned to anybody. It wasn’t smart, because start-up could do real damage if you handled it wrong—and Linbarger had no experience at that. But he had seen the possibility of frying Carl as the hot fluids squirted through this network of tubes. And Linbarger was just desperate enough to do it.

  He said as calmly as he could, “You’ll burn out the throat.”

  “Not if we’re careful. It won’t take too much fusion fire to cook you up to a nice, brown glaze.” Linbarger was clearly enjoying himself, thinking he had turned the tables.

  “I’ll vent the tritium anyway.” Now let’s see how much he knows.

  “No, you won’t. The subsystems will shut down those lines as soon as we start up. It’s automatic—says so right in the blueprints.”

  Damn. “That’s not the way it’ll work.” Bluff.

  “Don’t try that crap on me.”

  Linbarger was smarter than Carl had thought. But he wasn’t going to win.

  “You’ll never get back Earthside. You’re low on tritium as it is. I’ll blow enough of it to make sure you have a long voyage. You’ll never pick up the delta-V for a Jupiter carom. Even with the sleep slots, you’ll starve.”

  “We’ve got the hydroponics.”

  “Sure. And no extra water to run it.”

  “There’s Halley ice right outside.”

  “Try stepping outside.” Carl played a hunch “Hey—Jeffers! What happened to that Arcist I blew out the lock?”

  —What Arcist? All I see is bits ’n pieces.—

  Silence.

  This tit-for-tat couldn’t go on much longer. Linbarger’s voice was getting thin, hollow-sounding. The man’s words came too fast, spurting out under pressure.

  Carl bunched his jaw muscles, wondering if he believed his own words. If Linbarger acted, it would be a matter of seconds. Carl would have to choose whether to launch himself for the aft hatch and try to get away, or to use the wrenches. No time for dithering…

  “You’re lying.” Linbarger didn’t sound so certain now.

  “Fuck you.”

  “You wouldn’t.”

  “I’m starting tritium release now.”

  “No!” Ould-Harrad said. “I won’t have it come to this. We had a deal worked out.”

  “And you double-crossed us! Percell-lover!” Linbarger barked.

  Ould-Harrad said, “I couldn’t let that hydroponics equipment go, you refused to understand that.”

  Carl said caustically, “Don’t apologize to that scum.”

  “Carl,” Ould-Harrad said, “I must ask you to stop.”

  “The party’s over,” Carl said. “Surrender, Linbarger!”

  “I think I’ll give you a little pulse of the hot stuff, Osborn. It might improve your manners.”

  “The second I hear a gurgle through these pipes, you Arcist prick, I’ll.”

  “Stop it! Both of you! We have to work this out.” The African’s voice was frantic.

  A long silence. Carl tried to imagine what was going through Linbarger’s mind. The man had apparently concealed from the Psych Board his fanatical hatred of Percells. Or maybe he’d just snapped. Could he think around that now, be halfway rational?

  They’ve lost, dammit. Could Linbarger see that? Or would he prefer his moment of revenge?

  And Carl would know of it by a whispering in the pipes…

  “Okay.” Linbarger’s voice was grating, sour.

  Ould-Harrad answered, “What? You agree?”

  “We’ll trade the hydro for the tritium and slots.”

  “No!” Carl cried. “We have them!”

  “Quiet, Osborn!” Ould-Harrad shouted.

  “The alternative,” Linbarger said slowly, “is that I blow up the Edmund Halley. Better… all of us here agree… better a quick end… than…”

  Carl felt a cold chill at the croaking, slurred, mad voice. It was utterly convincing. He really means it. “Sweet Jesus,” Carl muttered.

  First his captain, dead. Now the Edmund.

  Ould-Harrad spoke at last. “We… we will make the exchange.”

  What is a spacer without a spaceship? Carl wondered numbly. What will we be, when the Edmund is gone? It was too awful to even think of.

  “You can offload the hydro stuff,” Linbarger said. “Get Osborn out of there and I’ll set the mechs to doing it.”

  “No. I stay here until it’s done.”

  Another silence. “Well…” More whispered arguing. Finally, “Okay. You can use those mechs to detach the main greenhouse module as a unit. Make it fast—or we’ll fry that piece of Percell shit.”

  Carl let out a long, slow breath. The thought he had suppressed all these long minutes, that kept jabbing him, finally came swarming up: Why are you doing this? You could die, fool.

  Now that he let it surface, he had no answer.

  “Hurry up,” he said irritably.

  SAUL

  April 2062

  Wriggling, fluttering in a saline solution, the tiny bests flicked here and there, hunting, always hunting.

  Certain substances, flavors, drew them to the equivalent of sweetness. Others repelled. The choice was always as easy as that, a logic of trophic chemistry. On the level of the cell, there were no subtleties, no future to worry about. No past to haunt one’s dreams.

  Saul was pensive as he watched the tiny creatures pulse under the fiber microscope. They were the last and most potent of the new developments cooked up during the two months since the mutiny. Biological smart bombs for an unwanted war against Comet Halley.

  So many of the rules he had lived by—codes of slow caution when experimenting with the stuff of life—had been pushed aside in order to get here. He envied the little microbes, in a way. For they would do as they were programmed, but he, their “creator,” was left with his load of doubt and mystery.

  No. Of course you don’t worry, little ones. Guilt is a teamwork thing—a trait of eucaryotic metazoans—vast collections of conspiring cells gathered to form men and women, societies… gods.

  Look at me, tampering with what I barely understand, on the questionable excuse that all our human lives depend on it.

  The cyanutes had fully as much history behind them as he did. Their tiny ancestors had spent well over three billion years evolving in Earth’s waters. Then, some few millions of years ago, they adapted to take up a different way of life in another salty soup—the bodily fluids of complex creatures with great, nucleated cells.

  How many thousands of my own ancestors did they kill in order to establish that first beachhead? How many trillions of them, in turn, were fought off by my forebears’ immune systems—latched onto by antibodies and transported to destruction, or engulfed and digested by white cells? How long did it take for a truce to be called at last… for evolution to work out a negotiated peace, a symbiosis ?

  It was an unanswerable question. But at some point
in the past some human being and some ancestral cyanute struck an accidental bargain. In exchange for a minor cleansing function in the lung cavity, the creatures were granted safe conduct from the body’s immune system. They settled down to an innocuous existence, so innocuous, in fact, that they weren’t even discovered until the waning days of the last century.

  In our wisdom, we meddled with them, turning them into “cyanutes.” And, Heaven forgive me, I’m not ashamed at all. A hundred skilled, devoted men and women spent half a decade altering the fruits of four gigayears’ evolution. Given special permission, we used the tools of Simon Percell—and forged a useful thing of beauty.

  But this!

  The creatures on the screen had been changed even more, given jagged new protein coats, snipped and edited with tailored chain molecules, analyzed and reanalyzed by “reader enzymes”… warped by the drives of an emergency nobody had expected.

  The job had taken only eight weeks since the mutiny. And, except for Virginia and her biocybernetic familiar, and a few tentative suggestions from brave colleagues on Earth, he had had no help at all.

  By all the laws of biology I should not have succeeded. Not without a research team and thousands of hours of careful simulation. Millions of tests. Heaps of luck.

  I knew better!

  It‘s a wonder that I even tried.

  Saul’s eyes flicked over the unrolling data display, seeing nothing but success. The uniformity of it made him more nervous than any flaw. It was too perfect.

  I took both the sample cyanutes and the reader units from my own blood. The data on that line goes back more than five years.

  There are elements of Halley-Life in the new form… I had to include them.

  Saul shook his head. He couldn’t see how that would explain this convenient success.

  To the left, one of JonVon’s unbiquitous color simulations turned a complex, jagged chain over and over.

  The involute compound sugar was unknown in the literature. Last night, while holding Virginia close, he had told her that the Academy on Earth wanted to name it after him.

  “That’s quite an honor, isn’t it?” she had asked sleepily. The cable snaking out from her neural tap looked like a braid of hair, and hardly got in the way.