He gave the patient sigh of a long-suffering martyr. “Ah, Jeanie. There’s no danger here, the way you’re thinking. I know just what this is.”
“Maybe. But you haven’t told me.”
“I will, though, right now. It’s shadow matter.” And then, seeing my stare, “I’m surprised you’ve not heard of it.”
“I know, Mac. I’m a constant disappointment to you. But I haven’t. So tell me.”
“It’s wonderful. Right out of supersymmetry theory. Soon after the Big Bang—about 10-43 seconds after it, actually, before anything else we know about happened—gravity decoupled from everything else. Sort of like the way that radiation decoupled from matter, but the gravity decoupling happened much earlier. So then you had a symmetry breaking, a sort of splitting, and two types of matter were created: ordinary matter and shadow matter. Just like matter and anti-matter—except that matter and shadow matter can’t interact by strong nuclear forces, or radiation, or the weak nuclear force. They can only interact by gravitational influence. You’d never detect shadow matter by firing particles at it. We proved that for ourselves. The particles feel the gravitational force, but that’s tens of orders of magnitude too weak to do anything noticeable.”
I stared at nothing, in the direction that the mass detectors were pointing. “You’re saying that whatever is out there is as real as we are—but we can’t see it?”
“Can’t see it, never will be able to see it. Seeing depends on interaction with radiation. The only way to learn what we’ve found is through these.” He pointed at the mass detectors. “We’re safe enough, as I said. But we have to do some detailed mapping. Who knows what that is out there? It could be a shadow matter star—we don’t have any idea how big a star might be in that universe, or what the laws of force are. Or maybe we’re detecting a set of interstellar shadow matter spaceships, or a column of shadow matter ants marching in a shadow matter superworld.
“You think I’m joking, but I’m not. It could be anything. The only way we’ll get any idea what we’ve found is by plotting structure. That’s why I need you—it’s a two-person job, to make transects.”
We’re safe enough, he had said. But maybe only while we were outside the Hoatzin.
“Mac, before we start your work we’ve got to talk. I think we have a bad problem.” I told him about the Dummy’s Delight on the ship’s computer.
He frowned through his suit visor. “But why would they waste data storage on a thing like that?”
“So they could get home, even if something happened to both of us.” I took the last mental step, the one I had been resisting. “Mac, we’re not intended to return from this trip. The plan is for us to vanish while we’re out here. If the drive of the ship were turned on now, who’d ever know what had happened to us?”
He turned to stare at the Hoatzin. “They wouldn’t dare.”
“Not now they wouldn’t. I wiped the program they were relying on to fly them back. So they need us.” Or one of us. But I didn’t say that. “We’re safe enough for the moment.”
“But what about when we go back inside? We can’t stay out here forever.”
“I don’t have an answer for you. We’ve got enough air for six or seven hours. We have to think of something—soon.”
We had to think of something. But we didn’t succeed. My mind stayed blank. McAndrew is a superbrain, but not when it comes to this sort of problem. After half an hour floating free not far from the ship, he shook his head.
“It’s got me beat. But this is silly. There’s no point in sitting here doing nothing. We might as well get on with the measurements.”
He placed one mass detector in my care, with its inertial position sensor tuned to the Hoatzin as reference, and started to steer me under his direction from one fixed place to another, while he moved himself in constant relative motion. He apparently knew exactly what he wanted. That was just as well. My own thoughts were all on the situation aboard the ship. What would we do when our air ran low?
I worried that problem with no result while McAndrew made four straight-line passages, right through the middle of the kilometer-wide region that he described as shadow matter. The mass detectors confirmed that something was there. I saw absolutely nothing.
On the fifth passage through, McAndrew paused halfway. He called to me to move closer, while he carried his own detector through a complicated spiral in space. At the end of it he left his mass detector where it was, flew across to me, and examined the recording on my instrument.
“Well, I’m damned,” he said. “Jeanie, I think you were right. Stay there.” And leaving me mystified and feeling about as intelligent as a marker post, he flew away. This time he moved his mass detector through an even more complex path in space, pausing often and proceeding very cautiously.
“I’ve still no idea what this is, overall,” he said when he came back. “But I’ll tell you one thing for sure. There are structures in shadow space that I’ve never met in our spacetime.”
“Right about what?” I asked. “You just said I was right. But what was I right about?”
“That we ought not to set the ship in the middle of that, without knowing more about it. I’m seeing evidence of gravitational line singularities, or something very like them, running across the shadow matter region. You don’t find those in our universe. If we had flown in too close to one of them, we might have found ourselves in trouble.”
“You mean we’re not in trouble now? With Lyle and Parmikan waiting for us.”
“I’ve been thinking about that, too.” He came close, and his face was earnest and unshaven within his visor. “I think you’re overreacting. There’s no evidence at all that Lyle and Parmikan even knew there was a Dummy’s Delight set up in the Hoatzin’s computer. And certainly there’s no evidence they mean us any harm. But anyway,” he went on, before I could interrupt, “one thing’s for sure: When we go back in the lock, I should enter first while you stay outside. I know both of them, they respect me, and they’ll not do anything to hurt me.”
McAndrew is a pathetically bad liar. I didn’t argue with him. But when we were a few meters from the lock I said, “You’ve got it backwards. I’m the one they won’t hurt, because they need a pilot to get home. And you don’t know how to work our only weapon. Don’t stand too near the hatch of the lock.”
I dived for the airlock, pulled myself inside, and swung it closed in one movement, leaving Mac to bang on the outside. While the lock was filling with air I did a little work of my own. It required that three separate safety procedures be overridden, so it took a few minutes. At last I moved forward to open the inner lock door, then jumped back at once to stand by the outer one.
I didn’t know what I was expecting. Lyle and Parmikan, going about the normal business of the ship, with a stack of messy chores ready for me? Or waiting to complain that I had for no reason at all wiped out a program that one of them had set up in the computer, for a wholly innocent purpose?
What I hadn’t expected was a projectile weapon, held in Van Lyle’s hand and pointed right at my belly-button. I rammed my left fist down on the lock control, as the thought flashed through my head that there should have been a more thorough luggage inspection when we boarded the Hoatzin.
I moved as fast as I could, but they had been ready and waiting. I was too slow. Lyle pressed the trigger.
As he did so two things happened. Parmikan smacked at Lyle’s hand and screamed, “Don’t kill her! We need her to get us back.” That saved me, spoiling Lyle’s aim. In the same moment the outer lock door, its final safety trigger broken by the force of my fist, blew outward in a rush of air.
I flew out with it, knowing that my last-ditch plan to fight back had failed. I was hit. And my secret weapon was useless, because Lyle and Parmikan were already wearing suits.
I felt the fainting weakness that comes with a sudden drop of blood pressure. Then my suit resealed, and a few seconds later McAndrew was grabbing at me to halt my spin. He had f
ollowed me as I emerged in that crystal cloud of cooling air.
I felt pain for the first time, and looked down. Half the calf of my left leg was missing. The automatic tourniquet had cut in and tightened below the knee. The flow of blood from the wound had already stopped. I would live—if we somehow survived the next few minutes.
Which didn’t seem likely. Lyle and Parmikan had emerged from the lock, and Lyle still had his gun. He raised it. And shot me again.
Or he would have done, had he been the least bit familiar with freefall kinematics and momentum conservation. Instead the recoil of his gun sent him rolling into a backward somersault, while the bolt itself flew who knows where.
Before Lyle could sort himself out and fire again, McAndrew was dragging me away, using his suit propulsion system at maximum setting to carry both of us along. One nice thing about Mac, he didn’t need much data to form a conclusion.
“Don’t try a long shot.” That was Parmikan to Lyle, over the suit radio. “She’s injured. Get in close. Then we finish him and grab her. But don’t kill her—she’s taking us home.”
“I won’t kill her.” That was Lyle, the white plaster on his nose vivid through the suit’s visor. “Not ’til I’m done with the bitch. She’ll wish she was dead before that.”
They were coming after us, knowing that we had no place to hide. It was our misfortune to find ourselves, weaponless and pursued, in the emptiest quarter of known space. Nowhere to run to, and soon we would be out of air.
McAndrew was retreating anyway, dragging me along with him, but not in a simple, straight-line run. We were zigzagging up and across and sideways, rolling all over the sky; which made good sense if you were trying to evade being shot, and no sense at all when your enemy had just declared that he would not shoot until he got close.
Then we stopped dead. Mac glanced all around him, sighting for Parmikan and Lyle, the two mass detectors just where we had left them, and the shape of the Hoatzin, further off. He lifted us a few meters upward, and halted again.
“Here we are, then,” he muttered. “And here we stay.”
Lyle and Parmikan hadn’t moved while Mac and I had been corkscrewing our way around in space. Now they started towards us. Soon I could see their faces, white in the reflected glow of the visors’ built-in instruments.
Still McAndrew didn’t move. The feeling of distance and unreality that had swamped me the moment I was shot started to fade. At last I was scared. But when I started my propulsion system, ready to take off again away from the advancing men, Mac held out his hand to stop me.
“No, Jeanie. Hold by, and don’t move.”
They were closing on us. Parmikan was two or three meters in the lead. Lyle still held the gun, but he had learned his lesson. He would not fire again until he was at point-blank range, too close to be thrown off in his aim by the effects of free-fall rotation.
“Mac!” We couldn’t stand still and be slaughtered like sheep. I swung to argue with him, and saw the expression on his face. He was agonized and biting his lower lip. “Mac, come on. We can’t just give in.”
But he was shaking his head at me. “I’m sorry, Jeanie,” he said. “This isn’t me. I can’t go through with it. No matter what happens next, I have to give them a chance.” And he lifted his arm towards Lyle and Parmikan. “Don’t come any closer. Stay right there. You are in terrible danger.”
That stopped them—for a second or two. They stared all around, and saw nothing. Lyle snorted through his broken nose, while Parmikan laughed aloud for the first time since I had met him.
“Don’t try that on us, McAndrew,” he said. “We weren’t born yesterday. If you stand still, I promise you’ll get yours clean and quick.”
He was moving forward again. My suit’s vision enhancement showed the grin on his shapeless mouth. He looked as happy as I had ever seen him. And then the clean white of his suit was broken by a thin black line that ran across Stefan Parmikan from hip to hip, about two inches below his navel.
He stared down at himself as the line widened. He started to scream, and tried to back up.
It was too late. His motion carried him forward. As it did so he shrank, shortening and squeezing in towards his hips. The thin black line became a rolling tunnel of red and purple across his whole body. Twisted internal organs were moving into it from above and below. Then Parmikan had passed all the way through.
The scream ended. A pair of legs, still held together at the top, came floating on towards us. Separate from it moved a torso, cleanly severed. Blood gouted out and froze as a fine icy spray.
Lyle, a few meters behind, had enough time to stop. He paused, still holding the gun.
“Hand that over.” I summoned what little energy I had and spoke over the suit radio before McAndrew had time to react. And then, when Lyle hesitated, I said, “Hand it over right now. Or get just the same as he did.”
He hardly seemed to be listening. His eyes were following the horror of Parmikan’s severed body. But he nodded and released the gun, which floated gently away from him.
It’s a measure of how far gone I was that I actually started out towards it, until McAndrew grabbed me.
“You stay where you are, too,” he said. “And Lyle, don’t move a millimeter until we come around and get you. There’s other gravitational line singularities through this whole volume.”
We began to move again, McAndrew hauling me along like ballast in a strange helical path that wound its way towards Van Lyle. Finally McAndrew was able to reach out and snag the gun.
“All right.” He waved it at Lyle, then towards the Hoatzin. “We’ve got a clear run from here to the ship. You start that way. And remember that I understand freefall ballistics a lot better than you do. I won’t miss.”
The three of us drifted slowly back to the lock, but McAndrew would not let Van Lyle enter. He handed me the gun. “You first, Jeanie. Can you fix the lock so it works?”
“I think so.” I moved inside. “I just have to reset the safety interlocks.”
I made it sound trivial, and it should have been. But I kept half blacking-out before I was done and able at last to refill the interior of the Hoatzin with air.
It seemed forever before the lock cycled again. I wondered and stayed tense. I had the gun. Suppose Lyle had taken advantage of that and overpowered McAndrew?
I dropped those worries when Lyle emerged from the inner lock. His manner and bearing were of a crushed man with no fight left in him. I made him take his suit off, but I kept my own on until McAndrew finally came through the lock.
He didn’t give Lyle a look. He came straight across to me and examined my injured leg.
“I’m sorry, Jeanie,” he said, as he helped me ease out of my suit. “I know I put us in danger, warning them the way I did. If Parmikan had stopped in time we might have been killed. But I couldn’t let them go on moving into that line singularity, without giving them at least a chance to stop. I just couldn’t do that. You’d have done the same thing, wouldn’t you?”
“Of course I would.”
Like hell. If it had been up to me, Lyle would be floating around in two halves, the same as Stefan Parmikan. But then, compared with McAndrew I’m a barbaric, vengeful throwback. “Don’t worry about it, Mac. What you did was the right thing.”
I winced, as the suit came free from my calf and caught on crusted blood. “So whose idea was it, Van Lyle?” I said. “Who decided that on this expedition, McAndrew and I wouldn’t be going back?”
He had been sitting slumped over, staring at the floor. He looked up, opened his mouth to speak, then changed his mind. He shook his head.
I didn’t blame him. When we arrived home he would be charged and surely convicted; but nothing the system authorities could do to him was half as bad as Anna Lisa Griss’s vengeance if he betrayed her.
McAndrew had gone across to the capsule’s medical center and was returning with two spray syringes. “I’m going to put you under, Jeanie, while I dress your leg,” h
e said. “You’ll have to wait until we’re home for a full repair. But first, to be safe…”
He went to Van Lyle and pressed the loaded syringe against the back of the stooped man’s neck. Lyle tried to stand up, with a startled expression on his face. It was already too late.
“Better if we keep him under all the way back,” Mac said, as after a few struggling seconds Lyle slid forward and fell face-down on the floor. “That way we don’t have to worry.”
I wasn’t worrying. I was going to be next, and physically I was ready for it. My calf was beginning to throb mercilessly. Still I held up my hand in protest. “Mac, wait a minute. We shouldn’t head back until you’ve finished your experiments. And you’ve hardly started.”
He moved behind me. “Don’t be daft, Jeanie. I can come here anytime. And I surely will. There’s big questions to be answered. I need to map the structure of those shadow matter objects in more detail. And now we’ve got another candidate for the hidden matter. How much is cold dark matter, how much hot dark matter, how much shadow matter?”
The cool nozzle of the syringe touched the back of my neck, and the spray diffused through my skin. I felt the effect at once as a pleasant, relaxing warmth that spread through my whole body.
“Mac,” I said, as the capsule of the Hoatzin began to blur around me. “You saved us, but I don’t know how you did it. How did you know where to go, to put that gravity singularity right between us and those two?”
“Easy enough,” he said. “I had the measurements from the mass detectors. That made it a standard problem of inverse potential theory: Given the field, where are the masses needed to generate it? I already felt sure that there were line singularities of shadow matter, ones that would work—gravitationally—on anything in our universe that encountered them. But just where were they? I worked that out while you were inside the lock, playing your fun and games with Lyle and Parmikan. Of course, I had to make simplifying assumptions and hope they wouldn’t affect the answer. And it would have been really nice to have a computer. But there was no time for that. I did what I could.”
The Compleat McAndrew Page 19