"Well, Doc, if this is Der Tag, I hope everything works properly. I'd like a photograph of a brontosaurus as a souvenir."
This sort of banter had been thrown at Henderson so often that he now took it for granted. He smiled without much mirth and replied, "I don't promise anything. It may be the biggest flop ever."
Davis moodily checked the tire pressure with the toe of his boot. It was a new set, he noticed, with an odd zigzag pattern he hadn't seen before.
"Whatever happens, we hope you'll tell us. Otherwise, we're going to break in one night and find out just what you're up to."
Henderson laughed. "You'll be a pair of geniuses if you can learn anything from our present lash-up. But, if all goes well, we may be having a little celebration by nightfall."
"What time do you expect to be back, Chief?"
"Somewhere around four. I don't want you to have to walk back for tea."
"O.K.—here's hoping!"
The machine disappeared in a cloud of dust, leaving two very thoughtful geologists standing by the roadside. Then Barton shrugged his shoulders.
"The harder we work," he said, "the quicker the time will go. Come along!"
The end of the trench, where Barton was working with the power drill, was now more than a hundred yards from the main excavation. Davis was putting the final touches to the last prints to be uncovered. They were now very deep and widely spaced, and looking along them, one could see quite clearly where the great reptile had changed its course and started, first to run, and then to hop like an enormous kangaroo. Barton wondered what it must have felt like to see such a creature bearing down upon one with the speed of an express; then he realized that if their guess was true this was exactly what they might soon be seeing.
By mid-afternoon they had uncovered a record length of track. The ground had become softer, and Barton was roaring ahead so rapidly that he had almost forgotten his other preoccupations. He had left Davis yards behind, and both men were so busy that only the pangs of hunger reminded them when it was time to finish. Davis was the first to notice that it was later than they had expected, and he walked over to speak to his friend.
"It's nearly half-past four!" he said when the noise of the drill had died away. "The Chiefs late—I'll be mad if he's had tea before collecting us."
"Give him another half-hour," said Barton. "I can guess what's happened. They've blown a fuse or something and it's upset their schedule."
Davis refused to be placated. "I'll be darned annoyed if we've got to walk back to camp again. Anyway, I'm going up the hill to see if there's any sign of him."
He left Barton blasting his way through the soft rock, and climbed the low hill at the side of the old riverbed. From here one could see far down the valley, and the twin stacks of the Henderson-Barnes laboratory were clearly visible against the drab landscape. But there was no sign of the moving dust-cloud that would be following the jeep: the Professor had not yet started for home.
Davis gave a snort of disgust. There was a two-mile walk ahead of them, after a particularly tiring day, and to make matters worse they'd now be late for tea. He decided not to wait any longer, and was already walking down the hill to rejoin Barton when something caught his eye and he stopped to look down the valley.
Around the two stacks, which were all he could see of the laboratory, a curious haze not unlike a heat tremor was playing. They must be hot, he knew, but surely not that hot. He looked more carefully, and saw to his amazement that the haze covered a hemisphere that must be almost a quarter of a mile across.
And, quite suddenly, it exploded. There was no light, no blinding flash; only a ripple that spread abruptly across the sky and then was gone. The haze had vanished—and so had the two great stacks of the power-house.
Feeling as though his legs had turned suddenly to water, Davis slumped down upon the hilltop and stared open-mouthed along the valley. A sense of overwhelming disaster swept into his mind; as in a dream, he waited for the explosion to reach his ears.
It was not impressive when it came; only a dull, long-drawn-out whoooooosh! that died away swiftly in the still air. Half unconsciously, Davis noticed that the chatter of the drill had also stopped; the explosion must have been louder than he thought for Barton to have heard it too.
The silence was complete. Nothing moved anywhere as far as his eye could see in the whole of that empty, barren landscape. He waited until his strength returned; then, half running, he went unsteadily down the hill to rejoin his friend.
Barton was half sitting in the trench with his head buried in his hands. He looked up as Davis approached; and although his features were obscured by dust and sand, the other was shocked at the expression in his eyes.
"So you heard it too!" Davis said. "I think the whole lab's blown up. Come along, for heaven's sake!"
"Heard what?" said Barton dully.
Davis stared at him in amazement. Then he realized that Barton could not possibly have heard any sound while he was working with the drill. The sense of disaster deepened with a rush; he felt like a character in some Greek tragedy, helpless before an implacable doom.
Barton rose to his feet. His face was working strangely, and Davis saw that he was on the verge of breakdown. Yet, when he spoke, his words were surprisingly calm.
"What fools we were!" he said. "How Henderson must have laughed at us when we told him that he was trying to see into the past!"
Mechanically, Davis moved to the trench and stared at the rock that was seeing the light of day for the first time in fifty million years. Without much emotion, now, he traced again the zigzag pattern he had first noticed a few hours before. It had sunk only a little way into the mud, as if when it was formed the jeep had been traveling at its utmost speed.
No doubt it had been; for in one place the shallow tire marks had been completely obliterated by the monster's footprints. They were now very deep indeed, as if the great reptile was about to make the final leap upon its desperately fleeing prey.
JUPITER FIVE
Professor Forster is such a small man that a special space-suit had to be made for him. But what he lacked in physical size he more than made up—as is so often the case—in sheer drive and determination. When I met him, he'd spent twenty years pursuing a dream. What is more to the point, he had persuaded a whole succession of hard-headed business men, World Council Delegates and administrators of scientific trusts to underwrite his expenses and to fit out a ship for him. Despite everything that happened later, I still think that was his most remarkable achievement. . . .
The "Arnold Toynbee" had a crew of six aboard when we left Earth. Besides the Professor and Charles Ashton, his chief assistant, there was the usual pilot-navigator-engineer triumvirate and two graduate students—Bill Hawkins and myself. Neither of us had ever gone into space before, and we were still so excited over the whole thing that we didn't care in the least whether we got back to Earth before the next term started. We had a strong suspicion that our tutor had very similar views. The reference he had produced for us was a masterpiece of ambiguity, but as the number of people who could even begin to read Martian script could be counted, if I may coin a phrase, on the fingers of one hand, we'd got the job.
As we were going to Jupiter, and not to Mars, the purpose of this particular qualification seemed a little obscure, though knowing something about the Professor's theories we had some pretty shrewd suspicions. They were partly confirmed when we were ten days out from Earth.
The Professor looked at us very thoughtfully when we answered his summons. Even under zero g he always managed to preserve his dignity, while the best we could do was to cling to the nearest handhold and float around like drifting seaweed. I got the impression—though I may of course be wrong—that he was thinking: What have I done to deserve this? as he looked from Bill to me and back again. Then he gave a sort of "It's too late to do anything about it now" sigh and began to speak in that slow, patient way he always does when he has something to explain. At least, he alw
ays uses it when he's speaking to us, but it's just occurred to me—oh, never mind.
"Since we left Earth," he said, "I've not had much chance of telling you the purpose of this expedition. Perhaps you've guessed it already."
"I think I have," said Bill.
"Well, go on," replied the Professor, a peculiar gleam in his eye. I did my best to stop Bill, but have you ever tried to kick anyone when you're in free fall?
"You want to find some proof—I mean, some more proof—of your diffusion theory of extraterrestrial culture."
"And have you any idea why I'm going to Jupiter to look for it?"
"Well, not exactly. I suppose you hope to find something on one of the moons."
"Brilliant, Bill, brilliant. There are fifteen known satellites, and their total area is about half that of Earth. Where would you start looking if you had a couple of weeks to spare? I'd rather like to know."
Bill glanced doubtfully at the Professor, as if he almost suspected him of sarcasm.
"I don't know much about astronomy," he said. "But there are four big moons, aren't there? I'd start on those."
"For your information, lo, Europa, Ganymede and Cal-listo are each about as big as Africa. Would you work through them in alphabetical order?"
"No," Bill replied promptly. "I'd start on the one nearest Jupiter and go outward."
"I don't think we'll waste any more time pursuing your logical processes," sighed the Professor. He was obviously impatient to begin his set speech. "Anyway, you're quite wrong. We're not going to the big moons at all. They've been photographically surveyed from space and large areas have been explored on the surface. They've got nothing of archaeological interest. We 're going to a place that's never been visited before."
"Not to Jupiter!" I gasped.
"Heavens no, nothing as drastic as that! But we're going nearer to him than anyone else has ever been."
He paused thoughtfully.
"It's a curious thing, you know—or you probably don't —that it's nearly as difficult to travel between Jupiter's satellites as it is to go between the planets, although the distances are so much smaller. This is because Jupiter's got such a terrific gravitational field and his moons are traveling so quickly. The innermost moon's moving almost as fast as Earth, and the journey to it from Ganymede costs almost as much fuel as the trip from Earth to Venus, even though it takes only a day and a half.
"And it's that journey which we're going to make. No one's ever done it before because nobody could think of any good reason for the expense. Jupiter Five is only thirty kilometers in diameter, so it couldn't possibly be of much interest. Even some of the outer satellites, which are far easier to reach, haven't been visited because it hardly seemed worth while to waste the rocket fuel."
"Then why are we going to waste it?" I asked impatiently. The whole thing sounded like a complete wild-goose chase, though as long as it proved interesting, and involved no actual danger, I didn't greatly mind.
Perhaps I ought to confess—though I'm tempted to say nothing, as a good many others have done—that at this time I didn't believe a word of Professor Forster's theories. Of course I realized that he was a very brilliant man in his field, but I did draw the line at some of his more fantastic ideas. After all, the evidence was so slight and the conclusions so revolutionary that one could hardly help being skeptical.
Perhaps you can still remember the astonishment when the first Martian expedition found the remains not of one ancient civilization, but of two. Both had been highly advanced, but both had perished more than five million years ago. The reason was unknown (and still is). It did not seem to be warfare, as the two cultures appear to have lived amicably together. One of the races had been insect-like, the other vaguely reptilian. The insects seem to have been the genuine, original Martians. The reptile-people—usually referred to as "Culture X"—had arrived on the scene later.
So, at least, Professor Forster maintained. They had certainly possessed the secret of space travel, because the ruins of their peculiar cruciform cities had been found on —of all. places—Mercury. Forster believed that they had tried to colonize all the smaller planets—Earth and Venus having been ruled out because of their excessive gravity. It was a source of some disappointment to the Professor that no traces of Culture X had ever been found on the Moon, though he was certain that such a discovery was only a matter of time.
The "conventional" theory of Culture X was that it had originally come from one of the smaller planets or satellites, had made peaceful contact with the Martians—the only other intelligent race in the known history of the System—and had died out at the same time as the Martian civilization. But Professor Forster had more ambitious ideas: he was convinced that Culture X had entered the Solar System from interstellar space. The fact that no one else believed this annoyed him, though not very much, for he is one of those people who are happy only when in a minority.
From where I was sitting, I could see Jupiter through the cabin porthole as Professor Forster unfolded his plan. It was a beautiful sight: I could just make out the equatorial cloud belts, and three of the satellites were visible as little stars close to the planet. I wondered which was Ganymede, our first port of call.
"If Jack will condescend to pay attention," the Professor continued, "I'll tell you why we're going such a long way from home. You know that last year I spent a good deal of time poking among the ruins in the twilight belt of Mercury. Perhaps you read the paper I gave on the subject at the London School of Economics. You may even have been there—I do remember a disturbance at the back of the hall.
"What I didn't tell anyone then was that while I was on Mercury I discovered an important clue to the origin of Culture X. I've kept quiet about it, although I've been sorely tempted when fools like Dr. Haughton have tried to be funny at my expense. But I wasn't going to risk letting someone else get here before I could organize this expedition.
"One of the things I found on Mercury was a rather well preserved bas-relief of the Solar System. It's not the first that's been discovered—as you know, astronomical motifs are common in true Martian and Culture X art. But there were certain peculiar symbols against various planets, including Mars and Mercury. I think the pattern had some historic significance, and the most curious thing about it is that little Jupiter Five—one of the least important of all the satellites—seemed to have the most attention drawn to it. I'm convinced that there's something on Five which is the key to the whole problem of Culture X, and I'm going there to discover what it is."
As far as I can remember now, neither Bill nor I was particularly impressed by the Professor's story. Maybe the people of Culture X had left some artifacts on Five for obscure reasons of their own. It would be interesting to unearth them, but hardly likely that they would be as important as the Professor thought. I guess he was rather disappointed at our lack of enthusiasm. If so it was his fault since, as we discovered later, he was still holding out on us.
We landed on Ganymede, the largest moon, about a week later. Ganymede is the only one of the satellites with a permanent base on it; there's an observatory and a geophysical station with a staff of about fifty scientists. They were rather glad to see visitors, but we didn't stay long as the Professor was anxious to refuel and set off again. The fact that we were heading for Five naturally aroused a good deal of interest, but the Professor wouldn't talk and we couldn't; he kept too close an eye on us.
Ganymede, by the way, is quite an interesting place and we managed to see rather more of it on the return journey. But as I've promised to write an article for another magazine about that, I'd better not say anything else here. (You might like to keep your eyes on the National Astrographic Magazine next Spring.)
The hop from Ganymede to Five took just over a day and a half, and it gave us an uncomfortable feeling to see Jupiter expanding hour by hour until it seemed as if he was going to fill the sky. I don't know much about astronomy, but I couldn't help thinking of the tremendous gravity field into
which we were falling. All sorts of things could go wrong so easily. If we ran out of fuel we'd never be able to get back to Ganymede, and we might even drop into Jupiter himself.
I wish I could describe what it was like seeing that colossal globe, with its raging storm belts spinning in the sky ahead of us. As a matter of fact I did make the attempt, but some literary friends who have read this MS advised me to cut out the result. (They also gave me a lot of other advice which I don't think they could have meant seriously, because if I'd followed it there would have been no story at all.)
Luckily there have been so many color close-ups of Jupiter published by now that you're bound to have seen some of them. You may even have seen the one which, as I'll explain later, was the cause of all our trouble.
At last Jupiter stopped growing: we'd swung into the orbit of Five and would soon catch up with the tiny moon as it raced around the planet. We were all squeezed in the control room waiting for our first glimpse of our target. At least, all of us who could get in were doing so. Bill and I were crowded out into the corridor and could only crane over other people's shoulders. Kingsley Searle, our pilot, was in the control seat looking as unruffled as ever: Eric Fulton, the engineer, was thoughtfully chewing his mustache and watching the fuel gauges, and Tony Groves was doing complicated things with his navigation tables.
And the Professor appeared to be rigidly attached to the eyepiece of the teleperiscope. Suddenly he gave a start and we heard a whistle of indrawn breath. After a minute, without a word, he beckoned to Searle, who took his place at the eyepiece. Exactly the same thing happened, and then Searle handed over to Fulton. It got a bit monotonous by the time Groves had reacted identically, so we wormed our way in and took over after a bit of opposition.
I don't know quite what I'd expected to see, so that's probably why I was disappointed. Hanging there in space was a tiny gibbous moon, its "night" sector lit up faintly by the reflected glory of Jupiter. And that seemed to be all.