Hidden Variables (15 page)

"Never mind that. Give me the library access codes, and let me get at the input console. I want to see if Mac's path shows intersection with any of the high-density objects out here."

Wenig looked skeptical. "The chances of such a close encounter are very small. One in millions or billions."

I was already calling up the access sequence. "By accident? I'd agree with you. But McAndrew must have had some reason to fly back through the System, and make the slight course change that you recorded. I think he was telling us where he was going. And the only place he could have been going between here and Sirius would be one of the collapsed bodies out in the Halo."

"But why?" Wenig was standing at my shoulder, fingers twitching.

"Don't know that." I stood up. "Here, you do it, you must have had plenty of experience with
Dotterel
's computer. Set it for anything that would put
Merganser
within five million kilometers of a high-density body. That's as close as I think we can rely on trajectory intersection."

Wenig's fingers were flying over the keys—he should have been a concert pianist. I've never seen anybody handle a programming sequence at that rate. While he was doing it the com-link whistled for attention. I turned to it, leaving Wenig calling out displays and index files.

"It's Limperis," I said. "Problems. President Velez is starting to breathe down his neck. Wants to know what has happened to Nina. When will she be back? Why did Limperis and the rest of you let her go on a test trip? How can the Institute be so irresponsible?"

"We expected that." Wenig didn't look up. "Velez is just blowing off steam. There's no way that any other ship could get out here to us in less than three months. Does he have anything useful to suggest?"

"No. He's threatening Limperis with punitive measures against the Institute. Says he'll want a review of the whole organization."

"Limperis is asking for our reply?"

"Yes."

Wenig keyed in a final sequence of commands and sat back in his seat. "Tell him Velez should go fuck himself. We've got enough to do without interference."

I was still reading the incoming signals from Triton Station. "I think Dr. Limperis has already sent that message to the President's Office, in not quite those words. We'd better get Nina back safely."

"I know that." Wenig hit a couple of keys and an output stream began to fill the scope. "Here it comes. Closest approach distances for every body within five hundred AU, assuming McAndrew held the same course and acceleration all the way out. I've set it to stop if we get anything better than a million kilometers, and display everything that's five million or closer."

Before I could learn how to read the display, Wenig banged both hands down on the desk and leaned forward,

"Look at that!" His voice showed his surprise and excitement. "See it? That's HC-183. It's 322 AU from the Sun, and almost dead ahead of us. The computer shows a fly-by distance for
Merganser
too small to compute—that's an underflow where we ought to see a distance."

"Suppose that McAndrew decelerated as he got nearer to it?"

"Wouldn't make much difference, he'd still be close to rendezvous—speeds in orbit are small that far out. But why would he want to rendezvous with HC-183?"

I couldn't answer that, but maybe we were at least going to find
Merganser
. Even if it was only a vaporized trace on the surface of HC-183, where the ship hit it.

"Let's get back with our drive," I said. "What's the mass of HC-183?"

"Pretty high." Wenig frowned at the display. "We show a five thousand kilometer diameter and a mass that's half of Jupiter's. Must be a good lump of collapsed matter at the center of it. How close do you want to take us? And what acceleration for the drive?"

"Give us a trajectory that lets us take a close look from bound orbit. A million kilometers ought to be enough. And keep us down to twenty gee or better. I'll send a message back to the Institute. If they have any more information on HC-183, we want it."

* * *

Wenig had been impatient before, when we weren't going anywhere in particular. Now that we had a target he couldn't sit still. He was all over our three-meter living-capsule, fiddling with the scopes, the computer, and the control console. He kept looking wistfully at the drive setting, then at me.

I wasn't having any. I felt as impatient as he did, but when we had come this far I didn't want to find we'd duplicated
all
McAndrew's actions, including the one that might have been fatal. We smoothly turned after twenty-two hours, so our drive began to decelerate us, and waited out the interminable delay as we crept closer to the dark mass of HC-183. We couldn't see a sign of it on any of the sensors, but we knew it had to be there, hidden behind the plasma ball of the drive.

When our drive went off and we were in orbit around the black mass of the hidden proto-planet, Wenig was at the display console for visible wavelengths.

"I can see it," he shouted.

My first feeling of relief and excitement lasted only a split second. There was no way we would be able to spot the
Merganser
from a million kilometers out.

"What are you seeing? Infrared emission from HC-183?"

"No, you noodle. I can see the ship—McAndrew's ship."

"You can't be. We'd have to be right next to it to be able to pick it up with our magnifications." I spun my seat around and looked at the screen.

Wenig was laughing, hysterical with relief. "Don't you understand? I'm seeing the
drive
, not
Merganser
itself. Look at it, isn't it beautiful?"

He was right. I felt as though I was losing my reason. McAndrew might have gone into orbit about the body, or if he were unlucky he might have run into it—but it made no sense that he'd be sitting here with the drive on. And from the look of the long tail of glowing plasma that stretched across twenty degrees of the screen, that drive was on a high setting.

"Give me a Doppler read-out," I said. "Let's find out what sort of orbit he's in. Damn it, what's he doing there, sight-seeing?"

Now that it looked as though we had found them, I was irrationally angry with McAndrew. He had brought us haring out beyond the limits of the System, and he was sitting there waiting when we arrived. Waiting, and that was all.

Wenig had called up a display and was sitting there staring at it in perplexity. "No motion relative to HC-183," he said. "He's not in an orbit around it, he's got the ship just hanging there, with the drive balancing the gravitational attraction. Want me to take us alongside, so we can use a radar signal? That's the only way he'll hear us through the drive interference."

"I guess we'll have to. Take us up close to them." I stared at the screen, random thoughts spinning around my head. "No, wait a minute. Damn it, once we set up the computer to take us in there, it will do automatic drive control. Before we go in, let's find out what we're in for. Can you estimate the strength of HC-183's gravitational attraction at the distance that
Merganser
is at? Got enough data for it?"

"Give me a second." Wenig's fingers flew over the console again. If he ever decided that he didn't want to work at the Penrose Institute, he'd make the best space-racer in the System.

He looked at the output for a second, frowned, and said, "I think I must have made an error."

"Why?"

"I'm coming up with a distance from the surface of about nine thousand kilometers. That means the
Merganser
would be feeling a pull of fifty gee—their drive would be full on, as high as it's designed to go. It wouldn't make sense for them to hang there like that, on full drive. Want to go on down to them?"

"No. Hold it where we are." I leaned back and closed my eyes. "There has to be a pattern to what Mac's been doing. He went right through the System back there with the drive full on, now he's hanging close in to a high-density object with the drive still full on. What the hell's he up to?"

"You won't find out unless we can get in touch with him." Wenig was sounding impatient again. "I say we should go on down there. Now we know where he is it's easiest to just go and ask him."

It was hard to argue with him, but I couldn't get an uneasy feeling out of the back of my head. Mac was holding a constant position, fifty gee of thrust balancing the fifty gee pull of HC-183. We couldn't get alongside him unless we were willing to increase
Dotterel
's drive to a matching fifty gee.

"Give me five more minutes. Remember why I'm here. It's to keep you from doing anything too brave. Look, if we were to hang on our drive with a twenty gee thrust, how close could we get to the
Dotterel
?"

"We'd have to make sure we didn't fry them with our drive," said Wenig. He was busy for a couple of minutes at the computer, while I tried again to make sense of the pieces.

"We can get so we're about sixty thousand kilometers from them," said Wenig at last. "If we want to talk to them through the microwave radar link, the best geometry would be one where we're seeing them side-on. We'd have decent clearance from both drives there. Ready to do it?"

"One minute more." I was getting a feeling, a sense that everything that McAndrew had done had been guided by a single logic. "Look, I asked you what would happen if the drive failed when the life-capsule was up close to the mass disk, and you said the system would move the capsule back out again. But look at it the other way round now. Suppose the drive works fine—and suppose it was the system that's supposed to move the life-capsule up and down the column that wouldn't work? What would that do?"

Wenig stroked at his luxuriant mustache. "I don't think it could happen, the design looked good. If it did, everything would depend where the capsule stuck."

"Suppose it stuck up near the disk, when the ship was on a high-thrust drive."

"Well, that would mean there was a big gravitational acceleration. You'd have to cancel it out with the drive, or the passengers would be flattened." He paused. "It would be a bugger. You wouldn't dare to turn the drive
off
—you'd need it on all the time, so that your acceleration compensated for the gravity of the disk."

"Damn right. If you couldn't get yourself farther from the disk, you'd be forced to keep on accelerating. That's what happened to the
Merganser
, I'll bet my pension on it. Get the designs of the capsule movement-train up on the screen, and let's see if we can spot anything wrong with it."

"You're an optimist, Captain Roker." He shrugged. "We can do it, but those designs have been looked at twenty times. Look, I see what you're saying, but I find it hard to swallow. What was McAndrew doing when he came back through the system and then out again?"

"The only thing he
could
do. He couldn't switch the drive off, even though he could turn the ship around. He could fly off to God knows where in a straight line—that way we'd never have found him. Or he could fly in bloody great circles, and we'd have been able to see him but never get near to him for more than a couple of minutes at a time—there's no other manned ship that could match that fifty gee thrust. Or he could do what he did do. He flew back through the System to tell us the direction he was heading, out to HC-183. And he balanced here on his drive tail, and sat and waited for us to get smart enough to figure out what he was doing."

I paused for breath, highly pleased with myself. Out of a sphere of trillions of cubic miles, we had tracked the
Merganser
to its destination. Wenig was shaking his head and looking very unhappy.

"What's wrong," I said cockily. "Find the logic hard to follow?"

"Not at all. A rather trivial exercise." He looked down his nose at me. "But you don't seem able to follow your own ideas to a conclusion. McAndrew knows all about
this
ship. He knows it can accelerate at the same rate as
Merganser
. So your idea that he couldn't fly around in big circles and wait for us to match his position can't be right—the
Dotterel
could do that."

He was right.

"So why didn't Mac do that? Why did he come out all this way?"

"I can only think of one answer. He's had the chance to look at the reason the life capsule can't be moved back along the axis, so the drive mustn't be switched off. And he thinks that this ship has the same problem."

I nodded. "See now why I wouldn't let you take the
Dotterel
all the way up to fifty gee?"

"I do. You were right, and I would have taken us into trouble if you hadn't been along. Now then"—Wenig looked gloomier than ever at some new thought—"let's take the logic a step farther. McAndrew is hanging down there near HC-183 in a fifty gee gravity field. We can't get there to help him unless we do the same, and we're agreed that we dare not do that, or we'll end up with the same difficulty that he has, and we won't be able to turn off the drive."

I looked out of the port, toward the dark bulk of HC-183 and the
Merganser
, hovering on its plume of high-temperature plasma. Wenig was right. We daren't go down there.

"So how are we going to get them out?"

Wenig shrugged, "I wish I could tell you. Maybe McAndrew has an answer. If not, they're as inaccessible as if they were halfway to Alpha Centauri and still accelerating. We've got to get into communication with them."

* * *

When I was about eleven years old, just before puberty, I had a disturbing series of dreams. Night after night, for maybe three months, I seemed to wake on the steep face of a cliff. It was dark, and I could barely see handholds and toeholds in the rock.

I had to get to the top—something was hidden below, invisible behind the curve of the black cliff face. I didn't know what it was, but it was awful.

Every night I would climb, as carefully as I could; and every night there would come a time when I missed a handhold, and began to slide downwards, down into the pit and the waiting monster.

I woke just as I reached the bottom, just as I was waiting for the first sight of my pit beast.