Hidden Variables (43 page)

"Lava, and fractures in the rock," I said. "Every year at perihelion, about two percent of Quake's surface gets covered with lava and hot ashes. That may not sound like a lot, but even the parts that don't get covered are affected by the eruptions. What you're looking at is one of last year's, or maybe the year before. The plants haven't had time to grow back yet. They'll do it all right, and they find rich soil there when the lava decomposes, but it takes a few years. Come back in ten years and there'll be a whole new set of scars, in many different places. That's one of the problems with Quake. The eruptions seem to come in different places each year."

Rebka was looking suitably chastened. "What's the radius of Quake?"

"About fifty-four hundred kilometers—the Carmel sisters could be anywhere in three hundred and fifty million square kilometers."

"Yet you are still convinced that you can find them?"

"We have a good chance. I'm betting that they have stayed within hover-car range of the foot of the umbilical. And they will want to be near water. I think that tells us where to look—if we can look there in time."

He nodded thoughtfully. "You were quite right. This would be impossible without someone who knows the summer surface of the planet. I would be useless alone."

So he had considered that option. That proved he was either braver or more foolish than anyone else I knew—perhaps both.

"Suppose we don't get to them," he went on. "There must still be a chance that they would survive perihelion. How good would that chance be?"

I had to think hard about that one. Could they survive summertide maximum? I had, in a manner of speaking, but that could be put down to blind fortune.

I shrugged. "I'd give them maybe five percent. No more, and probably less. What will you do if they get killed there?"

I should have realized that my question would upset him as much as my answer. Rebka winced at the thought.

"I will blame myself," he said. "I am the one who has pursued them across four systems. If I had been less clumsy in pursuit—in signalling my approach—perhaps they would not have fled to Dobelle. We must save them, if they cannot save themselves. How do the native animals survive—can you give me any details?"

No comfort for him there. "Most of them don't," I said. "They all dig deep down, but the biologists who've looked at the fauna here reckon that at least half of the animals are killed off each year. They can breed fast enough to keep up, but overpopulation doesn't ever seem to be a problem on Quake."

He nodded again and fell silent. He was acting more like the guardian of the Carmel sisters than their pursuer, but it suited me fine if he would keep his mind on them. In a miserable silence, we approached the foot of the umbilical. When we got near enough to see clearly where it joined the surface of Quake, Rebka saw something that brought him out of his introspection.

"What's going on there?" he said, as we reached the end of the drive train and prepared to descend to the surface.

He was pointing off to one side, where the first stage of loosening of the tether had begun. The heavy cables had already been deployed around the tether end, as it lay like a broad inverted mushroom on the surface.

"They're getting the tether loose, ready for midsummer."

"I thought you said that the connection with the planet was permanent?"

"It is. It always provides the tension we need to stabilize the load cable. But at midsummer maximum we can't risk a simple mechanical contact, the way we have over on Egg. In a few more Days we'll draw the end of the umbilical up to about three thousand meters from the surface, well away from danger of real damage during the eruptions at tidal maximum. We have to be back here long before that happens."

"So you are telling me that there is no permanent coupling?"

I shrugged, and opened the door of the passenger car. We had reached the end of the line, the surface of Quake. So far, everything about us looked peaceful, with no obvious signs of seismic activity. We had to get the hovercar ready and be on our way as soon as possible.

"It depends what you call a coupling," I replied. "We keep the tension in the cable through midsummer with a magnetic hold. Quake is full of ferromagnetics, and the umbilical has a generator in its tether. We just use Quake as a big lump of iron. The bond is as strong as a mechanical one, and it doesn't need a contact with the surface. You'll see, it works fine."

"And how do you get off the surface when the umbilical is drawn up?"

I looked back at him before I set my foot down onto Quake's surface. "That's what I've been trying to say. You don't. That's why we have to be back here in twenty hours or less."

I was getting through to him. It was no good getting back to this point, unless we could do it in time. I went on with the unshipping of the hover-craft from the cargo pod that had followed us down, while Rebka walked over to the cables that hung loosely by the edge of the tether. He was inspecting them closely.

"We could still use one of those, couldn't we?" he said. "It looks as though they will still be hanging down to the surface. Couldn't they serve as an emergency hoist to the bottom of the umbilical?"

I went over and took a look for myself. He was right, the cables would hang down to the surface, even when the umbilical was high in the sky. I looked at their size and weight, then went back to the hover-car.

"Rather you than me, but I suppose you're right. In fact, I think that if you look at the specifications on the umbilical, you'll find a statement that says the cables can form an emergency system."

"I gather that you do not regard them as such."

I shrugged and climbed into the driver's seat on the hovercraft. "It all depends what you define as an emergency system. If I open my shirt and look at my chest I find I've got two nipples, and I guess they're my emergency system in case I ever get pregnant. I'm hoping the idea that we'll have to shin up those cables is somewhere about the same level of probability. I never thought of using them before, and I handle all the shipment of materials from here to Egg and back."

"Do you like your work?"

I didn't care for his change of subject.

"It's a good job. It passes the time."

Since we had nothing else to do for a couple of hours, while we drove off towards the lake side, it looked as though Rebka was proposing to try his hand on me. I felt I had to improve on my last answer.

"I wouldn't change it for any job on Egg or Quake, so I guess I like it."

Leave me alone, Rebka, my tone said. Not a chance. "Do you realize how fond Governor Wethel is of you, Captain Mira?"

"Wethel? I always thought he felt uncomfortable with me." I had set the speed to forward maximum, and was skimming us across the quiet surface of Quake. It was hard to believe that all this peace would soon be broken.

"He is uncomfortable with you. Most uncomfortable. Do you know why?"

Wethel wasn't any more uncomfortable than I was. How rude could I be to a Sector Moderator? "No, I have no idea why."

"Then I will tell you. He is uncomfortable because he is convinced that you could do his job much better than he can."

I was tempted to look round at him, but at the speed we were going it could be fatal.

"I couldn't do his job at all. I couldn't stand it. In fact, if you want to know the truth I once refused it."

"I know. Three and a half years ago, after your second visit to Quake in summer, and before your third visit."

Damn the man. I didn't know just how long he had been in the Dumbbell system, but he seemed to have found out everybody's whole life history.

"And that's exactly why Wethel feels it's really your job," went on Rebka calmly. "You refused it—so he feels like a second choice, with the first choice there to prove it."

I was holding the controls so hard that I thought they ought to snap off in my hands. This type of conversation may be nothing to Rebka, but I couldn't take it—and where it was leading. The sudden orange glow in the sky ahead of us was exactly what I needed. I switched the screen to maximum transparency.

"See that?" As I spoke, the tremor shook the car. We were travelling on a meter-deep cushion of air, but we were also skimming forward at forty kilometers an hour. The ground ahead was moving in smooth, linear waves, rippling out from the quake center. Driving the hover-car over them was like sitting in a power boat and shooting the Grand Rapid on Egg's eastern limb.

Ten seconds after the land waves we heard the deep rumble of the eruption. Rebka had moved forward to sit next to me, craning closer to the front screen.

"Is that a big one?"

"Medium size. I'd say it's fifteen kilometers away. You'll see break-outs ten times that big in another five hours, when we're really getting in to the maximum tidal force. Hold tight now. We'll hit the secondary wave front in a second, and that'll be choppy."

As we came to the region where surface and body waves had created their complicated interference pattern I had to slow our speed. The hover-car was rolling and yawing, even when I cut us to walking pace. It wasn't a bad quake—for Quake—but it had given Rebka something else to think about. We were going to see more and worse before we reached the Carmel twins.

The early records of the Dumbbell System make interesting reading. The first settlement party had arrived at Eta-Cass A in the winter months of Dumbbell, and had the choice of landing on Egg or on Quake. It looked like an easy decision. Quake was more fertile, it had lots of metals and available radioactives, and it was less humid and muggy than Egg. I'm used to the Egg climate, but I must say I wouldn't care to live over on Cloudside.

The settlers put small camps on both planets, but they made it clear that Egg would be a temporary facility, only to be used for general exploration.

The tone of the old records on Quake gradually changes as their first summer approached. They knew it would be hot, because the orbit of Dumbbell had been known since the first scout ship came through. What worried them was something else. They could see recent evidence of widespread vulcanism, even though there had been no signs of volcanic activity when they landed.

Dumbbell swept in closer to the sun. The temperature shot up, all the plants began to die off and root deeper, and the earth tremors began. Even then, no one seemed to realize how bad it would get.

One colony camp stuck it out until three Days before summer maximum, before they finally gave up and ran over to Egg for shelter under the clouds.

Reading between the lines, you can detect another tone in those old records. It is almost one of disbelief. If Quake is as inhospitable to life as this, they seem to say, how could life ever have arisen here in the first place?

It took several hundred years before anyone could definitively answer that old question. The gas-giant, Perling, orbiting Eta-Cass A seven hundred million kilometers farther out, emerged as the villain of the story. Dumbbell had circled its sun peacefully for several billion years, not changing much in climate or distance. Life had emerged and developed on both Quake and Egg. It had been a tranquil environment on both members of the planet pair, until a third component of the planetary system, perturbed by the gravitational forces of the dwarf sun Eta-Cass B, had suffered a close encounter with Perling, two hundred times its mass. The giant had thrown it into a close swing-by of Eta-Cass A, from which it should have emerged with an eccentric but stable orbit. But Dumbbell lay in its path.

The stranger had done a complex dance about the doublet, moving the components closer together and changing their combined orbit to one that now skimmed much nearer to Eta-Cass A at perihelion—the present orbit. And the other planet had been slung clear out of the system by the encounter. Somewhere in interstellar space there was a solitary planet on an endless journey, waiting for encounter with and possible capture by another sun.

I couldn't help wondering about the old Quake, the planet before the encounter that gave it its present orbit and unruly surface. Had it been a true garden planet, with tranquil streams and clean, fragrant air? The present atmosphere was breathable, but near summer there was always a faint sulphurous smell to the air, a reminder that new eruptions were on the way to buckle and scar the face of Quake. I didn't mind it, but Rebka had reacted strongly when we first encountered that faint smell. He was sitting near a side window that had been left cracked open— everything would have to be closed as the sun rose, so that the air-cooler could do its job, but near dawn the temperature was still tolerable.

When the breeze carried in its trace of sulphur, Rebka had stiffened and sniffed. He seemed like a hunting animal, turning to track a scent. It took his mind off the thought of the eruptions ahead of us.

"You all right?" I asked. He was acting strangely, head rigid and cocked to one side.

He leaned back, and nodded. "That smell brings back old memories too clearly. I had an experience on Luytens, a long time ago. Curious, how strongly the stimulus of smells can affect our recall."

So I was not the only one who could be troubled by my memories. I didn't know if I was pleased or worried. It was easy to think of Rebka as a superman, the image that the words 'Sector Moderator' carried with them. If he was as frail and human as I was, it was good to know that. We might need a superman in the hours ahead, but if we didn't have one it was better to know it ahead of time.

Rebka reached out and closed the side window. The thermometer was beginning to show a rapid rise outside the car, and we might as well enjoy cool air while we could—I knew that soon enough we would have to go outside.

We were traveling now across a sea of dry spiky plants that cracked and powdered beneath the skirts of the hover-car. It was hard to believe that the brittle stems had been healthy and growing less than ten Days before.

"I don't understand how life survived here," said Rebka, peering out at the dead landscape. "After the orbit changed, everything else must have changed too. Temperatures, seasons, even the atmosphere. How could the life forms have endured?"