"Hey, Arcot," Wade said. "I thought you said we wouldn't be able to see the stars."

Arcot spread his hands. "I did say that, and all my apologies for it.

But we're not seeing them by light. The stars all have projections--shadows--in this s.p.a.ce because of their intense gravitational fields. There are probably slight fluctuations in the field, perhaps one every minute or so. Since we were approaching them at twenty thousand times the speed of light, the Doppler effect gives us what looks like violet light.

"We saw the stars in front of us as violet points. The green ones were actually behind us, and the green light was tremendously reduced in frequency. It certainly can't be anything less than gamma rays and probably even of greater frequency.

"Did you notice there were no stars off to the side? We weren't approaching them, so they didn't give either effect."

"How did you know which was which?" asked Fuller skeptically.

"Did you see that green star directly ahead of us?" Arcot asked. "The one that dwindled so rapidly? That could only have been the sun, since the sun was the only star close enough to show up as a disc. Since it was green and I knew it was behind us, I decided that all the green ones were behind us. It isn't proof, but it's a good indication."

"You win, as usual," admitted Fuller.

"Well, where are we?" asked Wade. "I think that's more important."

"I haven't the least idea," confessed Arcot. "Let's see if we can find out. I've got the robot pilot on, so we can leave the ship to itself.

Let's take a look at Old Sol from a distance that no man ever reached before!"

They started for the observatory. Morey joined them and Arcot put the view of Sol and his family on the telectroscope screen. He increased the magnification to maximum, and the four men looked eagerly at the system.

The sun glowed brilliantly, and the planets showed plainly.

"Now, if we wanted to take the trouble, we could calculate when the planets were in that position and determine the distance we have come.

However, I notice that Pluto is still in place, so that means we are seeing the Solar System as it was before the pa.s.sing of the Black Star.

We're at least two light years away."

"More than that," said Morey. He pointed at the screen. "See here, how Mars is placed in relation to Venus and Earth? The planets were in that configuration seven years ago. We're seven light years from Earth."

"Good enough!" Arcot grinned. "That means we're within two light years of Sirius, since we were headed in that direction. Let's turn the ship so we can take a look at it with the telectroscope."

Since the power had been cut off, the ship was in free fall, and the men were weightless. Arcot didn't try to walk toward the control room; he simply pushed against the wall with his feet and made a long, slow dive for his destination.

The others reached for the handgrips in the walls while Arcot swung the ship gently around so that its stern was pointed toward Sirius. Because of its brilliance and relative proximity to Sol, Sirius is the brightest star in the heavens, as seen from Earth. At this much lesser distance, it shone as a brilliant point of light that blazed wonderfully. They turned the telectroscope toward it, but there was little they could see that was not visible from the big observatory on the Moon.

"I think we may as well go nearer," suggested Morey, "and see what we find on close range observation. Meanwhile, turn the ship back around and I'll take some pictures of the sun and its surrounding star field from this distance. Our only way of getting back is going to be this series of pictures, so I think we had best make it complete. For the first light century, we ought to take a picture every ten light years, and after that one each light century until we reach a point where we are only getting diminishing pictures of the local star cl.u.s.ter. After that, we can wait until we reach the edge of the Galaxy."

"Sounds all right to me," agreed Arcot. "After all, you're the astronomer, I'm not. To tell you the truth, I'd have to search a while to find Old Sol again. I can't see just where he is. Of course, I could locate him by means of the gyroscope settings, but I'm afraid I wouldn't find him so easily visually."

"Say! You sure are a fine one to pilot an expedition in s.p.a.ce!" cried Wade in mock horror. "I think we ought to demote him for that! Imagine!

He plans a trip of a thousand million light years, and then gets us out seven light years and says he doesn't know where he is! Doesn't even know where home is! I'm glad we have a cautious man like Morey along."

He shook his head sadly.

They took a series of six plates of the sun, using different magnifications.

"These plates will help prove our story, too," said Morey as he looked at the finished plates. "We might have gone only a little way into s.p.a.ce, up from the plane of the ecliptic and taken plates through a wide angle camera. But we'd have had to go at least seven years into the past to get a picture like this."

The new self-developing short-exposure plates, while not in perfect color balance, were more desirable for this work, since they took less time on exposure.

Morey and the others joined Arcot in the control room and strapped themselves into the cushioned seats. Since the s.p.a.ce strain mechanism had proved itself in the first test, they felt they needed no more observations than they could make from the control room meters.

Arcot gazed out at the spot that was their immediate goal and said slowly: "How much bigger than Sol is that star, Morey?"

"It all depends on how you measure size," Morey replied. "It is two and a half times as heavy, has four times the volume, and radiates twenty-five times as much light. In other words, one hundred million tons of matter disappear each second in that star.

"That's for Sirius A, of course. Sirius B, its companion, is a different matter; it's a white dwarf. It has only one one-hundred-twenty-five-thousandths the volume of Sirius A, but it weighs _one third_ as much. It radiates more per square inch than our sun, but, due to its tiny size, it is very faint. That star, though almost as ma.s.sive as the sun, is only about the size of Earth."

"You sure have those statistics down pat!" said Fuller, laughing. "But I must say they're interesting. What's that star made of, anyway? Solid lux metal?"

"Hardly!" Morey replied. "Lux metal has a density of around 103, while this star has a density so high that one cubic inch of its matter would weigh a ton on Earth."

"Wow!" Wade e.j.a.c.u.l.a.t.ed. "I'd hate to drop a baseball on my toe on that star!"

"It wouldn't hurt you," Arcot said, smiling. "If you could lift the darned thing, you ought to be tough enough to stand dropping it on your toe. Remember, it would weigh about two hundred tons! Think you could handle it?"

"At any rate, here we go. When we get there, you can get out and try it."

Again came the shock of the start. The heavens seemed to reel about them; the bright spot of Sirius was a brilliant violet point that swelled like an expanding balloon, spreading out until it filled a large angle.

Then again the heavens reeled, and they were still. The control room was filled with a dazzling splendor of brilliant blue-white light, and an intense heat beat in upon them.

"Brother! Feel that heat," said Arcot in awe. "We'd better watch ourselves; that thing is giving off plenty of ultraviolet. We could end up with third-degree sunburns if we're not careful." Suddenly he stopped and looked around in surprise. "Hey! Morey! I thought you said this was a double star! Look over there! That's no white dwarf--_it's a planet_!"

"Ridiculous!" snapped Morey. "It's impossible for a planet to be in equilibrium about a double star! But--" He paused, bewildered. "But it is a planet! But--but it can't be! We've made too many measurements on this star to make it possible!"

"I don't give a hang whether it can or not," Wade said coolly, "the fact remains that it is. Looks as if that shoots a whole flock of holes in that bedtime story you were telling us about a superdense star."

"I make a motion we look more closely first," said Fuller, quite logically.

But at first the telectroscope only served to confuse them more. It was most certainly a planet, and they had a strange, vague feeling of having seen it before.

Arcot mentioned this, and Wade launched into a long, pedantic discussion of how the left and right hemispheres of the brain get out of step at times, causing a sensation of having seen a thing before when it was impossible to have seen it previously.

Arcot gave Wade a long, withering stare and then pushed himself into the library without saying a word. A moment later, he was back with a large volume ent.i.tled: "_The Astronomy of the Nigran Invasion_," by _D. K.

Harkness_. He opened the volume to a full-page photograph of the third planet of the Black Star as taken from a s.p.a.ce cruiser circling the planet. Silently, he pointed to it and to the image swimming on the screen of the telectroscope.

"Good Lord!" said Wade in astonished surprise. "It's impossible! We came here faster than light, and that planet got here first!"

"As you so brilliantly remarked a moment ago," Arcot pointed out, "I don't give a hang whether it can or not--it is. How they did it, I don't know, but it does clear up a number of things. According to the records we found, the ancient Nigrans had a force ray that could move planets from their orbits. I wonder if it couldn't be used to break up a double star? Also, we know their scientists were looking for a method of moving faster than light; if we can do it, so could they. They just moved their whole system of planets over here after getting rid of the upsetting influence of the white dwarf."

"Perfect!" exclaimed Morey enthusiastically. "It explains everything."

"Except that we saw that companion star when we stopped back there, half an hour ago," said Fuller.

"Not half an hour ago," Arcot contradicted. "Two years ago. We saw the light that left the companion before it was moved. It's rather like traveling in time."

"If that's so," asked Fuller, suddenly worried, "what is our time in relation to Earth?"

"If we moved by the s.p.a.ce-strain drive at all times," Arcot explained, "we would return at exactly the same time we left. Time is pa.s.sing normally on Earth as it is with us right now, but whenever we use the s.p.a.ce-strain, we move instantaneously from one point to another as far as Earth and the rest of the universe is concerned. It seems to take time to us because we are within the influence of the field.