"They know their stuff, all right--you've got to hand it to 'em. I've been straightening out that brain record--cutting out the hazy stretches and getting his knowledge straightened out so we can use it, and there's a lot of this kind of stuff in the record you can get. Suppose that you can figure out exactly where he comes from with this dope and with his brain record?"

"Certainly. I may be able to get more complete information upon the green system than the Osnomians have, which will be very useful indeed.

You are right--I am intensely interested in this material, and if you do not care particularly about studying it any more at this time, I believe that I should begin to study it now."

"Hop to it. I'm going to study that record some more. No human brain can take it all, I'm afraid, especially all at once, but I'm going to kinda peck around the edges and get me some dope that I want pretty badly. We got a lot of stuff from that wampus."

About sixty hours out, Dorothy, who had been observing the planet through number six visiplate, called Seaton away from the Fenachrone brain-record, upon which he was still concentrating.

"Come here a minute, d.i.c.kie! Haven't you got that knowledge all packed away in your skull yet?"

"I'll say I haven't. That bird's brain would make a dozen of mine, and it was loaded until the scuppers were awash. I'm just nibbling around the edges yet."

"I've always heard that the capacity of even the human brain was almost infinite. Isn't that true?" asked Margaret.

"Maybe it is, if the knowledge were built up gradually over generations.

I think maybe I can get most of this stuff into my peanut brain so I can use it, but it's going to be an awful job."

"Is their brain really as far ahead of ours as I gathered from what I saw of it?" asked Crane.

"It sure is," replied Seaton, "as far as knowledge and intelligence are concerned, but they have nothing else in common with us. They don't belong to the genus 'h.o.m.o' at all, really. Instead of having a common ancestor with the anthropoids, as they say we had, they evolved from a genus which combined the worst traits of the cat tribe and the carnivorous lizards--the most savage and bloodthirsty branches of the animal kingdom--and instead of getting better as they went along, they got worse, in that respect at least. But they sure do know something.

When you get a month or so to spare, you want to put on this harness and grab his knowledge, being very careful to steer clear of his mental traits and so on. Then, when we get back to the Earth, we'll simply tear it apart and rebuild it. You'll know what I mean when you get this stuff transplanted into your own skull. But to cut out the lecture, what's on your mind, Dottie Dimple?"

"This planet Martin picked out is all wet, literally. The visibility is fine--very few clouds--but this whole half of it is solid ocean. If there are any islands, even, they're mighty small."

All four looked into the receiver. With the great magnification employed, the planet almost filled the visiplate. There were a few fleecy wisps of cloud, but the entire surface upon which they gazed was one sheet of the now familiar deep and glorious blue peculiar to the waters of that cuprous solar system, with no markings whatever.

"What d'you make of it, Mart? That's water all right--copper-sulphate solution, just like the Osnomian and Urvanian oceans--and nothing else visible. How big would an island have to be for us to see it from here?"

"So much depends upon the contour and nature of the island, that it is hard to say. If it were low and heavily covered with their green-blue vegetation, we might not be able to see even a rather large one, whereas if it were hilly and bare, we could probably see one only a few miles in diameter."

"Well, one good thing, anyway, we're approaching it from the central sun, and almost in line with their own sun, so it's daylight all over it. As it turns and as we get closer, we'll see what we can see. Better take turns watching it, hadn't we?" asked Seaton.

It was decided, and while the _Skylark_ was still some distance away, several small islands became visible, and the period of rotation of the planet was determined to be in the neighborhood of fifty hours.

Margaret, then at the controls, picked out the largest island visible and directed the bar toward it. As they dropped down close to their objective, they found that the air was of the same composition as that of Osnome, but had a pressure of seventy-eight centimeters of mercury, and that the surface gravity of the planet was ninety-five hundredths that of the Earth.

"Fine business!" exulted Seaton. "Just about like home, but I don't see much of any place to land without getting wet, do you? Those reflectors are probably solar generators, and they cover the whole island except for that lagoon right under us."

The island, perhaps ten miles long and half that in width, was entirely covered with great parabolic reflectors, arranged so closely together that little could be seen between them. Each reflector apparently focussed upon an object in the center, a helix which seemed to writhe luridly in that flaming focus, glowing with a nacreous, opalescent green light.

"Well, nothing much to see there--let's go down," remarked Seaton as he shot the _Skylark_ over to the edge of the island and down to the surface of the water. But here again nothing was to be seen of the land itself. The wall was one vertical plate of seamless metal, supporting huge metal guides, between which floated metal pontoons. From these gigantic floats metal girders and trusses went through slots in the wall into the darkness of the interior. Close scrutiny revealed that the large floats were rising steadily, although very slowly; while smaller floats bobbed up and down upon each pa.s.sing wave.

"Solar generators, tide-motors, and wave-motors, all at once!"

e.j.a.c.u.l.a.t.ed Seaton. "_Some_ power-plant! Folks, I'm going to take a look at that if I have to drill in with a ray!"

[Ill.u.s.tration: Some power plant! Folks, I'm going to take a look at that....]

They circ.u.mnavigated the island without revealing any door or other opening--the entire thirty miles was one stupendous battery of the generators. Back at the starting point, the _Skylark_ hopped over the structure and down to the surface of the small central lagoon previously noticed. Close to the water, it was seen that there was plenty of room for the vessel to move about beneath the roof of reflectors, and that the island was one solid stand of tide-motors. At one end of the lagoon was an open metal structure, the only building visible, and Seaton brought the s.p.a.ce-cruiser up to it and through the huge opening--for door there was none. The interior of the room was lighted by long, tubular lights running around in front of the walls, which were veritable switchboards. Row after row and tier upon tier stood the instruments, plainly electrical meters of enormous capacity and equally plainly in full operation, but no wiring or bus-bar could be seen.

Before each row of instruments there was a narrow walk, with steps leading down into the water of the lagoon. Every part of the great room was plainly visible, and not a living being was even watching that vast instrument-board.

"What do you make of it, d.i.c.k?" asked Crane, slowly.

"No wiring--tight beam transmission. The Fenachrone do it with two matched-frequency separable units. Millions and millions of kilowatts there, if I'm any judge. Absolutely automatic too, or else----" Seaton's voice died away.

"Or else what?" asked Dorothy.

"Just a hunch. I wouldn't wonder if----"

"Hold it, d.i.c.ky! Remember I had to put you to bed after that last hunch you had!"

"Here it is, anyway. Mart, what would be the logical line of evolution when the planet has become so old that all the land has been eroded to a level below that of the ocean? You picked us out an old one, all right--so old that there's no land left. Would a highly civilized people revert to fish? That seems like a backward move to me, but what other answer is possible?"

"Probably not to true fishes--although they might easily develop some fish-like traits. I do not believe, however, that they would go back to gills or to cold blood."

"What _are_ you two saying?" interrupted Margaret. "Do you mean to say that you think _fish_ live here instead of people, and that _fish_ did all this?" as she waved her hand at the complicated machinery about them.

"Not fish exactly, no." Crane paused in thought. "Merely a people who have adjusted themselves to their environment through conscious or natural selection. We had a talk about this very thing in our first trip, shortly after I met you. Remember? I commented on the fact that there must be life throughout the Universe, much of it that we could not understand; and you replied that there would be no reason to suppose them awful because incomprehensible. That may be the case here."

"Well, I'm going to find out," declared Seaton, as he appeared with a box full of coils, tubes, and other apparatus.

"How?" asked Dorothy, curiously.

"Fix me up a detector and follow up one of those beams. Find its frequency and direction, first, you know, then pick it up outside and follow it to where it's going. It'll go through anything, of course, but I can trap off enough of it to follow it, even if it's tight enough to choke itself," said Seaton.

"That's one thing I got from that brain record."

He worked deftly and rapidly, and soon was rewarded by a flaring crimson color in his detector when it was located in one certain position in front of one of the meters. Noting the bearing on the great circles, he then moved the _Skylark_ along that exact line, over the reflectors, and out beyond the island, where he allowed the vessel to settle directly downwards.

"Now folks, if I've done this just right, we'll get a red flash directly."

As he spoke the detector again burst into crimson light, and he set the bar into the line and applied a little power, keeping the light at its reddest while the other three looked on in fascinated interest.

"This beam is on something that's moving, Mart--can't take my eyes off it for a second or I'll lose it entirely. See where we're going, will you?"

"We are about to strike the water," replied Crane quietly.

"The water!" exclaimed Margaret.

"Fair enough--why not?"

"Oh, that's right--I forgot that the _Skylark_ is as good a submarine as she is an airship."

Crane pointed number six visiplate directly into the line of flight and started into the dark water.

"Mow deep are we, Mart?" asked Seaton after a time.