She utterly ignored the point. “Then that is all they are interested in? They’re pilgrims and they think the sun is Mecca. Mecca. “

“More or less,” he said, with the emphasis on “less.”

“Then they won’t want to talk to me-or any of us. You’re the one who knows the sun. Is that correct?” She jotted a note on a pad, shaking her elbow briskly.

“Reynolds,” she said, looking up from her pad, “I sure as hell hope you know what you’re doing.”

He said, “Why?”

She did not bother to attempt to disguise her contempt. Few of them did any more and especially not Kelly. It was her opinion that Reynolds should not be here at all. Put him in a rest home back on Earth, she would say. The other astronauts-they were considerate enough to retire when life got too complicated for them. What makes this one man, Bradley Reynolds, why is he so special? All right-she would admit-ten years, twenty years ago, he was a great brave man struggling to conquer the unknown. When I was sixteen years old, I couldn’t walk a dozen feet without tripping over his name or face. But what about now? What is he? I’ll tell you what he is: a broken-down, wrinkled relic of an old man. So what if he’s an astronomer as well as an astronaut? So what if he’s the best possible man for the Lunar observatory? I still say he’s more trouble than he’s worth. He walks around the moon base like a dog having a dream. Nobody can communicate with him. He hasn’t attended a single psychological expansion session since he’s been here, and that goes back well before my time. He’s a morale problem; nobody can stand the sight of him any more. And, as far as doing his job goes, he does it, yes-but that’s all. His heart isn’t in it. Look, he didn’t even know about the aliens being in orbit until I called him in and told him they wanted to see him.

That last part was not true, of course. Reynolds, like everyone, had known about the aliens, but he did have to admit that their approach had not overly concerned him. He had not shared the hysteria which had gripped the whole of the Earth when the announcement was made that an alien starship had entered the system. The authorities had known about it for months before ever releasing the news. By the time anything was said publicly, it had been clearly determined that the aliens offered Earth no clear or present danger. But that was about all anyone had learned. Then the starship had gone into orbit around the moon, an action intended to confirm their lack of harmful intent toward Earth, and the entire problem had landed with a thud in Kelly’s lap. The aliens said they wanted to meet a man who knew something about the sun, and that had turned out to be Reynolds. Then-and only then-had he had a real reason to become interested in the aliens. That day, for the first time in a half-dozen years, he had actually listened to the daily news broadcasts from Earth. He discovered-and it didn’t particularly surprise him-that everyone else had long since got over their initial interest in the aliens. He gathered that war was brewing again. In Africa this time, which was a change in place if not in substance. The aliens were mentioned once, about halfway through the program, but Reynolds could tell they were no longer considered real news. A meeting between a representative of the American moon base and the aliens was being arranged, the newscaster said. It would take place aboard the aliens’ ship in orbit around the moon, he added. The name Bradley Reynolds was not mentioned. I wonder if they remember me, he had thought.

“It seems to me that you could get more out of them than some babble about stars being gods,” Kelly said, getting up and pacing around the room, one hand on hip. She shook her head in mock disbelief and the brown curls swirled downward, flowing like dark honey in the light gravity.

“Oh, I did,” he said casually.

“What?” There was a rustling of interest in the room.

“A few facts about their planet. Some bits of detail I think fit together. It may even explain their theology.”

“Explain theology with astronomy?” Kelly said sharply. “There’s no mystery to sun worship. It was one of our primitive religions.” A man next to her nodded.

“Not quite. Our star is relatively mild-mannered, as Jonathon would say. And our planet has a nice, comfortable orbit, nearly circular.”

“Theirs doesn’t?”

“No. The planet has a pronounced axial inclination, too, nothing ordinary like Earth’s twenty-three degrees. Their world must be tilted at forty degrees or so to give the effects Jonathon mentioned. “

“Hot summers?” one of the men he didn’t know said, and Reynolds looked up in mild surprise. So the underlings were not just spear-carriers, as he had thought. Well enough.

“Right. The axial tilt causes each hemisphere to alternately slant toward and then away from their star. They have colder winters and hotter summers than we do. But there’s something more, as far as I can figure it out. Jonathon says its world ‘does not move in the perfect path’ and that ours, on the other hand, very nearly does.”

“Perfect path?” Kelly said, frowning. “An eight-fold way? The path of enlightenment?”

“More theology,” said the man who had spoken.

“Not quite,” Reynolds said. “Pythagoras believed the circle was a perfect form, the most beautiful of all figures. I don’t see why Jonathon shouldn’t. “

“Astronomical bodies look like circles. Pythagoras could see the moon,” Kelly said.

“And the sun,” Reynolds said.” I don’t know whether Jonathon’s world has a moon or not. But they can see their star, and in profile it’s a circle.”

“So a circular orbit is a perfect orbit.”

“Q.E.D. Jonathon says its planet doesn’t have one, though.”

“It’s an ellipse.”

“A very eccentric ellipse. That’s my guess, anyway. Jonathon used the terms `path-summer’ and `pole-summer,’ so they do distinguish between the two effects.”

“I don’t get it,” the man said.

“An ellipse alone gives alternate summers and winters, but in both hemispheres at the same time,” Kelly said brusquely, her mouth turning slightly downward. “A `pole-summer’ must be the kind Earth has.”

“Oh,” the man said weakly.

“You left out the `great-summer,’ my dear,” Reynolds said with a thin smile.

“What’s that?” Kelly said carefully.

“When the `pole-summer’ coincides with the `path-summer’-which it will, every so often. I wouldn’t want to be around when that happens. Evidently neither do the members of Jonathon’s race.”

“How do they get away?” Kelly said intently.

“Migrate. One hemisphere is having a barely tolerable summer while the other is being fried alive, so they go there. The whole race.”

“Nomads,” Kelly said. “An entire culture born with a pack on its back,” she said distantly. Reynolds raised an eyebrow. It was the first time he had ever heard her say anything that wasn’t crisp, efficient and uninteresting.

“I think that’s why they’re grazing animals, to make it easy even necessary-to keep on the move. A `great-summer’ wilts all the vegetation; a `great-winter’-they must have those, too freezes a continent solid.”

“God,” Kelly said quietly.

“Jonathon mentioned huge storms, winds that knocked it down, sand that buried it overnight in dunes. The drastic changes in the climate must stir up hurricanes and tornadoes.”

“Which they have to migrate through,” Kelly said. Reynolds noticed that the room was strangely quiet.

“Jonathon seems to have been born on one of the Treks. They don’t have much shelter because of the winds and the winters that erode away the rock. It must be hard to build up any sort of technology in an environment like that. I suppose it’s pretty inevitable that they turned out to believe in astrology. “

“What?” Kelly said, surprised.

“Of course.” Reynolds looked at her, completely deadpan. “What else should I call it? With such a premium on reading the stars correctly, so that they know the precise time of year and when the next `great-summer’ is coming-what else would they believe in? Astrology would be the obvious, unchallengeable religion-because it worked!” Reynolds smiled to himself, imagining a flock of atheist giraffes vainly fighting their way through a sandstorm.