Three years on Earth had aged Tessa Wendel. Her complexion had coarsened a bit. She had put on some weight. There was the beginning of jowls and dark patches under her eyes. Her breasts had grown a shade pendulous and her waist had thickened.

Crile Fisher knew that Tessa was in her late forties now, that she was five years older than he was. But she did not look older than her years. She was still a fine mature figure of a woman (as he had heard someone refer to her), but she would no longer pass for a woman in her thirties, as she might easily have done when he had first met her at Adelia.

Tessa was aware of it, too, and had spoken of it bitterly to him only the week before.

‘It's you, Crile,’ she had said one night when they were in bed together (a time when, apparently, she was most conscious of aging). ‘The fault is yours. You sold me on Earth. “Magnificent,” you said. “Enormous,” you said. “Variety. Always something new. Inexhaustible.” ’

‘And isn't it?’ he said, knowing what she found objectionable, but willing to let her vent her feelings once again.

‘Not where gravity is concerned. All over this entire bloated, impossible planet, you have the same gravitational pull. Up in the air, down in a mine, here, there, everywhere, one G - one G - one G. It should kill you all out of sheer boredom.’

‘We know no better, Tessa.’

‘Yow know better. You've been on Settlements. There you can pick your gravitational pull to suit yourself. You can exercise at low gravity. You can lighten the strain on your tissues now and then. How can you live without that?’

‘We exercise here on Earth, too.’

‘Oh please - you do it with that pull, that eternal pull, yanking down on you. You spend all your time fighting it instead of letting your muscles interplay. You can't leap, you can't fly, you can't soar. You can't let yourself drop into the greater pull or rise into the lesser one. And that pull, pull, pull drags every bit of you down, so that you sag and wrinkle and age. Look at me! Look at me!’

‘I look at you as often as I can,’ said Fisher solemnly.

‘Don't look at me, then. If you do, you'll throw me over. And if you do that , I'll go back to Adelia.’

‘No, you won't. What will you do there after you've exercised at low gravity? Your research work, your laboratories, your team are all here.’

‘I'll start over and build a new team.’

‘And will Adelia support you in the style to which you are now accustomed? Of course not. You'll have to admit that Earth is not stinting you, that you are getting all you want. Wasn't I right?’

‘Weren't you right? Traitor! You didn't tell me that Earth had hyper-assistance. You also didn't tell me that they had discovered the Neighbor Star. In fact, you let me pontificate on the uselessness of Rotor's Far Probe and never once told me that it had discovered anything more than a few parallaxes. You sat there and laughed at me, like the heartless wretch you are.’

‘I would have told you, Tessa, but what if you had decided not to come to Earth? It was not my secret to give you.’

‘But after I came to Earth?’

‘As soon as you got to work, actually to work, we told you.’

‘They told me, and left me feeling stunned and foolish. You might have given me just a hint so that I wouldn't come off like such an idiot. I should have killed you, but what could I do? You're addictive. You knew you were when you heartlessly seduced me into coming to Earth.’

That was a game she insisted on playing, and Fisher knew his role. He said, ‘Seduced you? You insisted. You wouldn't have it any other way.’

‘You liar. You forced yourself on me. It was rape - impure and complex. And you're going to do it again. I can see it in those dreadful lust-filled eyes.’

It had been months since she had played that particular game and Fisher knew it came when she was satisfied with herself professionally. He said afterward, ‘Have you made progress?’

‘Progress? I think you can call it that.’ She was panting. ‘I have a demonstration that I've set up for tomorrow for your decaying and ancient Earthman, Tanayama. He's been pushing for it mercilessly.’

‘He's a merciless fellow.’

‘He's a stupid fellow. You'd think that even if a society doesn't know science, they would know something about science, about how it works. If they give you a million global credits in the morning, they shouldn't expect anything definite by evening the same day. They should at least wait till the next morning and give you the whole night to work in. Do you know what he said to me last time we spoke, when I said I might have something to show him?’

‘No, you hadn't told me. What did he say?’

‘You'd think he'd say: “It's amazing that in a mere three years you've worked out something so astonishing and new. We must give you enormous credit and the weight of gratitude we feel toward you is immeasurable.” That's what you would think he would say.’

‘No, not in a million years would I think that Tanayama would say anything like that. What did he say?’

‘He said, “So you have something finally, after three years. I should hope so. How long do you think I have to live? Do you think I have been supporting you, and paying for you and feeding you an army of assistants and workers in order to have you produce something after I'm dead and can't see it?” That's what he did say, and I tell you I would like to delay the demonstration till he is dead, for my own satisfaction, but I suppose that the work comes first.’

‘Do you really have something that will satisfy him?’

‘Only superluminal flight. True superluminal flight, not that hyper-assistance nonsense. We now have something that will open the door to the Universe.’

The site where Tessa Wendel's research team labored, intent on shaking the Universe, had been prepared for her even before she had been recruited and come to Earth. It was inside a vast mountainous redoubt that was totally off-limits to Earth's teeming population, and in it a veritable city of research had been built.

And now Tanayama was there, seated in a motorized chair. Only his eyes, behind their narrowed lids, seemed alive - sharp, glancing this way and that.

He was by no means the highest figure in Earth's government, not even the highest figure then present, but he had been, and still was, the force behind the project and all automatically gave way to him.

Only Wendel seemed unintimidated.

His voice was a rustling whisper. ‘What will I see, Doctor? A ship?’

There was no ship in view, of course.

Wendel said, ‘No ship, Director. Ships are years away. I have only a demonstration, but it is an exciting one. You will see the first public demonstration of true superluminal flight, something that is far beyond hyper-assistance.’

‘How am I going to see that?’

‘It was my understanding, Director, that you have been briefed.’

Tanayama coughed wrackingly and had to pause to catch his breath. ‘They tried to talk to me,’ he said, ‘but I want it from you.’ His eyes, baleful and hard, were fixed on her. ‘You're in charge,’ he said. ‘It is your scheme. Explain.’

‘I can't explain the theory. That would take too long, Director. It would tire you.’

‘I want no theory. What am I going to see ?’

‘What you are going to see are two cubical glass containers. Both contain a hard vacuum.’

‘Why a vacuum?’

‘Superluminal flight can only be initiated in a vacuum, Director. Otherwise the object made to move faster than light drags matter with it, increasing energy expenditures and decreasing controllability. It must end in a vacuum, too, or else the result can be catastrophic because-’

‘Never mind the “because”. If this superluminal flight of yours must begin and end in a vacuum, how do we make use of it?’

‘It is necessary, first, to move out into outer space by ordinary flight and then move into hyperspace and stay there. You arrive near your destination and move out into ordinary space, and then make the final move by ordinary flight.’

‘That takes time.’

‘Even superluminal flight can't be done instantaneously, but if you can move from the Solar System to a star forty light-years away in forty days rather than forty years, it would be ungrateful to grumble over the time lapse.’

‘All right, then. You have these two cubical glass containers. What of them?’

‘They are holographic projections. Actually, they are three thousand kilometers apart through the body of the Earth, each in a mountain fastness. If light could travel from one to the other through unobstructed vacuum, it would take that light fully 1/1000th of a second - one millisecond - to make the passage. We're not going to use light, of course. Suspended in the middle of the cube at the left, held in space by a powerful magnetic field, is a small sphere, which is actually a tiny hyperatomic motor. Do you see it, Director?’

‘I see something there,’ said Tanayama. ‘Is that all you have?’

‘If you will watch carefully, you will see that it will disappear. The countdown is progressing.’

It was a whisper in each person's ear, and, at zero, the sphere was gone from one cube and present in the other.

‘Remember,’ said Wendel, ‘those cubes are really three thousand kilometers apart. The timing mechanism shows that the duration between the departure and the arrival was a little over ten microseconds, which means that the passage took place at almost a hundred times the speed of light.’

Tanayama looked up. ‘How can I tell? The whole thing could be a trick designed to fool someone you believe to be a gullible old man.’

‘Director,’ said Wendel sternly. ‘There are hundreds of scientists here, all with reputations, a number of them Earthmen. They will show you anything you want to see, explain how the instruments work. You will find nothing here but honest science done well.’

‘Even if all is as you say, what does it mean? A little ball. A Ping-Pong ball, traveling a few thousand kilometers. Is that what you have after three years?’

‘What you have seen is perhaps more than anyone had a right to expect, Director, with all due respect. What you have seen may be the size of a Ping-Pong ball, and it may have traveled no more than three thousand kilometers, but it is true superluminal flight just as much as if we had moved a starship from here to Arcturus at a hundred times the speed of light. What you have seen is the first public demonstration of true superluminal flight in human history.’