A few minutes past four, the loading-bay hatch slowly opened downward, like the jaw of a shark. It came to a stop, making a platform more than four feet off the ground.

The men who were assembled near the ship stood on both sides of the hatch, looking up. First appeared two tractor tracks, wide apart, sliding forward with a roar, as though the huge machine were going to dive wildly into the air. They could see its grayish-yellow underside. Then it rocked and lurched forward, hitting the platform flat, and so hard that there was a great clang. Moving on its tracks, it drove-fell across the gap to the ground, catching the ground at a sharp angle and biting into it. In the next second, Defender’s flattened head was level, and after about forty feet it came to a halt with a pleasant rumble.

“Well, now, friends” — the Engineer stuck his head out the small rear door — “go in the ship, because it’s going to get hot, and stay there for at least half an hour. Better yet, send Blackie out first and let him check for radioactivity.”

The door closed. The three men entered the tunnel, taking the robot with them. Shortly afterward a metal piece appeared in the tunnel mouth, filling the opening entirely. Inside Defender, the Engineer wiped the screens, checked the dials, and said, “Let’s get started.”

Defender’s nose — short and slender, and encircled by little cylinders — turned westward.

The Engineer, centering the hedge in his cross hairs, glanced to the side at the dials and stepped on the pedal.

For a second the screen went dark, and Defender was rocked by a blast of air and a noise as if a giant had pressed his mouth to the ground and said, “Oof!” The screen cleared.

A fiery cloud rose, and the air blurred around it like a liquid. A thirty-foot section of hedge had disappeared, and steam billowed from a depression with an incandescent red rim. Farther on, molten glass glittered in the sun.

“Too much power,” thought the Engineer, but all he said was, “All right, let’s go.” The hulk moved toward the crater with a strange lightness; the crew hardly shook at all as they rode through it. At the bottom, some of the glowing glass had begun to solidify. “We’re barbarians,” the Doctor thought. “What am I doing here?”

The Engineer made a slight correction for direction and accelerated. Defender rode as though on a highway, the tracks turning smoothly and softly. They were doing almost forty miles an hour without even noticing it.

“Can we open the top?” asked the Doctor, who was sitting in a low seat. Over his shoulder there was a small convex screen, like a porthole.

“Of course,” the Engineer said and pushed a button.

From the rim of the turret a fluid squirted in needle-sharp streams, washing the bits of radioactive ash off the armor plates. Then everything became bright — the head opened, the top slid back, and the sides collapsed into the body — and they rode on, now protected only by a thick windshield that curved around them. The air ruffled their hair.

“I’m afraid the Captain was right,” the Chemist muttered some time later. The landscape was unchanging. They sailed over a sea of sand, the heavy vehicle swaying gently as it crossed fin-shaped dunes in the same uninterrupted rhythm. The Engineer increased speed, the ride became much rougher, and the tracks threw up clouds of sand, some of which got inside.

At thirty miles the excessive rocking stopped. They traveled in this fashion for more than two hours.

“Yes, I guess he was,” said the Engineer, changing course from west to southwest.

The next hour brought no change, and they turned again, heading in a more southerly direction.

By now they had gone ninety miles.

The sand changed. From white and very fine, trailing behind them like a long sweeping tail, it became reddish, coarser, and didn’t rise in clouds when the tracks churned it up. The dunes became fewer and lower. From time to time they passed the protruding stalks of buried bushes. Blurry patches appeared in the distance, slightly off course. The Engineer steered toward them. They grew quickly in size, and a few minutes later the men saw vertical slabs rising from the sand, resembling fragments of walls.

Entering a narrow passage, on either side of which stood slanting quoins eaten by erosion, they slowed down. A huge stone blocked their way. Defender raised its head and rode over that obstacle easily; they found themselves in a long alley. Through the gaps between the slabs they could see other ruins, all worn and pitted. Then they drove out into an open space, dunes appeared again, but small, packed, producing no dust, and the terrain began to slope downward. In the distance, below, they could see truncated club-shaped rocks and more ruins.

The bottom was littered with speckled stones. They crossed it and went up another slope. The ground grew harder; the tracks no longer sank into it. The first clumps of scrub appeared. They were almost black, but appeared deep red in the low sun, as though their podlike leaves were filled with blood.

Farther on, the scrub rose higher, blocking their way in places. Defender pushed through it, not slowing down. This produced an unpleasant hollow crackling, the sound of thousands of small blisters bursting, squirting a dark sticky substance that stained the cer-amite plates. Soon the whole vehicle, up to the turret, was reddish brown.

They had gone 120 miles. The sun now touched the western horizon, and the shadow of the vehicle lengthened more and more. Suddenly there was a terrible grating under them, a crunching. The Engineer braked, but it took Defender about forty feet to come to a stop. In the wide trail that they had beaten down behind them lay, among the mangled bushes, pieces of a rusted metal frame. They rode on — and again hit metal, twisted grillwork, sheets riddled with holes, curved ribs. Smashed beneath Defender’s tracks, this scrap was covered with the substance that oozed from the broken plants.

The wall of scrub grew still higher before them, but the awful grating and squealing of rusted metal stopped. Unexpectedly, the black stalks that had been battering them parted, and the crew entered a glade fifty to sixty feet wide and hemmed in, at the other end, by the same dark thicket. The Engineer turned, and they went down a long sloping clearing that resembled a forest path. The surface was clayey, covered with loamy patches, which indicated that water occasionally flowed there.

The clearing did not run straight. Sometimes the red sun, half sunk in the horizon and enormous, appeared in front of the machine, dazzling them. Sometimes the sun was hidden and sent blood-red flashes through the dense thicket that now was nine feet high. Then they saw the whole sunset, and a vast multicolored expanse before it. The land was about two thousand feet below them.

A sheet of water sparkled in the distance, reflecting the sun. On the shore of this lake, which was uneven and covered with patches of dark scrub, stood buildings, machines on splayed legs, and nearer the cliff where Defender had halted was a mosaic of structures, rows of vertical masts, bright avenues.

There was considerable animation below: gray, brown, and white dots crept along the avenues, intermingling, forming clusters, spreading out in long strings. This entire scene of habitation was filled with tiny flashes, as though the people were continually opening and closing the windows of their houses and the sunlight played in the panes.

The Doctor gave a cry of delight. “Henry, you’ve done it! At last, something normal. Everyday life, and what a great observation post!” And he began to climb out of the open turret.

The Engineer stopped him. “Hold on. Don’t you see the sun? In five minutes it’ll be down, and we won’t be able to see a thing. We ought to put this entire panorama on film, and quickly, too.”

The Chemist had already pulled the cameras out from under the seat, and together they set up the largest, which looked like a blunderbuss. The tripod they threw to the ground. The Engineer took a coil of nylon line, tied one end of it to the turret, tossed the rest of it over Defender’s front end, and jumped down. The other two had already raised the tripod and were running to the cliff edge. He caught up with them and fastened the line to a snap-hook on each man’s belt.

“In case you fall,” he said.

The sun was sinking into the fiery waters of the lake. There was a hasty murmur of machinery, and the enormous lens tilted downward. The Doctor knelt to support the front legs of the tripod, and the Chemist put his eye to the finder and grimaced.

“Too much glare,” he said. “I need the diaphragm!”

The Engineer ran back and returned a moment later with the attachment, and the shooting began.

Holding the bar with both hands, the Engineer slowly moved the camera from left to right. Now and then the Chemist stopped it, increasing the resolution on places where the finder showed a greater concentration of detail. The Doctor went on kneeling as the camera purred. The film flew, and the spools were changed almost without a pause. Barely a sliver of the solar disk remained above the water as the lens pointed at the movement directly below. The Doctor had to lean over the edge now with the camera, hanging on to the taut line, and beneath him he saw the folds of the clay wall bathed in a crimson that grew dimmer and dimmer. Near the end of the second spool, the red disk disappeared. The sky still glowed, but a gray-blue shadow fell over the plain and the lake, and apart from the flashes there was nothing more to be seen.

The three men carried the camera back carefully, as though it were a treasure.

“Do you think the pictures will turn out?” the Chemist asked the Engineer.

“We’ll find out in the ship. We can always come back.”

They put the camera and the spools in Defender and returned to the cliff. Only now did they notice that on the eastern shore of the lake was a steep wall that merged into the landscape. Its summit caught the final pink gleam of the sunset, and above it, far in the distance, a russet column of smoke poured into the sky with the first stars. “Ah, that must be the valley, the geyser,” the Chemist exclaimed to the Doctor.

They looked down again. White and green sparks slowly spread in a line along the edge of the lake, the line sometimes forking, like a river. As it grew darker, the number of lights increased. The tall thicket, now completely black, rustled peacefully overhead. They turned away reluctantly, so beautiful was the view, and took with them the image of the lake reflecting milky stars.

As they walked back, the Doctor asked the Chemist, “What did you see?”

The Chemist smiled, embarrassed. “Nothing. I wasn’t really looking, I was concentrating on making the adjustments, on the focusing, and Henry moved so quickly…”

“It doesn’t matter,” said the Engineer, leaning against Defender’s cold hull. “We took two hundred frames a second, and we’ll see everything when the film is developed.”

“An idyllic excursion,” said the Doctor.

The Engineer switched the rear telescreen and put Defender into reverse. They went uphill for a while, but when they came to a wider place, they turned and headed due north.

“We’re not taking the same route back,” said the Engineer. “That would add something like sixty miles. I’ll follow the clearing as long as I can. We should be there within two hours.”