Long-distance travel through a planetary atmosphere was not something that Settlers accepted as part of their society. On a Settlement, distances were small enough so that elevators, legs, and an occasional electric cart were all that was necessary. As for inter-Settlement travel, that was by rocket.

Many Settlers - at least, back in the Solar System - had been in space so many times that progress through it was almost as common to them as walking. It was a rare Settler, however, who had traveled to Earth, where alone atmospheric travel existed, and which had made use of airflight.

Settlers who could face the vacuum as though it were a friend and brother felt unfathomable terror if expected to sense, somehow, the whistle of air past a vehicle without ground-support below.

Yet air travel, on occasion, was an obvious necessity on Erythro. Like Earth it was a large world, and like Earth it had a fairly dense (and breathable) atmosphere. There were reference books on airflight available on Rotor, and even several Earth immigrants with aeronautical experience.

So the Dome owned two small aircraft, somewhat clumsy, somewhat primitive, ungiven to large bursts of speed, or to headlong maneuverability - but serviceable. In fact, Rotor's very ignorance of aeronautical engineering helped in one respect. The Dome's aircraft were far more computerized than any corresponding vessel on Earth. In fact, Siever Genarr liked to think of the vessels as intricate robots that happened to be built in the shape of aircraft. Erythro's weather was much milder than Earth's could possibly be, since the low intensity of the radiation from Nemesis was insufficient to power large and violent storms, so that an aircraft-robot was less likely to have to face an emergency. Far less likely.

As a result, virtually anyone could fly the raw and unpolished aircraft of the Dome. You simply told the plane what you wanted it to do and it was done. If the message was unclear, or seemed dangerous to the robotic brain of the vessel, it asked for clarification.

Genarr watched Marlene climb into the cabin of the plane with a certain natural concern, if not with the lip-biting terror of Eugenia Insigna, who stood well away from the scene. (‘Don't come any closer,’ he had ordered Insigna sternly, ‘especially if you're going to look as though you were witnessing the sure beginning of calamity. You'll panic the girl.’)

It seemed to Insigna that there were grounds for panic. Marlene was too young to remember a world where air-flight was common. She had taken a rocket calmly enough to come to Erythro, but how would she react to this unheard of flight through air?

And yet Marlene climbed into the cabin and took her seat with a look of utter calm on her face.

Was it possible she did not grasp the situation? Genarr said, ‘Marlene, dear, you do know what we're going to be doing, don't you?’

‘Yes, Uncle Siever. You're going to show me Erythro.’

‘From the air, you know. You'll be flying through the air.’

‘Yes. You said so before.’

‘Does the thought of it bother you?’

‘No, Uncle Siever, but it's bothering you a lot.’

‘Only on your behalf, dear.’

‘I'll be perfectly all right.’ She turned her calm face toward him as he climbed in after her and took his seat. She said, ‘I can understand Mother being concerned, but you're more concerned than she is. You're managing to show it less in any big way, but if you could see yourself licking your lips, you would be embarrassed. You feel that if something bad happens, it will be your fault, and you just can't stand the thought. Just the same, nothing's going to happen.’

‘Are you sure of that, Marlene?’

‘Absolutely sure. Nothing will harm me on Erythro.’

‘You said that about the Plague, but we're not talking about that now.’

‘It doesn't matter what we're talking about. Nothing will harm me on Erythro.’

Genarr shook his head slightly in disbelief and uncertainty, and then wished he hadn't, for he knew she read that as easily as though it were appearing in the largest block letters on the computer screen. But what was the difference? If he had repressed it all and had acted as if he were made of cast bronze, she would still have seen it.

He said, ‘We'll go into an airlock and stay there just a while, so that I can check the responsiveness of the vessel's brain. Then we will go through another door and the plane will then move up in the air. There'll be an acceleration effect, and you'll be pressed backward, and we'll be moving in the air, with nothing beneath us. You understand that, I hope?’

‘I am not afraid,’ said Marlene quietly.

The aircraft remained on its steady course across a barren landscape of rolling hills.

Genarr knew that Erythro was geologically alive and knew also that what geological studies had been made of the world indicated that there had been periods in its history when it had been mountainous. And there were still mountains here and there on the cis-Megan hemisphere, the hemisphere in which the bloated circle of the planet Megas, around which Erythro orbited, hung almost motionless in the sky.

Here on the trans-Megan side, however, plains and hills were the chief feature of the two large continents.

To Marlene, who had never seen a mountain in her life, even the low hills were exciting.

There were rivulets on Rotor, of course, and from the height at which they were viewing Erythro, these rivers looked no different.

Genarr thought: Marlene will be surprised when she sees them at a closer view.

Marlene look curiously at Nemesis, which had passed its noonmark and had declined toward the west. She said, ‘It's not moving, is it, Uncle Siever?’

‘It's moving,’ said Genarr. ‘Or, at least Erythro is turning relative to Nemesis, but it turns only once a day, while Rotor turns once every two minutes. In comparison, Nemesis, as seen from here on Erythro, is moving less than 1/700th as fast as it seems to be moving as seen from Rotor. It seems to be standing still here, by comparison, but it isn't standing entirely still.’

Then, casting a quick glance at Nemesis, he said, ‘You've never seen Earth's Sun, the Sun of the Solar System, you know; or, if you have, you don't remember it, having been a baby at the time. The Sun was much smaller as seen from Rotor's position in the Solar System.’

‘Smaller?’ said Marlene in surprise. ‘The computer told me that it was Nemesis that was smaller.’

‘In reality, yes. Still, Rotor is so much closer to Nemesis than it ever was to the Sun in the old days that Nemesis seems larger.’

‘We're four million kilometers from Nemesis, aren't we?’

‘But we were a hundred fifty million kilometers from the Sun. If we were that far from Nemesis, we'd get less than 1 per cent of the light and warmth we get now. If we were as close to the Sun as we are to Nemesis, we'd be vaporized. The Sun is much larger, brighter and hotter than Nemesis.’

Marlene wasn't looking at Genarr, but apparently his tone of voice was sufficient. ‘From the way you talk, Uncle Siever, I think you wish you were back near the Sun.’

‘I was born there, so I get homesick sometimes.’

‘But the Sun is so hot and bright. It must be dangerous.’

‘We didn't look at it. And you shouldn't look at Nemesis too long either. Look away, dear.’

Genarr cast another quick glance at Nemesis, however. It hung in the western sky, red and vast, its apparent diameter at four degrees of arc, or eight times that of the Sun as seen from Rotor's old position. It was a quiet red circle of light, but Genarr knew that, on comparatively rare occasions, it would flare and, for a few minutes, there would be a white spot on that serene face that would be painful to look at. Mild sunspots, in darker red, were more common, but not as noticeable.

He murmured an order to the plane, which veered sufficiently to put Nemesis farther to the rear, out of direct view.

Marlene took a last, thoughtful glance at Nemesis, then turned her eyes to Erythro's vista stretched out below.

She said, ‘You get used to the pink color of everything. It doesn't look so pink after a while.’

Genarr had noticed that himself. His eyes caught differences in tint and shade so that the world began to seem less monochromatic. The rivers and small lakes were ruddier and darker than the land surface, and the sky was dark. Little of the red light of Nemesis was scattered by Erythro's atmosphere.

The most hopeless thing about Erythro, however, was the barrenness of the land. Rotor, even on its tiny scale, had green fields, yellow grain, varicolored fruit, noise-making animals, all the color and sound of human habitation and structures.

Here there was only silence and inanimation.

Marlene frowned. ‘There is life on Erythro, Uncle Siever.’

Genarr couldn't tell whether Marlene was making a statement, asking a question, or answering his thought as revealed by his body language. Was she insisting on something or seeking reassurance?

He said, ‘Certainly. Lots of life. It's all-pervasive. It's not only in the water either. There are prokaryotes living in the water films about the soil particles, too.’

After a while, the ocean made its appearance on the horizon ahead, first as simply a dark line, then a thickening band as the air vehicle approached it.

Genarr cast careful sidelong glances at Marlene, watching her reaction. She had read about Earth's oceans, of course, and must have seen images on holovision, but nothing can prepare anyone for the actual experience. Genarr, who had been on Earth once (once!) as a tourist, had seen the edge of an ocean. He had never been over one, out of sight of land, however, and he wasn't sure of his own reactions.

It rolled back below them and now the dry land shrank behind into a lighter line and, eventually, it was gone. Genarr looked down with a queer feeling in the pit of his stomach. He remembered a phrase from an archaic epic: ‘the wine-dark sea’. Below them the ocean certainly did look like a vast rolling mass of red wine, with pink froth here and there.

There were no markings to identify in that vast body of water, and there was no place to land. The very essence of ‘location’ was gone. Yet he knew that when he wanted to return, he need do no more than direct the plane to take them back to land. The plane's computer kept track of position in accurate reckoning of speed and direction and would know where land was - even where the Dome was.

They passed under a thick cloud deck and the ocean turned black. A word from Genarr, and the plane lifted through and above the clouds. Nemesis shone again, and the ocean could no longer be seen beneath them. There was, instead, a sea of pink water droplets, billowing and rising here and there, so that bits of fog moved, occasionally, past the window.