Outside the almost invisible windows, Earth and stars marched in a silent procession. At the moment, this side of the Station was tilted away from the sun; otherwise, it would have been impossible to look out, for the lounge would have been blasted with light. Even as it was, the glare of the Earth, filling half the sky, drowned all but the brighter stars.

But Earth was waning, as the Station orbited toward the night side of the planet; in a few minutes it would be a huge black disk, spangled with the lights of cities. And then the sky would belong to the stars.

"Now," said Dimitri, after he had swiftly downed his first drink and was toying with the second, "what's all this about an epidemic in the U.S. Sector? I wanted to go there on this trip. 'No, Professor,' they told me. 'We're very sorry, but there's a strict quarantine until further notice.' I pulled all the strings I could; It was no use. Now you tell me what's happening."

Floyd groaned inwardly. Here we go again, he said. The sooner I'm on that shuttle, headed for the Moon, the happier I'll be.

"The – ah – quarantine is purely a safety precaution," he said cautiously. 'We're not even sure it's really necessary, but we don't believe in taking chances."

"But what is the disease – what are the symptoms? Could it be extraterrestrial? Do you want any help from our medical services?"

"I'm sorry, Dimitri – we've been asked not to say anything at the moment. Thanks for the offer, but we can handle the situation."

"Hmm," said Moisevitch, obviously quite unconvinced. "Seems odd to me that you, an astronomer, should be sent up to the Moon to look into an epidemic."

"I'm only an ex-astronomer; it's years since I did any real research. Now I'm a scientific expert; that means I know nothing about absolutely everything."

"Then do you know what TMA-1 means?"

Miller seemed about to choke on his drink, but Floyd was made of sterner stuff. He looked his old friend straight in the eye, and said calmly: "TMA-1? What an odd expression. Where did you hear it?"

"Never mind," retorted the Russian. "You can't fool me. But if you've run into something you can't handle, I hope you don't leave it until too late before you yell for help."

Miller looked meaningfully at his watch.

"Due to board in five minutes, Dr. Floyd," he said. "I think we'd better get moving."

Though he knew that they still had a good twenty minutes, Floyd got up with haste. Too much haste, for he had forgotten the one-sixth of a gravity. He grabbed the table just in time to prevent a takeoff.

"It was fine meeting you, Dimitri," he said, not quite accurately. "Hope you have a good trip down to Earth – I'll give you a call as soon as I'm back."

As they left the lounge, and checked through the U.S. transit barrier, Floyd remarked: "Phew – that was close. Thanks for rescuing me."

"You know, Doctor," said the Security Officer, "I hope he isn't right."

"Right about what?"

"About us running into something we can't handle."

"That," Floyd answered with determination, "is what I intend to find out."

Forty-five minutes later, the Aries-lB lunar carrier pulled away from the Station. There was none of the power and fury of a takeoff from Earth – only an almost inaudible, far-off whistling as the low-thrust plasma jets blasted their electrified streams into space. The gentle push lasted for more than fifteen minutes, and the mild acceleration would not have prevented anyone from moving around the cabin. But when it was over, the ship was no longer bound to Earth, as it had been while it still accompanied the Station. It had broken the bonds of gravity and was now a free and independent planet, circling the sun in an orbit of its own.

The cabin Floyd now had all to himself had been designed for thirty passengers. It was strange, and rather lonely, to see all the empty seats around him, and to have the undivided attention of the steward and stewardess – not to mention pilot, copilot, and two engineers. He doubted that any man in history had ever received such exclusive service, and it was most unlikely that anyone would do so in the future. He recalled the cynical remark of one of the less reputable pontiffs: "Now that we have the papacy, let us enjoy it." Well, he would enjoy this tip, and the euphoria of weightlessness. With the loss of gravity he had – at least for a while – shed most of his cares. Someone had once said that you could be terrified in space, but you could not be worried there. It was perfectly true.

The stewards, it appeared, were determined to make him eat for the whole twenty-five hours of the trip, and he was continually fending off unwanted meals. Eating in zero gravity was no real problem, contrary to the dark forebodings of the early astronauts. He sat at an ordinary table, to which the plates were clipped, as aboard ship in a rough sea. All the courses had some element of stickiness, so that they would not take off and go wandering round the cabin. Thus a chop would be glued to the plate by a thick sauce, and a salad kept under control by an adhesive dressing. With a little skill and care there were few items that could not be tackled safely; the only things banned were hot soups and excessively crumbly pastries. Drinks of course, were a different matter; all liquids simply had to be kept in plastic squeeze tubes.

A whole generation of research by heroic but unsung volunteers had gone into the design of the washroom, and it was now considered to be more or less foolproof. Floyd investigated it soon after free fall had begun. He found himself in a little cubicle with all the fittings of an ordinary airline toilet, but illuminated with a red light that was very harsh and unpleasant to the eye. A notice printed in prominent letters announced: MOST IMPORTANT! FOR YOUR OWN COMFORT, PLEASE READ THESE INSTRUCTIONS CAREFULLY!

Floyd sat down (one still tended to do so, even when weightless) and read the notice several times. When he was sure that there had been no modifications since his last trip, he pressed the START button.

Close at hand, an electric motor began to whirr, and Floyd felt himself moving. As the notice advised him to do, he closed his eyes and waited. After a minute, a bell chimed softly and he looked around.

The light had now changed to a soothing pinkish-white; but, more important, he was under gravity again.

Only the faintest vibration revealed that it was a spurious gravity, caused by the carrousel-like spin of the whole toilet compartment. Floyd picked up a piece of soap, and watched it drop in slow motion; he judged that the centrifugal force was about a quarter of a normal gravity. But that was quite enough; it would ensure that everything moved in the right direction, in the one place where this mattered most.

He pressed the STOP FOR EXIT button, and closed his eyes again. Weight slowly ebbed as the rotation ceased, the bell gave a double chime, and the red warning light was back. The door was then locked in the right position to let him glide out into the cabin, where he adhered as quickly as possible to the carpet. He had long ago exhausted the novelty of weightlessness, and was grateful for the Velcro slippers that allowed him to walk almost normally.

There was plenty to occupy his time, even if he did nothing but sit and read. When he tired of official reports and memoranda and minutes, he would plug his foolscap-sized Newspad into the ship's information circuit and scan the latest reports from Earth. One by one he would conjure up the world's major electronic papers; he knew the codes of the more important ones by heart, and had no need to consult the list on the back of his pad. Switching to the display unit's short-term memory, he would hold the front page while he quickly searched the headlines and noted the items that interested him.