The Gateway Trip

by Frederik Pohl

  “And the conclusion you can draw from that,” I agreed, “is that as nothing new has been found lately, the planet has probably been mined dry. You’re right. That’s what the evidence seems to show. The first diggers found everything useful that there was to be found…so far.”

  “But you think there’s more.”

  “I hope there’s more. Look. Item. The tunnel walls. You see they’re all alike—the blue walls, perfectly smooth; the light coming from them that never varies; the hardness. How do you suppose the Heechee made them?”

  “Why, I don’t know.”

  “Neither do I. Or anybody else. But every Heechee tunnel is the same, and if you dig into them from the outside you find the same basic substrate rock, then a boundary layer that’s sort of half wall-metal and half substrate, then the wall itself. Conclusion: The Heechee didn’t dig the tunnels and then line them, they had something that crawled around underground like an earthworm, leaving these tunnels behind. And one other thing: they overdug. That’s to say they dug lots of tunnels they didn’t need, going nowhere, never used for anything. Does that suggest anything to you?”

  “It must have been cheap and easy?” she guessed.

  I nodded. “So it was probably an automatic machine, and there really ought to be at least one of them, somewhere on this planet, to find. Next item. The air. They breathed oxygen like we do, and they must have got it from somewhere. Where?”

  “Why, there’s oxygen in the atmosphere, isn’t there?”

  “Hardly any. Less than a half of a percent. And most of what there is isn’t free oxygen; it’s compounded into carbon dioxide and other garbage. There’s no water vapor to speak of, either. Oh, a little—not as much as, for instance, sulfur dioxide. When water seeps out of the rock it doesn’t come out as a fresh, clear spring. It goes into the air as vapor pretty fast. It rises—the water molecule being lighter than the carbon dioxide molecule. When it reaches a point where the sun can get at it it splits into hydrogen and oxygen. The oxygen and half the hydrogen mostly go into turning the sulfur dioxide into sulfuric acid. The rest of the hydrogen just escapes into space.”

  She was looking at me quizzically. “Audee,” she said gently, “I already believe you’re an expert on Venus.”

  I grinned. “But do you get the picture?”

  “I think so. It looks pretty bad.”

  “It is pretty bad, but all the same the Heechee managed to get that little bit of oxygen out of the mixture, cheaply and easily—remember those extra tunnels they filled—along with inert gases like nitrogen—and they’re present only in trace amounts—enough to make a breathing mixture. How? I don’t know, but if there’s a machine that did it I’d like to find that machine. Next item: aircraft. The Heechee flew around the surface of Venus a lot.”

  “So do you, Audee! Aren’t you a pilot?”

  “Airbody pilot, yes. But look what it takes to make an airbody go. There’s a surface temperature of seven-thirty-five K, and not enough oxygen to keep a cigarette lit. So my airbody has to have two fuel tanks, one for the fuel, one for the thing to burn it with. That’s not just oil and air, you know.”

  “It isn’t?”

  “Not here, Dorotha. Not at the kind of ambient temperatures we’ve got. It takes exotic fuels to get that hot. Did you ever hear of a fellow named Carnot?”

  “Old-time scientist, was he? The Carnot cycle fellow?”

  “Right again.” That was the third time she’d surprised me, I noted cautiously. “The Carnot efficiency of an engine is expressed by its maximum temperature—the heat of combustion, let’s say—divided by the temperature of its exhaust. Well, but the temperature of the exhaust can’t be lower than the temperature of whatever it’s exhausted into—otherwise you’re not running an engine, you’re running a refrigerator. And you’ve got that seven-thirty-five air temperature to fight, so even with special fuels you have basically a lousy engine. Any heat engine on Venus is lousy. Did you ever wonder why there are so few airbodies around? I don’t mind; it helps to have something close to a monopoly. But the reason is that they’re so damn expensive to run.”

  “And the Heechee did it better?”

  “I think they did.”

  She laughed again, unexpectedly and once more very attractively. “Why, you poor fellow,” she said in good humor, “you’re hooked on the stuff you sell, aren’t you? You think that one of these days you’re going to find the mother tunnel and pick up a few billion dollars’ worth of Heechee stuff!”

  I wasn’t pleased with the way she put that. I wasn’t all that happy with the meeting I had set up with Vastra’s Third, for that matter; I’d figured that, away from her boyfriend, I could pick this Dorotha Keefer’s brains about him pretty easily. It wasn’t working out that way. She was making me aware of her as a person, which was an undesirable development in itself—you can’t treat a mark as a mark if you think of him, or her, as a fellow human being.

  Worse than that, she was making me take a good look at myself.

  So I just said, “You may be right. But I’m sure going to give it a good try.”

  “You’re angry, aren’t you?”

  “No,” I lied, “but maybe a little tired. And we’ve got a long trip tomorrow, so I’d better take you back to the Spindle, Miss Keefer.”

  V

  My airbody was roped down at the edge of the spacepad and was reached the same way the spacepad was reached: elevator to the surface lock, then a sealed tractor cab to carry us across the dry, rocky, tortured surface of Venus, peeling away under the high-density wind. Normally I kept the airbody under a lashed-down foam housing, of course. You don’t leave anything free and exposed on the surface of Venus if you want to find it intact when you get back to it, not even if it’s made of chrome steel. I’d had the foam stripped off first thing that morning, when I checked it out and loaded supplies. Now it was ready. I could see it from the bull’s-eye ports of the crawler, through the howling, green-yellow murk outside.

  Cochenour and the girl could have seen it too, if they’d known where to look, but they might not have recognized it as something that would fly.

  “Did you and Dorrie have a fight?” Cochenour screamed in my ear.

  “No fight,” I screamed back.

  “Don’t care if you did. Just wanted to know. You don’t have to like each other, just so you do what I want you to do.” He was silent for a moment, resting his vocal cords. “Jesus. What a wind.”

  “Zephyr,” I told him. I didn’t say any more; he would find out for himself. The area around the spacepad is a sort of natural calm area, by Venusian standards. Orographic lift throws the meanest of the winds up over the pad, and all we get is a sort of confused back eddy. That makes taking off and landing relatively easy. The bad part of that is that some of the heavy metal compounds in the air settle out on the pad. What passes for air on Venus has layers of red mercuric sulfide and mercurous chloride in the lower reaches, and when you get above them to those pretty fluffy clouds tourists see on the way down, you find that some of them are droplets of sulfuric and hydrochloric and hydrofluoric acid.

  But there are tricks to that, too. Navigation over Venus takes 3-D skills. It’s easy enough to proceed from Point A to Point B on the surface. Your transponders will link you to the radio range and map your position continuously on the charts. What’s hard is to find the right altitude. That takes experience and maybe intuition, and that’s why my airbody and I were worth a million dollars to people like Boyce Cochenour.

  By then we were at the airbody, and the telescoping snout from the crawler was poking out to its lock. Cochenour was staring out the bull’s-eye. “It doesn’t have any wings!” he shouted, as though I was cheating him.

  “It doesn’t have sails or snow chains either,” I shouted back. “Get aboard if you want to talk! It’ll be easier in the airbody.”

  We climbed through the little snout, I unlocked the entrance, and we got aboard without much trouble.

  We didn’t
even have the kind of trouble that I might have made for myself. You see, an airbody is a big thing on Venus. I was damn lucky to have been able to acquire it, and, well, I won’t beat around the bush, you could say I loved it. Mine could have held ten people, without equipment. With what Sub Vastra’s outfitting shop had sold us and Local 88 had certified as essential to have on board, it was crowded with just the three of us.

  I was prepared for at least sarcasm. But Cochenour merely looked around long enough to find the best bunk, strode over to it, and claimed it as his. The girl was acting like a good sport about all the inconveniences. And there I was, left with my glands charged up for hostile criticism, and nobody criticizing.

  It was a lot quieter inside the airbody. You could hear the noise of the winds right enough, but it was only annoying. I passed out high-filter earplugs, and with them in place the noise was hardly even annoying.

  “Sit down and strap in,” I ordered, and when they were stowed away I took off.

  At ninety thousand millibars, wings, aren’t just useless, they’re poison. My airbody had all the lift it needed, built right into its seashell-shaped hull. I fed the double fuel mixture into the thermo-jets, we bounced across the reasonably flat ground at the edge of the spacepad (it was bulldozed once a week, which is how it stayed reasonably flat), and we were zooming off into the wild yellow-green yonder—a moment later, into the wild brown-gray yonder—after a run of no more than fifty meters.

  Cochenour had fastened his harness loosely to be comfortable. I enjoyed hearing him yell as he was thrown about in the savage, short-period turbulence. It wouldn’t kill him, and it only lasted for a few moments. At a thousand meters I found our part of Venus’s semipermanent atmospheric inversion, and the turbulence dropped to where I could take off my belt and stand.

  I took the plugs out of my ears and motioned to Cochenour and the girl to do the same.

  He was rubbing his head where he’d bounced into an overhead chart rack, but he was grinning a little. “Pretty exciting,” he admitted, fumbling in his pocket. “All right if I smoke?”

  “They’re your lungs.”

  He grinned more widely. “They are now,” he agreed. “Say, why didn’t you give us those earplugs while we were in the tractor?”

  There is, as you might say, a tide in the affairs of guides, where you either let them flood you with questions and then spend the whole time explaining what that funny little dial means when it turns red…or you keep your mouth shut and go on to do your work and make your fortune. What it came down to was a choice: Was I going to come out of this liking Cochenour and his girlfriend, or not?

  If I was, I should try to be civil to them. More than civil. Living, the three of us, for three weeks in a space about as big as an apartment kitchenette meant that everybody would have to work real hard at being nice to everybody else, if we were going to come back without total hatred. And as I was the one who was being paid to be nice, I should be the one to set an example.

  On the other hand, the Cochenours of the world are sometimes just not likable. If that was going to be the case, the less talk the better, and I should slide questions like that off with something like, “I forgot.”

  But he hadn’t actually gone out of his way to be unpleasant. The girl had even actually attempted friendliness. So I opted for courtesy. “Well, that’s an interesting thing. You see, you hear by differences in pressure. While the airbody was taking off, the plugs filtered out part of the sound—the pressure waves—but when I yelled at you to belt up, the plugs passed the overpressure of my voice and you could hear easily enough. However, there’s a limit. Past about a hundred and twenty decibels—that’s a unit of sound—”

  “I know what a decibel is,” Cochenour growled.

  “Right. Past a hundred and twenty or so the eardrum just doesn’t respond anymore. So in the crawler it was just too loud. You not only got sound in through the hull, it came up from the ground, conducted by the treads. If you’d had the plugs in you wouldn’t even have been able to hear—well, anything at all,” I finished lamely.

  Dorotha had been listening while she repaired her eye makeup. “Anything like what?” she demanded.

  I decided to think of them as friends, at least for the time being. “Like orders to get into your heatsuits. In case of accident, I mean. A gust could’ve tipped that crawler right over, or sometimes solid objects come flying over the hills and hit you before you know it.”

  She was shaking her head, but she was laughing. “Lovely place you took us to, Boyce,” she commented.

  He wasn’t paying any attention. He had something else on his mind. “Why aren’t you flying this thing?” he demanded.

  I got up and activated the virtual globe. “Right,” I said. “It’s time we talked about that. Just now my airbody’s on autopilot, heading in the general direction of this quadrant down here. We have to decide on a specific destination.”

  Dorrie Keefer was inspecting the globe. It isn’t real, of course; it’s just a three-dimensional image that hangs in the air, and you can poke your finger right through it. “Venus doesn’t really look like much,” she commented.

  “Those lines you see,” I explained, “are just radio-range markers; you won’t see them looking out the window. Venus doesn’t have any oceans, and it isn’t cut up into countries, so making a map of it isn’t quite what you’d expect on Earth. See this bright spot here? That’s us. Now look.”

  I overlaid the radio-range grid and the contour colors with geological data. “Those blobby circles are mascon markers. You know what a mascon is?”

  “A concentration of mass. A lump of heavy stuff,” she offered.

  “Fine. Now see what happens when I phase in the locations of known Heechee digs.”

  When I hit the control the digs appeared as golden patterns, like worms crawling across the planet. Dorotha said at once, “They’re all in the mascons.”

  Cochenour gave her a look of approval, and so did I. “Not quite all,” I corrected. “But damn near. Why? I don’t know. Nobody knows. The mascons are mostly older, denser rock—basalt and so on—and maybe the Heechee felt safer with strong, dense rock around them.” In my correspondence with Professor Hegramet back on Earth, in the days when I didn’t have a dying liver in my gut and thus could afford to take an interest in abstract knowledge, we had kicked around the possibility that the Heechee digging machines would only work in dense rock, or rock of a certain chemical composition. But I wasn’t prepared to discuss some of the ideas I’d gotten from Professor Hegramet with them.

  I rotated the virtual globe slightly by turning a dial. “See over here, where we are now. This formation’s Alpha Regio. There’s the big digging which we just came out of. You can see the shape of the Spindle. That particular mascon where the Spindle is is called Serendip; it was discovered by a hesperological—”

  “Hesperological?”

  “By a geological team studying Venus, which makes it a hesperological team. They detected the mass concentration from orbit, then after the landings they drilled out a core sample there and hit the first Heechee dig. Now these other digs you see in the northern high latitudes are all in this one bunch of associated mascons. There are interventions of less dense rock between them, and they tunnel right through to connect, but they’re almost all right in the mascons.”

  “They’re all north,” Cochenour said sharply. “We’re going south. Why?”

  It was interesting that he could read the virtual globe, but I didn’t say so. I only said, “The ones that are marked are no good. They’ve been probed already.”

  “Some of them look even bigger than the Spindle.”

  “A hell of a lot bigger, right. But there’s nothing much in them, or anyway not much chance that anything in them is in good enough shape to bother with. Subsurface fluids filled them up a hundred thousand years ago, maybe more. A lot of good men have gone broke trying to pump one out and excavate, without finding anything. Ask me. I was one of them.”
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  “I didn’t know Venus had any liquid water,” Cochenour objected.

  “I didn’t say water, did I? But as a matter of fact some of it was, or anyway a sort of oozy mud. Apparently water cooks out of the rocks and has a transit time, getting to the surface, of some thousands of years before it seeps out, boils off, and cracks to hydrogen and oxygen and gets lost. In case you didn’t know it, there’s some under the Spindle. It’s what you were drinking, and what you were breathing, while you were there.”

  “We weren’t breathing water,” he corrected.

  “No, of course not. We were breathing air that we made. But sometimes the tunnels still have kept their air—I mean the original stuff, the air the Heechee left behind them. Of course, after a few hundred thousand years they generally turn into ovens. Then they tend to bake everything organic away. Maybe that’s why we’ve found so little of, let’s say, animal remains—they’ve been cremated. So—sometimes you might find air in a dig, but I’ve never heard of anybody finding drinkable water in one.”

  Dorotha said, “Boyce, this is all very interesting, but I’m hot and dirty and all this talk about water’s getting to me. Can I change the subject for a minute?”

  Cochenour barked; it wasn’t really a laugh. “Subliminal prompting, Walthers, don’t you agree? And a little old-fashioned prudery too, I expect. I think what Dorrie really wants to do is go to the toilet.”

  Given a little encouragement from the girl, I would have been mildly embarrassed for her. She was evidently used to Cochenour. She only said, “If we’re going to live in this thing for three weeks, I’d like to know what it offers.”

  “Certainly, Miss Keefer,” I said.

  “Dorotha. Dorrie, if you like it better.”

  “Sure, Dorrie. Well, you see what you’ve got. There are five bunks; they partition to sleep ten if wanted, but we don’t want. Two shower stalls. They don’t look big enough to soap yourself in, but they’ll do the job if you work at it. Two chemical toilets in those cubbies. Kitchen over there—stove and storage, anyway. Pick the bunk you like, Dorrie. There’s a screen arrangement that comes down when you want it for changing clothes and so on, or just if you don’t want to look at the rest of us for a while.”