He said, ‘Then you think that interstellar flight is impossible?’

‘In a practical sense, yes, if hyper-assistance is all there is.’

Fisher said, ‘You make it sound as though hyper-assistance isn't all there is, Tessa.’

‘It may be all there is. It wasn't long ago when we thought that even that much was impossible and to go further yet-Still, we can at least dream of true hyperspatial flight and true superluminal velocities. If we could go as quickly as we wished for as long as we wished, then the Galaxy, perhaps the Universe, would become one large Solar System, so to speak, and we could have it all.’

‘That's a nice dream, but is it possible?’

‘We've had three All-Settlement Conferences on the matter since Rotor's flight.’

‘Just All-Settlement? What about Earth?’

‘There were Earth observers present, but Earth is not a physicists' paradise these days.’

‘What conclusions did the conference reach?’

Wendel smiled. ‘You're not a physicist.’

‘Leave out the hard parts. I'm curious.’

She merely smiled at him.

Fisher clenched his fist on the table before him. ‘Forget this theory of yours that I'm some sort of secret agent after your information. I have a child out there somewhere, Tessa. You say she's probably dead. What if she's alive? Is there a chance-’

Wendel's smile disappeared. ‘I'm sorry. I did not think of that. But be practical. Finding a Settlement somewhere in a volume of space that is represented by a sphere that, at the present time, is six light-years in radius and is growing ever larger with time is an impossible task. It took us over a century to find the tenth planet, and that was enormously larger than Rotor and a much smaller volume of space had to be combed.’

Fisher said, ‘Hope springs eternal. Is true hyperspatial flight possible? You can say yes or no.’

‘Most say no - if you want the truth. There may be a few who say they can't say, but they tend to mumble.’

‘Does anyone say yes right out loud?’

‘One person that I know of does. I do.’

‘You think it's possible ?’ said Fisher with an astonishment he did not have to fake. ‘Do you say that openly, or is it something you tell yourself in the dark of the night?’

‘I've published on the subject. One of those articles you only read the title of. No-one dares agree with me, of course, and I've been wrong before, but I think I'm right now.’

‘Why do the others all think you're wrong?’

‘That's the hard part. It's a matter of interpretation. Hyper-assistance on the Rotorian model, the techniques of which are by now understood in the Settlements generally, by the way, depends on the fact that the product of the ratio of ship speed to light speed, multiplied by time, is a constant, where the ratio of ship speed to light speed is greater than one.’

‘What does that mean?’

‘That means that when you go faster than light, the faster you go, the shorter the time you can maintain the speed, and the longer the time you must go more slowly than light before you can get a boost over it again. The result is that, in the end, your average speed over a particular distance is no greater than the speed of light.’

‘Well?’

‘That makes it sound as though the uncertainty principle is involved, and the uncertainty principle, all of us are convinced, can't be fooled with. If the uncertainty principle is involved, then true hyperspatial flight would seem to be theoretically impossible, and most physicists have come down on that side of the argument, while the rest of them waffle. My view, however, is that what's involved merely seems like the uncertainty principle but isn't, and that true hyperspatial flight is, therefore, not eliminated.’

‘Can the matter be settled?’

‘Probably not,’ said Wendel, shaking her head. ‘The Settlements are definitely not interested in wandering off with mere hyper-assistance. No-one is going to repeat the Rotorian experiment and voyage for years to probable death. On the other hand, neither is any Settlement going to invest an incredible amount of money, resources and effort in order to try to work out a technique that the vast majority of experts in the field are convinced is theoretically impossible.’

Fisher leaned forward, ‘Doesn't that bother you?’

‘Of course it bothers me. I'm a physicist and I'd like to prove that my view of the Universe is the correct one. However, I've got to accept the limits of the possible. It will take enormous sums and the Settlements will give me nothing.’

‘But, Tessa, even if the Settlements are not interested, Earth is - and to any amount.’

‘Really?’ Tessa smiled in what seemed mild amusement and she reached out to stroke Fisher's hair, slowly and sensually. ‘I thought we'd get to Earth eventually.’

Fisher seized Wendel's wrist and gently drew her hand away from his head. He said, ‘You've been telling me the truth about your opinions of hyperspatial flight, haven't you?’

‘Completely.’

He said, ‘Then Earth wants you.’

‘Why?’

‘Because Earth wants hyperspatial flight, and you're the one important physicist who thinks it can be done.’

‘If you knew that, Crile, why the cross-examination?’

‘I didn't know it until you told me so. The only information I had been given was that you were the most brilliant physicist alive today.’

‘Oh, I am, I am,’ said Wendel mockingly. ‘And you were sent to get me?’

‘I was sent to persuade you.’

‘Persuade me to do what? To come to Earth? Overcrowded, filthy, impoverished, wracked by uncontrolled weather. What an enticing thought.’

‘Listen to me, Tessa. Earth is not all of a piece. It may have all those faults, but there are parts that are beautiful and peaceful and that is all you would see. You don't really know what Earth is like. You've never been there, have you?’

‘Never. I'm Adelian, born and bred. I have been to other Settlements, but I've never been to Earth, thank you.’

‘Then you can't know what Earth is like. You can't know what a large world is. A real world. You live here enclosed, in a toy box, with a few square kilometers of surface, with a handful of people. You're living in a miniature that you've used up long ago and that has nothing more to offer you. Earth, on the other hand, is over six hundred million square kilometers of surface. It is eight billion human beings. It is infinite variety - lots of it very bad, but lots of it very good.’

‘And all of it very poor. And you have no science.’

‘Because scientists - and with them science - have moved out to the Settlements. That's why we need you and others. Come back to Earth.’

‘I still don't see why.’

‘Because we have goals, ambitions, desires. The Settlements have only self-satisfaction.’

‘What good are all those goals and ambitions and desires? Physics is an expensive pursuit.’

‘And Earth's per capita wealth is low, I admit it. Individually, we are poor, but eight billion people, each contributing something out of poverty, can amass a vast sum. Our resources, misused as they are and have been, are still enormous, and we can find more money and more labor than all the Settlements together - if it is for something we feel an absolute need. I assure you that Earth feels an absolute need for hyperspatial flight. Come to Earth, Tessa, and you will be treated as that rarest of resources, a brilliant brain we must have - and the one thing we can't supply on our own.’

Wendel said, ‘I'm not at all sure that Adelia would be willing to let me go. It may be a self-satisfied Settlement, but it knows the value of brains, too.’

‘They can't object to your attending a scientific meeting on Earth.’

‘And once there, you mean, I needn't return?’

‘You will have no complaint with regard to treatment. You will be more comfortable there than you are here. Your every desire, your every wish- More than that, you can head the hyperspatial project and you will have an unlimited budget to devise tests of any kind, run experiments, make observations-’

‘Well! What a princely bribe you offer me!’

Fisher said earnestly, ‘Is there anything more you can ask for?’

‘I wonder,’ said Wendel. ‘Why were you sent? An attractive man like you? Were they expecting you to bring back an elderly female physicist - susceptible - frustrated - drawn by your body like a fish by a hook?’

‘I don't know what was in the mind of those who sent me, Tessa, but that was not in my mind. Not after one look at you. You are not elderly, as you well know. I don't for a minute believe that you are either susceptible or frustrated. Earth is offering you a physicist's dream. That has nothing to do with whether you are male or female, elderly or youthful.’

‘What a shame! Suppose I proved recalcitrant and didn't wish to go to Earth? What were you to do as a last measure of persuasion? Suppress your distaste for the process and make love to me?’

Wendel crossed her arms over her magnificent breasts and looked at him quizzically.

Fisher said carefully, choosing his words, ‘Again, I cannot say what was in the mind of those who sent me. Making love was not part of my explicit instructions, nor was it part of my intentions, though if it had been, I assure you that I would feel no distaste at the prospect. I felt, however, that you would see the advantages from a physicist's point of view and I would not denigrate you by supposing that you would need anything more.’

‘How wrong you are,’ said Wendel. ‘I see the advantages from a physicist's point of view, and I am anxious to accept the offer and to pursue the butterfly of hyperspatial flight down the corridors of the possible - but I do not wish to give up your best efforts at persuasion either. I want it all.’

‘But-’

‘In short, if you want me, you must pay me. Persuade me as though I were recalcitrant, as best as ever you can, or I won't go to Earth. Come, why do you suppose we are here in a Privacy? What do you think Privacies are for? Once we have exercised, showered, eaten a bit, drank a little, conversed, experienced some pleasure in all these things, there is opportunity to experience others. I insist. Persuade me to come to Earth.’

And at the touch of her finger, the light within the Privacy dimmed seductively.