Imperial Earth

Sirius would ultimately reach the nearest stars, in not much more than a thousand years…. All these things they could do; however, human nature having certain invariants, a majority of Sirius’ passengers had other possibilities in mind.

It was the only chance most of them would ever have of experiencing weightlessness long enough to enjoy it. What a crime to waste the opportunity! No wonder that the most popular item in the ship’s library these last few days had been the Nasa Sutra, an old book and an old joke, explained so often that it was no longer funny.

Captain Ivanov denied, with a reasonably convincing show of indignation, that the ship’s schedule had been designed to pander to the passenger’s lower instincts. When the subject had been raised at the Captain’s table, the day before Turnaround, he had put up quite a plausible defense.

“It’s the only logical time to shut down the Drive,” he had explained.

“Between zero zero and zero four, all the passengers will be in their cabins, er, sleeping. So there will be the minimum of disturbance. We couldn’t close down during the day-remember, the kitchens and the toilets will be out of action while we’re weightless. Don’t forget that! We’ll remind everyone in the late evening, but some idiot always gets overconfident, or drinks too much, and doesn’t have enough sense to read the instructions on those little plastic bags you’ll find in your cabins-no thanks, Steward, I don’t feel like soup.”

Duncan had been tempted; Marissa was beginning to fade, and there was no lack of opportunity. He had received unmistakable signals from several directions, and for groups with all values of n from one to five. It would not have been easy to make a choice, but Fate had saved him the trouble.

It was a full week, and Turnaround was only three days ahead, before he had felt confident enough of his increasing intimacy with Chief Engineer

Mackenzie to drop some gentle hints. They had not been rejected out of hand, but Warren obviously wanted time to weigh the possibilities. He gave

Duncan his decision only twelve hours in advance.

“I won’t pretend this might cost me nay job,” he said, “but it could be embarrassing, to say the least, if it got around. But you are a Makenzie, and a Special Assistant to the Administrator, and all that. If the worst comes to the worst, which I hope it won’t, we can say your request’s official.”

“Of course. I understand completely, and I really appreciate what you’re doing. I won’t let you down.” . “Now there’s the question of timing. If everything checks out smoothly-and I’ve no reason to expect otherwise-I’ll be through in two hours and can dismiss my assistants. They’ll leave like meteors-they’ll all have something lined up, you can be sure of that -so we’ll have the place to ourselves. I’ll give you a call at zero two, or as soon after as possible.”

“I hope I’m not interrupting any~ ah-personal plans you’ve made.”

“As it happens, no. The novelty’s worn off. What are you smiling at?”

“It’s just occurred to me,” Duncan answered, “that if anyone does meet the pair of us at two o’clock on the morning of Turnaround, we’ll have a perfect alibi …. “

Nevertheless, he felt a mild sense of guilt as he drifted along the corridors behind Warren Mackenzie. The weightless-but far from sleeping-ship might have been deserted, for there was no occasion now for anyone to descend below the freight deck on Level Three. It was not even necessary to pretend that they were heading for an innocent assignation.

Yet the guilt was there, and he knew why. He was taking advantage of a friendship for secret purposes of his own, by suggesting that his interest in the Asymptotic Drive was no more than would be expected from anyone with a scientific or engineering background. But perhaps Warren was not as naieve as he seemed; he could hardly be unaware that the Drive posed a threat to the entire economy of Duncan’s society. He might even be trying to help, in a tactful way.

“You may be disappointed,” said Warren as they passed through the bulkhead floor separating levels Three and Two. “There’s not much to see. But what there is is enough to give some people nightmares which is why we discourage visitors.”

Not the most important reason, thought Duncan. The Drive was not exactly a secret; there was an immense literature on the subject, from the most esoteric mathematical papers down to popularizations so elementary that they amounted to little more than: “You pull on your bootstraps, and away you go.” But it would be fair to say that Earth’s Space Transportation