It was not the best way to make pictures, but Corbell could recognize a man and a woman holding hands... the same figures in each cube. There were polygons of assorted sizes, in rows, and rough spheres. Peerssa created a red arrow for a pointer. "In your opinion, are these intended to represent human beings?"
"Sure."
He indicated the similar figures in the right-hand cube. "And these?"
"Yes."
The arrow returned to the left-hand cube. "This was the first message to arrive. These figures may represent atomss carbon and hydrogen and oxygen. Do you agree?"
"For all of me they do. Why would they be there?"
"They form the basis for protoplasmic chemistry. This bigger row, might it be a solar system? The large, nearly spherical hollow object would be the sun. The symbols inside may be four hydrogen atoms next to a helium atom. The row of smaller polygons would be planets."
"All right. Is it the solar system?"
"Not unless the solar system has changed radically. What about this second cube? Why are these human figures different from the others?"
Corbell looked from one to the other. In the first message the figures were solid, except for hollow bubbles to mark the lungs. The cubistic figures in the second group were hollow, and there was an X of small cubes running through them. "I think I see. They're crossed out in that second message. And those rows of polygons look like eight more stellar systems, suns and planets, drawn smaller. Some double suns."
"What message do you see?"
"Eight star systems, two with double stars. Crossed-out hollow people. All right, read it this way. 'To whom it may concern. We are human, we fit the given model, our chemistry is based on carbon and water. We come from a star system that looks like this. The similar people who come from these eight other systems look human, but they aren't. Accept no substitutes.' Does that sound right?"
"I agree."
"Well, it's a very human thing to say. I could see your precious State sending a message like that, except... except the State didn't have any natural enemies. Everyone belonged to the State. So this is the message you followed home?"
"Yes. I felt that human beings must have sent it, and I was not sure of finding Sol otherwise."
"How did they find us? Whoever sent that beam would have had to find us a couple of hundred light-years out. We were still moving at near light-speed, weren't we?"
"The exhaust from a ramship would be most conspicuous to the right instruments. But the returning beam was very powerful. Sending it required strong motives."
Corbell smiled in evil satisfaction. "The strongest. Heresy. Your State came apart, Peerssa. The colonies revolted. The State around Sol must have wanted to warn any returning starships. Don't stop at the colonies."
"The State was a water-monopoly empire, as you told me. Such entities do not die by internal revolution. They die only by conquest by an outside force."
Corbell laughed. He didn't like the sound: a high-pitched cackle.
"I'm not a history teacher, Peerssa, you idiot! I'm an architect! It was a friend who told me about water-control empires, and he's one of- he was one of these guys who say everything in absolutes because it gets more attention. I never knew how seriously to take him."
"But you believe him."
"Oh, a little, but what empire ever lasted seventy thousand years? If you hadn't taken me so damn seriously, we'd have been home. two million, nine hundred and thirty thousand years ago." Corbell was studying the pattern of the sun and planets in the left-hand cube. "We're in a system that matches that picture?"
"Yes."
There was the sun, then three small objects, then a large object with a conspicuous lump on it (a large moon?), then three medium sized objects. "The Earth isn't there. Otherwise-"
"Do you see the body now rising beyond this world's horizon?" For a split second Corbell thought it was the Moon rising above the world's hazy edge. It was half full. It showed bigger than the Moon. It glowed in white and orange-white bands along the lighted side. What should have been the dark side glowed just at red heat.
Peerssa said, "This oxygen-atmosphere world we circle is in orbit about that larger body. The primary is a massive gas giant, hotter than theory would account for. There are other anomalies in this system."
"We're in orbit about a moon of that thing?"
"I said that, yes."
Corbell's head whirled. "All right, Peerssa. Show me."
Peerssa showed him, with diagrams and with photographs taken during Don Juan's fiery fall through the system.
The sun was a young red giant, swollen and hot: of about one solar mass, but with a diameter of ten million kilometers.
Peerssa showed him the inner planet next to a map of Mercury. Granted the two planets resembled each other, but this system's version was scarred and gouged in a different pattern.
The second planet had considerably less atmosphere than Venus, and what there was included some oxygen. But it was the right size and in the right place.
There was nothing in Earth's orbit.
The third planet remarkably resembled Mars, but for the lack of moons and the great featureless mare marring one face. "There are curious parallels all through the system," Peerssa remarked.
Corbell's reaction to these revelations was a slowly mounting anger. Had he come home or hadn't he? "Right. Curious. What about Earth?"
A moon much like the Earth circled this fourth planet... a world as massive as Jupiter, but far hotter than a world at this distance from its primary ought to be, even given the hotter sun. It was pouring out infrared radiation in enormous quantities, and more dangerous radiation too.
"And the other moons? Their orbits would be funny anyway; they'd have been altered when the Earth was moved into place, if that's Earth."
"I thought of that. But I can find no moon of this world analogous to Ganymede, the biggest of the Jovian moons."
"All right, go on."
The fifth planet was an unknown, an ice giant in a drunken skewed orbit that took it from just inside the Jovian's orbit almost out to the sixth planet's. It was near the Jovian now, naked-eye visible from Don Juan. Peerssa showed him a close view of a marble banded in pale blues.
"This system may be much younger than Sol system," Peerssa said. "The skewed orbit of the fifth planet has not had time to become circular via tidal effects. The Jovian is hot because it only recently condensed from the planetary nebula. The star has not yet settled down to steady burning."
"What about this Earthlike world? Could it have evolved that fast?"
"I didn't think so. And that third planet looked a lot like Mars. But not enough, dammit!"
"Then observe the sixth."
The sixth planet-well, it looked like a target. Don Juan had crossed nearly over the North Pole. Nestled within banded white rings was the fainter banding of an ice-giant planet, in very pale blues and greens. The oval shadow of the planet lay across the rings, rendering the transparent inner ring invisible. The sharp-edged rift must be Cassini's Divide, Corbell thought. He found other, lesser rifts probably caused by tides from smaller moons. "Saturn," he said.
"It resembles Saturn most remarkably. I went to some effort to take our course near this sixth planet. I tried to find discrepancies-"