first halted. He recovered his arrows and returned to the cave, opening his face-plate as
he came.
“All x, sweetheart?” he asked, rolling away the boulders. “Didn’t get anything
through to you, did they ?”
“No, they didn’t even realize that I was taking part in the battle, I guess. Did they
hurt you while they had you down ? I was scared to death for a minute.”
“No, the old armor held. One of them must’ve gnawed on my ankle some,
between the greave and the heel-plate, but he couldn’t quite get through. ‘Sa darn small
opening there, too—must’ve bent my foot ‘way round to get in at all. Have to tighten that
joint up a little, I guess. I’ll bet I’ve got a black and blue spot there the size of my hand—
maybe it’s only the size of yours, though.”
“You won’t die of that, probably. Heavens, Steve, that cleaver of yours is a
frightful thing in action! Suppose it’s safe for us to go home?”
“Absolutely—right now’s the best chance we’ll ever have, and something tells me
that we’d better make it snappy. They’ll be back, and next time they won’t be so easy to
take.”
“All x, then—hold me, Steve, I can’t stand the sight of that, let alone wade
through it. I’m going to faint or something, sure.”
“As you were!” he snapped. “You aren’t going to pass out now that it’s all over!
It’s a pretty ghastly mess, I know, but shut your eyes and I’ll carry you out of sight.”
“Aren’t we out of sight of that place yet?” she demanded after a time.
“Have been for quite a while,” he confessed, “but you’re sitting pretty, aren’t you
? And you aren’t very heavy —not here on Ganymede, anyway!”
“Put me down!” she commanded. “After that crack I won’t play with you any more
at all—I’ll pick up my marbles and go home!”
He released her and they hurried back toward their waterfall, keeping wary eyes
sharp-set for danger in any form, animal or vegetable. On the way back across the
foothills Stevens shot another hexaped, and upon the plateau above the river Nadia
bagged several birds and small animals; but it was not until they were actually in their
own little canyon that their rapid pace slackened and their vigilance relaxed.
“After this, ace, we hunt together and we go back to wearing armor while we’re
hunting. It scared me out of a year’s growth when you checked up missing.”
“We sure do, Steve,” she concurred emphatically. “I’m not going to get more than
a meter away from you from now on. What do you suppose those horrible things are ?”
“Which?”
“Both.”
“Those flowers aren’t like anything Tellus ever saw, so we have no basis of
comparison. They may be a development of a kind of flycatcher, or they may be a link
between the animal and the vegetable kingdom. However, we don’t intend to study ’em,
so let’s forget ’em. Those animals were undoubtedly intelligent beings; they probably are
a race of savages of this satellite.”
“Then the really civilized races are probably . . .”
“Not necessarily — there may well be different types, each struggling toward
civilization. There certainly are on Venus, and there once were on Mars.”
“Why haven’t we seen anything like that before, in all these months ? Things
have been so calm and peaceful that we thought we had the whole world to ourselves,
as far as danger or men were concerned.”
“We never saw them before because we never went where they lived—you were
a long ways from your usual stamping-grounds, you know. That animal-vegetable flower
is probably a high-altitude organism, living in the mountains and never coming as low as
we are down here. As for the savages—whatever they are—they probably never come
within five kilometers of the falls. Many primitive peoples think that waterfalls are
inhabited by demons, and maybe these folks are afflicted the same way.”
“We don’t know much about our new world yet, do we?”
“We sure don’t—and I’m not particularly keen on finding out much more about it
until we get, organized for trouble, either. Well, here we are—just like getting back home
to see the Hope, isn’t it?”
“It if home, and will be until we get one of our own on Earth,” and after Stevens
had read his meters, learning with satisfaction that the full current was still flowing into
the accumulators, he began to cut up the meat.
“Now that you’ve got the power-plant running at last, what next?” asked Nadia,
piling the cuts in the freezer.
“Brandon’s ultra-radio comes next, but it’s got more angles to it than a cubist’s
picture of a set of prisms; so many that I don’t know where to begin. There, that job’s
done— let’s sit down and I’ll talk at you a while. Maybe between us we can figure out
where to start. I’ve got everything to build it lined up except for the tube, but that’s got
me stopped cold. You see, fields of force are all right in most places, but I’ve got to have
one tube, and it’s got to have the hardest possible vacuum. That means a mercury-
vapor super-pump. Mercury is absolutely the only thing that will do the trick and mercury
is one thing that is conspicuous by its absence in these parts. So are tungsten for
filaments, tantalum for plates, and platinum for leads; and I haven’t found anything that I
can use as a getter, either — a metal, you know, to flash inside the tube to clean up the
last traces of atmosphere in it.”
“I didn’t suppose that such a simple thing as a radio tube could hold you up, after
the perfectly unbelievable things that you have done already—but I see now how it
could. Of course the tubes in our receiver over there are too small ?”
“Yes, they are only receiver and communicator tubes, and I need a high-power
transmitting tube—a fifty-kilowatter, at least. I’d give my left leg to the knee joint for one
of those big water-cooled, sixty-kilowatt ten-nineteens right now—it’d save us a lot of
grief.”
“Maybe you could break up those tubes and use the plates and so on?”
“I thought of that, but it won’t work—there isn’t half enough metal in the lot, and
the filaments in particular are so tiny that I couldn’t possibly work them over into a big
one. Then, too, we haven’t got many spare tubes, and if I smash the ones we’re using I
put our communicators out of business for good, so that we can’t yell for help if we have
to drift home—and I still don’t get any mercury.”
“Do you mean to tell me there’s no mercury on this whole planet?”
“Not exactly; but I do mean that I haven’t been able to find any, and that it’s
probably darned scarce. And since all the other metals I want worst are also very dense
and of high atomic weight, they’re probably mighty scarce here, too. Why ? Because
we’re on a satellite, and no matter what hypothesis you accept for the origin of satellites,
you come to the same conclusion—that heavy metals are either absent or most awfully
scarce and buried deep down toward the center. There are lots of heavy metals in
Jupiter somewhere, but we probably couldn’t find them. Jupiter’s atmosphere is one
mass of fog, and we couldn’t see, since we haven’t got an infra-red transformer. I could
build one, in time, but it’d take quite a while—and we couldn’t work on Jupiter, anyway,
because of its gravity and probably because of its atmosphere. And even if we could
work there, we don’t want to spend the rest of our lives prospecting for mercury.”
Stevens fell silent, brow wrinkled in thought.
“You mean, dear, that we’re . . .” Nadia broke off, the sentence unfinished.
“Gosh, no! There’s lots of things not tried yet, and we can always set out to drift
it. I was thinking only of building the tube. And I’m trying to think . . . say, Nadia, what do
you know about Cantrell’s Comet ?”
“Not a thing, except that I remember reading in the newspapers that it was
peculiar for something or other. But what has Cantrell’s Comet got to do with the high
cost of living—or with radio tubes? Have you gone nuts all of a sudden?”
“You’d be surprised!” Stevens grinned at her puzzled expression. “Cantrell’s
Comet is one of Jupiter’s comet family, and is peculiar in being the most massive one
known to science. It was hardly known until after they built that thousand-foot reflector
on the Moon, where the seeing is always perfect, but it has been studied a lot since
then. Its nucleus is small, but extremely heavy—it seems to have an average density of
somewhere around sixteen. There’s platinum and everything else that’s heavy there,
girl. They ought to be there in such quantity that even such a volunteer chemist as I am