Imperial Earth

There was no perceptible sense of motion, but the great ringed globe began to creep slowly down the observation window. The passengers in

front craned forward to follow it, and there was a chorus of disappointed “Ohs” as it finally sank from view below the wide skirting that surrounded the lower part of the ship. That band of metal had one purpose only-to block any radiation from the jet that might stray forward. Even a momentary glimpse of that intolerable glare, bright as a -supernova at the moment of detonation, could cause total blindness; a few seconds’ exposure would be lethal.

Sirius was now aimed almost directly at the sun, as she accelerated toward the inner planets. While the drive was on, there could be no rear-viewing.

Duncan knew that when he next saw Saturn with his unaided eyes, it would be merely a not-very-distinguished star.

A day later, moving at three hundred kilometers a second, the ship passed another milestone. She had, of course, escaped from the planet’s gravitational field hours earlier; neither Saturn-nor, for that matter, the

Sun-could ever recapture her. The frontier that Sirius was crossing now was a purely arbitrary one: the orbit of the outermost moon.

Mnemosyne, only fifteen kilometers in diameter, could claim two modest records. It had the longest period of any satellite, taking no fewer than 1,139 days to orbit Saturn, at an average distance of twenty-one million kilometers. And it also had the longest day of any body in the Solar

System, its period of rotation being an amazing 1,143 days. Although it seemed obvious that these two facts must be connected, no one had been able to arrive at any plausible explanation of Mnemosyne’s sluggish behavior.

Purely by chance, Sirius passed within fewer than a million kilometers of the tiny world. At first, even under the highest power of the ship’s telescope, Mnemosyne was only a minute crescent showing no visible features at all, but as it swiftly grew to a half-moon, patches of light and shade merged which eventually resolved themselves into craters. It was typical of all the denser, Mercury-type satellites-as

opposed to the inner snowballs like Mimas, Enceladus, and Tethys-but to Duncan it now held a special interest. It was more to him than the last landmark on the road to Earth.

Karl was there, and had been for many weeks, with the joint Titan-Terran

Outer Satellite Survey. Indeed, that survey had been in progress as long as

Duncan could remember-the surface area of all the moons added up to a surprising number of million square kilometers-and the TTOSS team was doing a thorough job. There had been complaints about the cost, and the critics had subsided only when promised that the survey would be so thorough that it would never be necessary to go back to the outer moons again. Somehow,

Duncan doubted that the promise would be kept.

He watched the pale crescent of Mnemosyne wax to full, simultaneously dwindling astern as the ship dropped sunward, and wondered fleetingly if he should send Karl a farewell greeting. But if he did, it would only be interpreted as a taunt.

It took Duncan several days to adjust to the complicated schedule of shipboard life-a schedule dominated by the fact that the dining room (as the lounge adjacent to the cafeteria was grandly called) could seat only one third of the passengers at a time. There were consequently three sittings for each of the three main meals-so for nine hours of every day, at least a hundred people were eating, while two hundred were either thinking about the next meal or grumbling about the last. This made it very difficult for the Purser, who doubled as Entertainment Officer, to organize any shipboard activities. The fact that most of the passengers had no wish to be organized did not help him.

Nevertheless, the day was loosely structured by a series of events, at which a good attendance was guaranteed by sheer boredom. There would be a thirty minute newscast from Earth at 0800, with a repeat at 1000, and updates in the evening at 1900 and 2100. At the beginning of the

voyage, the Earth news would be at least an hour and a half late, but it would become more and more timely as Sirius approached her destination.

When she reached her final parking orbit, a thousand kilometers above the

Equator, the delay would be effectively zero, and watches could at last be set by the radio time signals. Those passengers who did not realize this were liable to get into a hopeless state of confusion and, even worse, to miss meal sittings.