Vectors

by Charles Sheffield

  "But couldn't we use smaller kernels on Earth?" asked Yifter. "They would be less dangerous."

  McAndrew shook his head. "It doesn't work that way. The smaller the black hole, the higher the effective temperature and the faster it radiates. You'd be better off with a much more massive black hole. But then you've got the problem of supporting it against Earth's gravity. Even with the best electromagnetic control, anything that massive would sink down into the Earth."

  "I suppose it wouldn't help to use a non-rotating, uncharged hole, either," said Yifter. "That might be easier to work with."

  "A Schwartzschild hole?" McAndrew looked at him in disgust. "Now, Mr. Yifter, you know better than that." He grew eloquent. "A Schwartzschild hole gives you no control at all. You can't get a hold of it electromagnetically. It just sits there, spewing out energy all over the spectrum, and there's nothing you can do to change it—unless you want to charge it and spin it up, and make it into a kernel. With the kernels, now, you have control."

  I tried to interrupt, but McAndrew was just getting warmed up. "A Schwartzschild hole is like a naked flame," he went on. "A caveman's device. A kernel is refined, it's controllable. You can spin it up and store energy, or you can use the ergosphere to pull energy out and spin it down. You can use the charge on it to move it about as you want. It's a real working instrument—not a bit of crudity from the Dark Ages."

  I shook my head, and sighed in simulated despair. "McAndrew, you have an unconsummated love affair with those blasted kernels." I turned to Yifter and Bryson, who had watched McAndrew's outburst with some surprise. "He spends all his waking hours spinning those things up and down. All the last trip, he was working the kernels in gravitational focusing experiments. You know, using the fact that a gravity field bends light rays. He insists that one day we won't use lenses for optics—we'll focus light using arrays of kernels."

  I made the old joke. "We hardly saw him on that trip. We were convinced that one day he'd get careless with the shields, fall into one of the kernels, and really make a spectacle of himself."

  They didn't get it. Yifter and Bryson looked at me blankly, while McAndrew, who'd heard it all ten times before, chuckled. We have the same sense of humor—a bad joke is always funny, even if it's the hundredth time you've heard it told.

  It's a strange thing, but after the first half-hour I had stopped thinking of Yifter as our prisoner. I could understand now why Bryson had objected to the idea of surrounding Yifter with armed guards. I'd have objected myself. He seemed the most civilized man in the group, with a warm personality and a very dry and subtle sense of humor.

  When Bryson left the table, pleading a long day and a lack of familiarity with a space environment, Yifter, McAndrew and I stayed on, chatting about the previous trips I had made to Titan. I mentioned the time I had taken the circus.

  "Do you know, I'd never seen most of those animals before," I said. "They were all on the list of endangered species. I don't think you could find them on Earth any more, except in a circus or a zoo."

  There was a moment of silence, then Yifter spoke. His eyes were mild and smiling, and his voice sounded dreamy and distant.

  "Endangered species," he said. "That's the heart of it. Earth has no room for failures. The weaker species, like weaker specimens of a species, must be eliminated. Only the strong—the mentally strong—may survive. The weak must be culled, for our own sake; whether that means one tenth, one half, or nine tenths of the total."

  There was a chilling pause. I looked at Yifter, whose expression had not changed, then at McAndrew, whose face reflected the horror that I was feeling. Yet behind all that, I could feel the unique power of the man. My mind was rejecting him, but I still had a sense of well-being, of warmth in the pit of my stomach, as he was speaking.

  "We have made a beginning," went on Yifter quietly. "Just a beginning. Last time we were less successful than I had hoped. We had a breakdown in the distribution system for the drugs. I managed to eliminate the responsible individuals, but it was too late to correct the problem. Next time, God willing, it will be different."

  He rose to his feet, white hair shining like silver, face beatific. "Good night, Captain. Good night, Professor McAndrew. Sleep well."

  After he had left, McAndrew and I sat and looked at each other for a long time. Finally, he broke the spell.

  "Now we know, Captain. We should have guessed it from the beginning. Mad as a hatter. The man's a raving lunatic. Completely psychotic."

  That said most of it. McAndrew had used up all the good phrases. I nodded.

  "But did you feel the strength in him?" went on McAndrew. "Like a big magnet."

  I was glad that the penal colony was so far from Earth, and the avenues of communication so well-guarded. "Next time . . . it will be different." Our two-month trip suddenly seemed to have doubled in length.

  * * *

  After that single, chilling moment, there were no more shocks for some time. Our regular meal-time conversations continued, and on several occasions McAndrew voiced views on pacifism and the protection of human life. Each time, I waited for Yifter's reply, expecting the worst. He never actually agreed with Mac—but he did not come out with any statement that resembled his comments of the first ship-evening.

  We soon settled into the ship-board routine. McAndrew spent less and less time in the Control Stage, and more in Section Seven. On this trip, he brought a new set of equipment for his experiments, and I was very curious to know what he was up to. He wouldn't tell. I had only one clue. Section Seven was drawing enormous energy from the other kernels, in the rest of the Assembly. That energy could only be going to one place—into the kernel in Section Seven. I suspected that McAndrew must be spinning it up—making it closer to an "extreme" kernel, a Kerr-Newman black hole where the rotation energy matches the mass energy. I knew that couldn't be the whole story. McAndrew had spun up the kernels before, and he had told me that there was no direct way of getting a really extreme kernel—that would take an infinite amount of energy. This time, he was doing something different. He insisted that Section Seven had to be off-limits to everybody.

  I couldn't get him to talk about it. There would be a couple of seconds of silence from him, then he would stand there, cracking his finger joints as though he was snapping out a coded message to me. He could be a real sphinx when he chose.

  Two weeks from Earth, we were drawing clear of the main Asteroid Belt. I had just about concluded that my worries for the trip were over, when the radar reported another ship, closing slowly with us from astern. Its spectral signature identified it as the Lesotho, a cruise liner that usually ran trajectories in the Inner System. It was broadcasting a Mayday, and flying free under zero drive power.

  I thought about it for a moment, then posted Emergency Stations throughout the Assembly. The computed trajectory showed that we would match velocities at a separation of three kilometers. That was incredibly close, far too close to be accidental. After closest approach, we would pull away again—we were still under power, accelerating outward, and would leave the Lesotho behind.

  I was still watching the displays, trying to decide whether or not to take the next step—shutting off the drives—when Bryson appeared, with Yifter just behind him.

  "Captain Roker," he said, in his usual imperious manner. "That's an Earth ship there, giving you a distress signal. Why aren't you doing anything about it?"

  "If we waited just a few minutes," I said. "We'll be within spitting distance of her. I see no point in rushing in, until we've had a good look at her. I can't think what an Inner System ship would be doing, free-falling out here beyond the Belt."

  That didn't cool him. "Can't you recognize an emergency when you see one?" he said. "If you won't do something productive with your people, I'll do something with mine."

  I wondered what he wanted me to do, but he walked away from me without saying anything more, down the stairs that led to the rear communication area of the Control Stage. I turned back to t
he displays. The Lesotho was closing on us steadily, and now I could see that her locks were open. I cut our propulsion to zero and switched off all the drives. The other ship was tumbling slowly, drive lifeless and aft nacelles crumpled. Even from this distance, I could see that she would need extensive repairs before she could function again.

  I was beginning to think that I had been overcautious when two things happened. Yifter's guards, who had been housed behind the Control Stage in Section Two, began to float into view on the viewing screen that pointed towards the Lesotho. They were all in space armor and heavily weaponed. At the same time two suited figures appeared in the open forward lock of the other vessel. I cut in the suit frequencies on our main board.

  "—shield failure," said the receiver. "Twenty-seven survivors, and bad injuries. We must have painkillers, medical help, water, food, oxygen and powerpacks."

  With that, one group of our guards outside began to move towards the two suited figures in the Lesotho's lock, while the remainder stayed close to the Assembly, looking across at the other ship. Subconsciously, I noted the number of our guards in each party, then gave them my full attention and did a rapid re-count. Twenty-five. All our guards. I swore and cut in the transmitter.

  "Sergeant, get half of those men back inside the Assembly shields. This is Captain Roker. I'm overriding any other orders you may have received. Get the nearer party—"

  I was interrupted. The display screen flashed blue-white, then over-loaded. The whole Control Stage rang like a great bell, as something slapped hard on the outer shield. I knew what it was: a huge pulse of hard radiation and highly energetic particles, smashing into us in a fraction of a microsecond.

  Yifter had been floating within a couple of meters of me, watching the screens. He put his hand to the wall to orient himself as the Control Stage vibrated violently. "What was that?"

  "Thermonuclear explosion," I said shortly. "Hundred megaton plus. On the Lesotho."

  All the screens on that side were dead. I activated the standby system. The Lesotho had vanished. The guards had vanished with it, vaporized instantly. All the cables linking the parts of the Assembly, all the scanners and sensors that were not protected behind the shields, were gone. The Sections themselves were intact, but their coupling fields would have to be completely recalibrated. We wouldn't be arriving at Titan on schedule.

  I looked again at Yifter. His face was now calm and thoughtful. He seemed to be waiting, listening expectantly. For what? If the Lesotho had been a suicide mission, manned by volunteers who sought revenge on Yifter, they hadn't had a chance. They couldn't destroy the Assembly, or get at Yifter. If revenge were not the purpose, what was the purpose?

  I ran through in my mind the events of the past hour. With the drives switched off in the Assembly, we had an unprotected blind spot, dead astern. We had been putting all our attention on the Lesotho. Now, with the guards all dead, the Control Stage was undefended.

  It was quicker to go aft and take a look, than to call Bryson or McAndrew and ask them what they could see from the rear viewing screens of the Control Stage. Leaving Yifter, I dived head-first down the stairway—a risky maneuver if there were any chance that the drive might come back on, but I was sure it couldn't.

  It took me about thirty seconds to travel the length of the Control Stage. By the time that I was half-way, I knew I had been thinking much too slowly. I heard the clang of a lock, a shout, and the sputtering crackle of a hand laser against solid metal. When I got to the rear compartment, it was all finished. Bryson, pale and open-mouthed, was floating against one wall. He seemed unhurt. McAndrew had fared less well. He was ten meters further along, curled into a fetal ball. Floating near him I saw a family of four stubby pink worms with red-brown heads, still unclenching with muscle spasm. I could also see the deep burn on his side and chest, and his right hand, from which a laser had neatly clipped the fingers and cauterized the wound instantly as it did so. At the far end of the room, braced against the wall, were five suited figures, all well-armed.

  Heroics would serve no purpose. I spread my arms wide to show that I was not carrying a weapon, and one of the newcomers pushed off from the wall and floated past me, heading towards the front of the Control Stage. I moved over to McAndrew and inspected his wounds. They looked bad, but not fatal. Fortunately, laser wounds are very clean. I could see that we would have problems with his lung unless we treated him quickly. A lobe had been penetrated, and his breathing was slowly breaking the seal of crisped tissue that the laser had made. Blood was beginning to well through and stain his clothing.

  McAndrew's forehead was beaded with sweat. As the shock of his wound wore off, the pain was beginning. I pointed to the medical belt of one of the invaders, who nodded and tossed an ampoule across to me. I injected McAndrew intravenously at the big vein inside his right elbow.

  The figure who had pushed past me was returning, followed by Yifter. The face plate of the suit was now open, revealing a dark-haired woman in her early thirties. She looked casually at the scene, nodded at last, and turned back to Yifter.

  "Everything's under control here," she said. "But we'll have to take a Section from the Assembly. The ship we were following in caught some of the blast from the Lesotho, and it's no good for powered flight now."

  Yifter shook his head reprovingly. "Impatient as usual, Akhtar. I'll bet you were just too eager to get here. You must learn patience if you are to be of maximum value to us, my dear. Where did you leave the main group?"

  "A few hours' drive inward from here. We have waited for your rescue, before making any plans for the next phase."

  Yifter, calm as ever, nodded approvingly. "The right decision. We can take a Section without difficulty. Most of them contain their own drives, but some are less effective than others."

  He turned to me, smiling gently. "Captain Roker, which Section is the best equipped to carry us away from the Assembly? As you see, it is time for us to leave you and rejoin our colleagues."

  His calm was worse than any number of threats. I floated next to McAndrew, trying to think of some way that we could delay or impede the Lucies' escape. It might take days for a rescue party to reach us. In that time, Yifter and his followers could be anywhere.

  I hesitated. Yifter waited. "Come now," he said at last. "I'm sure you are as eager as I am to avoid any further annoyance"—he moved his hand, just a little, to indicate McAndrew and Bryson—"for your friends."

  I shrugged. All the Sections contained emergency life-support systems, more than enough for a trip of a few hours. Section Two, where the guards had been housed, lacked a full, independent drive unit, but it was still capable of propulsion. I thought it might slow their escape enough for us somehow to track it.

  "Section Two should be adequate," I said. "It housed your guards in comfort. Those poor devils certainly have no need for it now."

  I paused. Beside me, McAndrew was painfully straightening from his contorted position. The drugs were beginning to work. He coughed, and red globules floated away across the room. That lung needed attention.

  "No," he said faintly. "Not Two, Yifter. Seven. Section Seven."

  He paused and coughed again, while I looked at him in surprise.

  "Seven," he said at last. He looked at me. "No killing, Captain. No—Killing vector."

  The woman was listening closely. She regarded both of us suspiciously. "What was that all about?"

  My mouth was gaping open as wide as Bryson's. I had caught an idea of what McAndrew was trying to tell me, but I didn't want to say it. Fortunately, I was helped out by Yifter himself.

  "No killing," he said. "My dear, you have to understand that Professor McAndrew is a devoted pacifist—and carrying his principles through admirably. He doesn't want to see any further killing. I think I can agree with that—for the present."

  He looked at me and shook his head. "I won't inquire what dangers and drawbacks Section Two might contain, Captain—though I do seem to recall that it lacks a decent drive un
it. I think we'll follow the Professor's advice and take Section Seven. Akhtar is a very competent engineer, and I'm sure she'll have no trouble coupling the drive to the kernel."

  He looked at us with a strange expression. If it didn't sound so peculiar, I'd describe it as wistful. "I shall miss our conversations," he said. "But I must say goodbye now. I hope that Professor McAndrew will recover. He is one of the strong—unless he allows himself to be killed by his unfortunate pacifist fancies. We may not meet again, but I am sure that you will be hearing about us in the next few months."

  They left. McAndrew, Bryson and I watched the screens in silence, as the Lucies made their way over to Section Seven and entered it. Once they were inside, I went over to McAndrew and took him by the left arm.

  "Come on," I said. "We have to get a patch on that lung."

  He shook his head weakly. "Not yet. It can wait a few minutes. After that, it might not be necessary."

  His forehead was beading with sweat again—and this time it was not from pain. I felt my own tension mounting steadily. We stayed by the display screen, and as the seconds ticked away my own forehead began to film with perspiration. We did not speak. I had one question, but I was terribly afraid of the answer I might get. I think that Bryson spoke to both of us several times. I have no idea what he said.

  Finally, a pale nimbus grew at the rear of the Section Seven drive unit.

  "Now," said McAndrew. "He's going to tap the kernel."

  I stopped breathing. There was a pause of a few seconds, stretching to infinity, then the image on the screen rippled slightly. Suddenly, we could see stars shining through that area. Section Seven was gone, vanished, with no sign that it had ever existed.

  McAndrew took in a long, pained breath, wincing as his injured lung expanded. Somehow, he managed a little smile.