“Peron!” Elissa reached out and grabbed hold of his arm. “Keep a grip. We don’t want to be separated now.”

It was like being in a river and swept along by the current. With no effort on their part, they found themselves carried forward into a semicircular chamber and seated on soft benches covered with a warm velvety material. On either side people were grinning at them and staring out of the half-circle of the ports. “Look down!” said a woman next to Elissa. Her accent had peculiar vowel sounds to it, but it was easy to understand. “It’ll give you the shivers. No wonder it’s called Skydown.”

Elissa followed the other’s gesture, and found that the floor beneath their feet was transparent. She was looking directly down toward Earth, following the line of a giant silvery cylinder. As she watched, the doors of the chamber closed and they began a smooth, accelerated descent, their car riding an invisible path along the side of the cylinder.

“Peron.” Elissa leaned close to him so that he could hear her above the clamor. “What’s going on here? Look at them. They’re like the mob at the end of Planetfest. And where are we going?”

Peron shook his head. “It’s our own fault. I realized it as soon as we came out of the tanks there — we should have known we’re no different from anyone else. Don’t you see? Everybody from the planetary colonies and arcologies has been told about Earth since they were small children. They all want to visit. No wonder de Vries was amazed when you asked if he was coming with us — I bet people who live in the Sol system get tired of explaining things to the simpleminded visitors. Better face it, love, we’re just part of the tourist crowd.” Elissa looked around her at the restless, exuberant travellers. “You’re right — but they’re all having fun. You know what? I feel wonderful. I’m going to postpone solving the mysteries of the universe until we get back into orbit.” She grabbed Peron’s arm and pulled him closer. “Come on, misery. Let’s get into the spirit of it. Remember, a week down on Earth will only be five minutes in S-space — they won’t even notice that we’ve gone.”

They bent forward to look down through the floor. Although the cylinder was rushing past them as one continuous blur of motion, Earth was not perceptibly closer. It hung beneath them, a glittering white ball blocking out over fifteen degrees of the sky.

“I wonder how long the journey will be,” Elissa said. She reached out to the miniature information outlet built into the arm of her seat, and switched it on. “Speed, please, and arrival time.”

“Present speed, forty-four hundred kilometers an hour,” said a cheerful voice. The vocal reply system had been chosen with as pleasant and soothing a tone as possible. “Arrival will be three hours and forty-one minutes from now. We are still in the acceleration phase. We have thirty-three thousand four hundred kilometers to go to touchdown.”

“Where will we land?”

“Half a degree south of the equator, on one of the major continents.” Peron was still staring down at the globe beneath them. “This doesn’t look the way I expected — it’s too bright. Why so much cloud cover?”

There was a silence for a split second, as the on-board computer called back up to the synchronous station above them for assistance with the answer. “There is less cloud cover than usual today. You are probably mistaking snow cover for cloud cover.”

“But that would mean there’s snow over two-thirds of the surface!” “Correct.” Again the machine hesitated. “That is not unusual.”

“Earth was not snow-covered in the old days — is this a consequence of the old war?”

“Not at all. It is a result of reduced solar activity.” The information system hesitated for a moment, then went on: “The amount of received radiation from the Sun has declined by a small fraction of a percent over the past fifteen thousand years. The increased glaciation is apparent even from this distance. It is predicted that this Ice Age will persist for at least ten thousand more years, to be followed by an unusually warm period. Within fifteen thousand years there will be partial melting of the polar ice caps, and submergence of most coastal lands.”

Elissa reached out and switched off the set. She looked at Peron. “You don’t mind, do you? I had the feeling it was just getting into its stride. I hate being burbled at — whoever programmed that sequence needs brevity lessons from Kallen.”

Peron nodded his agreement. The view below was enough for their full attention. From the poles almost to the tropics, blue-white shining glaciers coated the land areas. The old outline of the larger land masses was unchanged. Soon Peron could see where the Skyhook was tethered. It met the surface on the west coast of the continent that had been known as Africa. They were descending rapidly toward that touchdown point, a couple of hundred kilometers from the place where the region’s mightiest river flowed to the Atlantic Ocean.

“We ought to decide what we really want to see,” said Elissa. “If we have a choice, I don’t care to travel around in the middle of a mob of sightseers.” “So let’s find out what the options are. Can you stand to have the information service on again for a couple of minutes?”

He touched the switch and spoke into the tiny microphone. “Will we be free to move as we choose when we reach the surface?”

“Of course.” The cheerful but impersonal voice answered at once. “There will be air and ground vehicles at your disposal, and personal information systems to go with you and answer any questions. Your account will automatically be charged for services.”

Elissa looked at Peron. To their knowledge, they had no credit account of any kind. They might have to fight that one with Jan de Vries when they returned from Earth.

“Do you have a site selected?” went on the service computer. “If so, we can schedule something to be available at once upon touchdown.”

“Wait a minute.” Peron turned away from the microphone. “Elissa? Let’s get away from everybody for a while. Maybe we’ll take a look at one typical Earth city, then let’s see some wild country.”

At her nod, Peron relayed their request to the machine. There was the longest silence so far.

“I am sorry,” said the voice at last. “We cannot grant your request.” “It is not permitted?” said Elissa.

“It would be permitted. But the environment you describe no longer exists.” Elissa said, “You mean there is no natural country left, anywhere on Earth?” “No,” said the voice. Peron imagined he could hear an element of surprise in the overall joviality of the machine’s tones. “There is natural country, plenty of it. But there are no towns or cities on Earth.”

The steady march of the glaciers had been more effective in the northern hemisphere. In Africa, Australia, and South America, the great oceans had moderated temperatures and checked the spread from polar regions. Occasional snow-free pockets could be found as far as forty degrees south of the equator. But in the north, the glaciers ruled everywhere past latitude thirty-five. Even at Skydown the temperature was chilly. Peron and Elissa emerged from the cable car at the foot of the Beanstalk to bright sunshine and clear skies, but they stood in a blustery east wind that encouraged warm clothing. While most of the visitors headed for a briefing on the sights of Earth, the two took an aircar and flew north.

They spent the first evening on the lush southern shore of the Mediterranean Sea near the ancient site of Tripoli. The information service computer informed them that they had reached the border for true forest land. Farther north, in what had once been Europe, only stunted stands of spruce and juniper persisted, clinging to south-facing slopes.

Night came quickly, sweeping in with a scented darkness across the white sandy beach. The aircar contained two bunks, but they were on opposite sides of the cabin. Peron and Elissa chose to sleep outside, protected by automatic sensors and the car’s warning system. Holding each other close beneath a moonless sky, they watched the wheel of unfamiliar constellations. Against that slow-moving backdrop, the space stations swept constantly overhead, one or more of them always visible. Sleep would not come easily. They whispered for a long time, of Pentecost, Planetfest, and Whirlygig, and of the accident to Peron that had plunged them across light-years and centuries.