Dyson thought that any intelligent species would be capable of converting its home world into such a sphere within two or three thousand years after it entered the industrial age. So we ought to be able to do it about 4000 A.D. However, it must be a tougher trick in practice than in theory, if the Mirt Korp Ahm, whom we know were at the stage of galactic travel 1.1 billion years ago, waited until a mere thirteen million years ago to do it. Or did they just not bother to get around to it any earlier?

A Dyson sphere would not, of course, show up on optical telescopes, since all of the sun’s light output is trapped inside the sphere. That explains Dihn Ruuu’s failure to see the star when he looked for it in the sky. Nevertheless, even a Dyson-sphere civilization would be unable to make use of all the energy that was available to it, and would have to get rid of some of it in the form of heat, that is to say, infrared radiation. Dyson suggested that the sphere would have a surface temperature of 200° to 300° K., and would be emitting plentiful radiation in the far infrared wavelengths. This, of course, could be detected easily by outside observers. Dihn Ruuu could stop grieving, then. The home star of his creators had neither burned out nor blown up. It was still there — under wraps, so to speak.

Small surprises eclipse big miracles. Old Paradoxian proverb, just invented by your humble servant. Dihn Ruuu had thrown so much astonishing news at us in a dozen sentences that for a moment, in the excitement of the Dyson-sphere discussion, we forgot to get excited over the real orbit-smasher, which was…

That the High Ones possibly weren’t extinct at all…

And that Dihn Ruuu was inviting us to help him pay a call on them.

Wonders were multiplying too swiftly.

Of course, Dihn Ruuu’s guess that the High Ones were still alive was only a guess. The McBurney IV robots had heard neither beep nor plink from the Mirt Korp Ahm in thirteen million years, and it’s dangerous to think of thirteen million years as anything but a zog of a long time. On the other hand, we were accustomed to thinking of the High Ones as beings buried a billion years in the past; if they had survived until thirteen million years ago, it was a reasonable bet that they still existed. On the third hand —

We did a lot of talking all at once, shouting out theories, disputations, suppositions, postulates, hypotheses, and even some plain old guesses. Nobody could hear anybody else in the uproar, until suddenly one voice cut across all the rest:

“Help!”

We fell silent and looked around.

“Who called for help?” Dr. Schein asked.

“I did,” Pilazinool said in a small voice. “I finally did it.”

He finally had. During our excited outburst, the Shilamakka had given way to his old nervous habit of unfastening hands and feet and limbs, and this time, in a kind of supreme act of self-mutilation, he had contrived to unscrew everything at once, arms and legs. Don’t ask me how. I guess he was simultaneously unscrewing his right arm with his left, and his left with his right; however it happened, he had stripped himself down to a bare torso and was looking piteously at his heap of discarded limbs, unable to start assembling himself again. His expression of bewilderment was so intense that I was afraid something was seriously wrong. But then Dr. Schein began to laugh, and Mirrik snorted, and Kelly picked up one of Pilazinool’s arms and put it in place, whereupon Pilazinool began hastily and in huge embarrassment to get the rest of himself attached.

The interruption was just what we needed. We were calm again.

Dr. Schein said quietly, “Dihn Ruuu asks us to follow him to the planet of the High Ones. I’ll call for a vote. All in favor — ?”

Guess how that vote turned out.

But certain practical difficulties keep us from blasting off at once for Mirt, which is what the home world of the High Ones is called. Such as the fact that Mirt is seventy-eight light-years from McBurney IV, and the only transportation available to us at the moment is Nick Ludwig’s ship, which can’t travel at ultradrive speeds. If we set out tomorrow for Mirt in Nick’s ship, I’d celebrate my hundredth birthday before we got there.

So we have to go through the cumbersome business of waiting for our ultradrive cruiser to come back this way on the prearranged checkup flight. That’ll be a month from now. And then to charter a flight to Mirt, if we have the stash to swing it.

Actually, that isn’t too bad. It gives us some time to explore McBurney IV before we rush off to the next wonderworld. It’s unhealthy to gulp down a surfeit of miracles; gives one indigestion of the imagination. Whole careers could be spent just in this one place. Not archaeological careers, I suppose; the story of the High Ones has exploded out of archaeology now. But McBurney IV holds a million times as much to dazzle us as did the cave on the asteroid in the 1145591 system; and we thought that was a high-spectrum load!

The robots here have been very cooperative. Dihn Ruuu explained to them that we were stranded here until our ultraspace ship picked us up, and they accepted that. Whereupon we became honored guests and tourists, instead of prisoners. For the past week we’ve been using the ship as our base, and taking off each day on a sightseeing trip through the Mirt Korp Ahm’s outpost here.

It’s clear now why this place is so different, architecturally, from what we saw in our globe. The cities shown by the globe were a billion years old. McBurney IV was still inhabited by the Mirt Korp Ahm less than a hundred million years ago. Even among so conservative a race as the High Ones, architectural styles do change in hundreds of millions of years. Dangling cities went out of fashion here.

We are only skimming the surface of this world of course. Hairy primitives that we are, we can hardly begin to understand what we see. The power accumulators, draining energy from McBurney’s Star and socking it away underground. The master brain centers that run the transit systems. The automatic repair mechanisms that come scuttling out to fix any mechanical difficulty instantly. The great scanners that tirelessly search the sky for a hint of a signal from the Mirt Korp Ahm — a signal that never comes, alas! The robots themselves, the Dihn Ruuu, self-lubricating, self-repairing, seemingly immortal. The aircars: do they run on antigravity engines? Everything dazzles and bewilders.

Fantastic as their cities are, though, the Mirt Korp Ahm aren’t really a billion years ahead of us in technological development. Considering the head start they had, the High Ones actually seem a little backward, as though consciously or otherwise they froze their culture at this level long ago. I mean, this super-civilization of theirs is just about what I’d expect Earth to have in, say, the year 10,000, if I projected our technological growth forward on the same curve as it’s been following since about A.D. 1700. But it’s not what I’d expect Earth to have in the year 1,000,-002,376. Not by plenty.

I don’t think I can even imagine what a culture that’s been developing steadily for a billion years ought to be like. Disembodied electrical essences, maybe. Ghostly creatures flitting in and out of the eighth, ninth, and tenth dimensions. Cosmic minds that know all, perceive all, understand all.

Maybe I’m being unfair to the Mirt Korp Ahm. Perhaps the growth curve of our technology in the years 1700-2300 was wildly atypical; perhaps the growth curve of any civilization inevitably flattens out once it reaches a certain level. I can’t help feeling that the Mirt Korp Ahm should have gone farther than they did, with all the time they had to evolve, but possibly they bucked up against the absolute limits of ingenuity and went static. Possibly the same thing will happen to us, two or three thousand years up the line. I wonder.