“By the time he left, though, we had changed our ideas about the practical importance of studying the Kermel Objects. We decided that it is central to the future of the human species. We have continued his work, but without much of his data base. Take a look at this.”

Judith Niles projected another scene onto the display. “Does it seem familiar?” Sy studied it for a second or two, then shrugged. “It’s a picture of a spiral galaxy, looking down on the disk. I’ve no idea which one.”

“Correct. There’s no way you’d recognize it, but it’s this galaxy, seen from outside. That signal was recorded by Otto Kermel, from one of the Objects sitting way up above the galactic plane. And as part of the same signal, this image came with it.” At her keyed command, another picture overlaid the first one. It was the same galaxy, but now the star patterns were shown in different colors. “Keep watching closely. I’m going to zoom.”

The star fields expanded steadily as the field of view moved in to focus on one of the spiral arms. Soon individual stars could be distinguished on the screen. Judith Niles halted the zoom and moved the image to occupy one quadrant of the display. “Once you look at particular stars, you can see what’s going on. The stars in this image have been color-coded according to spectral type. And by looking at the stars in our own stellar neighborhood, it was easy for us to read the code. For instance, Sol is a G-2 V dwarf, and G-types show in pale green. Red giants are magenta, O-type supergiants are purple, and red dwarf stars are shown as orange-yellow.

“There is another important piece of information in this display. Stars don’t sit in fixed positions, they move relative to each other. So by looking at the configuration of stars in the main stellar clusters, you can determine the date of an image. All the evidence was consistent, and told us that this image represented the situation as it was nine hundred thousand Earth-years ago. When Otto Kermel received another signal of the same type, he thought at first that it was just a copy. But it wasn’t. Here it is.”

She brought another image on the screen, placing it in a second quadrant of the display. “For one thing, you can see that the star positions are different. This shows the stellar distribution at a different date. It is still our local arm of the galaxy, but as it was six hundred thousand Earth-years ago. Now watch closely.”

Yet another image appeared in a third quadrant.

“Here’s one which we date at a hundred and fifty thousand years ago. Take a good look at all three — they are the most important pictures in human history.” Sy stared at the screen in silence for a couple of minutes. “Can you display the color key for spectral type again?” he said at last.

Without speaking, Judith Niles flashed a color code onto the screen header. Sy was silent for an even longer period.

“Where’s Sol?” he finally asked.

Judith Niles smiled grimly, and moved the screen cursor to indicate a green star in the field. “That’s Sol, as it was a hundred and fifty thousand years ago; just as it has been for the past few billion years, and as it is today, and as it ought to be a billion years from now.”

Sy nodded. “It hasn’t changed. But you can see there have been changes in the spectral types of other stars. Far too many of them, and far too fast. Stellar evolution is a very slow process.”

“Exactly. And all the changes have been taking place in one direction. I only showed you the situation for three different times, but we have others. We can use them to extrapolate forward. Here” — a new image occupied the final quadrant of the display — “is the local spiral arm, as our projection says it will be a million years from now.”

She moved the cursor to a point of orange-yellow. “And that is Sol.” “But the color code is for a red dwarf star!”

“That’s right. And that’s why we — and you — are here in Gulf City.”

Sy was studying the images. “Red dwarfs. The whole spiral arm is full of red dwarf stars — far too high a proportion of them.” He looked at each image in turn. “This is impossible. There’s no way that stellar types could change so much, and in such a short time. You must be misinterpreting the data.”

“That’s what we thought — at first. Then we began to compare recent star catalogs with ones made in the earliest days of stellar astronomy. There’s no mistake. The main sequence stars in our spiral have been changing. Randomly, with no pattern that we can see, but what used to be spectral classes G and K are becoming class M. We can’t tell when a particular star is likely to change — that’s a guess we made about the future of Sol — but in general — “ “No way!” Sy shook his head vigorously. “Not unless all the astrophysics I learned back on Pentecost is nonsense. It takes hundreds of millions of years at least for a stable star to move from one spectral class to another.” “You know the same astrophysics as we do. And we can only think of one mechanism for change. Class G and class K stars have surface temperatures between about four and six thousand degrees. Class M are more like two to three thousand. You could get those changes in stellar type for dwarf stars, if somehow you could damp the fusion reaction inside them. Lower the internal energy production, and you would lower the overall temperature.”

Sy looked frustrated. “Maybe. But can you suggest any process that could possibly do that? I know of none.”

“Nor do we. No natural process. That keeps leading us to one unpleasant conclusion. The information we’ve received from the Kermel Objects is true — we’ve done other checks on changes in stellar types. And there’s no natural way for these changes to happen. So: some other entity, living in our spiral arm of the galaxy, prefers stars of lower temperature and luminosity.”

“You mean something or someone is inducing reduced fusion reactions through the spiral arm — intentionally.”

“I mean exactly that.” Judith Niles’ forehead filled with frown lines, and she looked a dozen years older. “It’s a frightening conclusion, but it’s the only one. I don’t think the Kermel Objects are doing this, even though they seem to know a lot about it. We have some evidence that suggests they understand the whole process, and they certainly seem able to predict the rate of change in the spiral arm. But I believe the action doesn’t originate with them. What we’re seeing is the work of another species, one more like ourselves — one that has no use for the deep space preferred by Gossameres or Kermel Objects. These other creatures want to live near a star. A red, low luminosity star.”

She cleared the display, leaned back, and closed her eyes. “A long time ago humans talked of terraforming Mars and Venus, but we never did it. Just too busy blowing ourselves up, I guess, ever to get round to it. Now maybe we’ve met someone more rational and more ambitious than we were. What we are seeing is stellarforming. If it goes on, and if we don’t understand it and find out how to stop it, in another million years this whole spiral arm will have few G-type stars. That will mean the end of human planetary colonies. Eventually, that will be the end of humans. Finis.”

Judith Niles paused. She switched off all the displays.

“We think the Kermel Objects hold the key,” she said softly. “Now do you see why we’re living out here in the middle of nowhere, and why S-space and T-state are so important? In normal space, a million years used to seem like forever. But I expect to be alive, ten thousand Earth-centuries from now.”

Sy wore an expression that Peron and Elissa would have found unfamiliar. He seemed uneasy, and lacking in confidence. “I read it wrong. I thought the reason for being here in Gulf City was safety from outside interference, and control of S-space. The whole advantage of being an ‘Immortal’ was presented to us as increased subjective life span — but now I wonder about that.”