"Got everything we need?" asked Tom.

"Everything we'll need—and about all we can safely carry without weighing ourselves down too much," answered Roger. "Enough food for a week, the rest of the Martian water, space goggles to protect our eyes from the sun and emergency lights for each of us."

"Not much to walk a hundred and fifty miles on," offered Astro. "Too bad the sand got in the galley and messed up the rest of that good food."

"We'll have plenty to get us by—if my calculations are right," said Tom. "One hundred and fifty-four miles to be exact."

"Exact only as far as my sun sight told me," said Roger.

"Do you think it's right?" asked Tom.

"I'll answer you this way," Roger replied. "I took that sight six times in a half hour and got a mean average on all of them that came out within a few miles of each other. If I'm wrong, I'm very wrong, but if I'm right, we're within three to five miles of the position I gave you."

"That's good enough for me," said Astro. "If we're going out there"—he pointed toward the desert—"instead of sitting around here waiting for Strong or someone to show up, then I'd just as soon go now!"

"Wait a minute, fellas. Let's get this straight," said Tom. "We're all agreed that the odds on Captain Strong's showing up here before our water runs out are too great to risk it, and that we'll try to reach the nearest canal. The most important thing in this place is water. If we stay and the water we have runs out, we're done for. If we go, we might not reach the canal—and the chance of being spotted in the desert is even smaller than if we wait here at the ship." He paused. "So we move on?" He looked at the others. Astro nodded and looked at Roger, who bobbed his head in agreement.

"O.K., then," said Tom, "it's settled. We'll move at night when it's cool, and try to rest during the day when it's the hottest."

Roger looked up at the blazing white sphere in the pale-blue sky that burned down relentlessly. "I figure we have about six hours before she drops for the day," he said.

"Then let's go back inside the ship and get some rest," he said.

Without another word, the three cadets climbed back inside the ship and made places for themselves amid the littered deck of the control room. A hot wind blew out of the New Sahara through the open port like a breath of fire. Stripped to their shorts, the three boys lay around the deck unable to sleep, each thinking quietly about the task ahead, each remembering stories of the early pioneers who first reached Mars. In the mad rush for the uranium-yielding pitchblende, they had swarmed over the deserts toward the dwarf mountains by the thousands. Greedy, thinking only of the fortunes that could be torn from the rugged little mountains, they had come unprepared for the heat of the Martian deserts and nine out of ten had never returned.

Each boy thought, too, of the dangers they had just faced. This new danger was different. This was something that couldn't be defeated with an idea or a sudden lucky break. This danger was ever present—a fight against nature, man against the elements on an alien planet. It was a battle of endurance that would wring the last drop of moisture mercilessly from the body, until it became a dry, brittle husk.

"Getting pretty close to sundown," said Tom finally. He stood beside the open port and shielded his eyes from the glare of the sun, now slowly sinking below the Martian horizon.

"I guess we'd better get going," said Roger. "All set, Astro?"

"Ready, Roger," answered the Venusian.

The three boys dressed and arranged the food packs on their backs. Tom carried the remainder of the Martian water, two quart plastic containers, and a six-yard square of space cloth, an extremely durable flyweight fabric that would serve as protection from the sun during the rest stop of the day. Roger and Astro carried the food in compact packs on their backs. Each boy wore a makeshift hat of space cloth, along with space goggles, a clear sheet of colored plastic that fitted snugly across the face. All three carried emergency lights salvaged from the wrecked ship.

Tom walked out away from the ship several hundred yards and studied his pocket compass. He held it steady for a moment, watching the needle swing around. He turned and walked slowly still watching the needle of the compass. He waited for it to steady again, then turned back to Roger and Astro who stood watching from the window port.

"This is the way." Tom pointed away from the ship. "Three degrees south of east, one hundred and fifty-four miles away, if everything is correct, should bring us smack on top of a major canal."

"So long, Lady Venus," said Astro, as he left the ship.

"Don't think it hasn't been fun," added Roger, "because it hasn't!"

Astro fell in behind Roger, who in turn followed Tom who walked some ten feet ahead. A light breeze sprang up and blew across the surface of the powdery sand. Ten minutes later, when they stopped to adjust their shoulder packs, they looked back. The breeze had obliterated their tracks and the mountain of sand covering the spaceship appeared to be no different from any of the other small dunes on the desert. The New Sahara desert of Mars had claimed another Earth-ship victim.

"If we can't see the Lady Venus standing still, and knowing where to look," said Astro, "how could a man in a rocket scout ever find it?"

"He wouldn't," said Roger flatly. "And when the water ran out, we'd just be sitting there."

"We're losing time," said Tom. "Let's move." He lengthened his stride through the soft sand that sucked at his high space boots and faced the already dimming horizon. The light breeze felt good on his face.

The three cadets had no fear of running into anything in their march through the darkness across the shifting sands. And only an occasional flash of the emergency light to check the compass was necessary to keep them moving in the right direction.

There wasn't much talk. There wasn't much to talk about. About nine o'clock the boys stopped and opened one of the containers of food and ate a quick meal of sandwiches. This was followed by a carefully measured ounce of water, and fifteen minutes later they resumed their march across the New Sahara.

About ten o'clock, Deimos, one of the small twin moons of Mars, swung up overhead, washing the desert with a pale cold light. By morning, when the cherry-red sun broke the line of the horizon, Tom estimated that they had walked about twenty miles.

"Think we ought to camp here?" asked Astro.

"If you can show me a better spot," said Roger with a laugh, "I'll be happy to use it!" He swung his arm in a wide circle, indicating a wasteland of sand that spread as far as the eyes could see.

"I could go for another hour or so," said Astro, "before it gets too hot."

"And wait for the heat to reach the top of the thermometer? Uh-huh, not me," said Roger. "I'll take as much sleep as I can get now—while it's still a little cool."

"Roger's right," said Tom. "We'd better take it easy now. We won't be able to get much sleep after noon."

"What do we do from noon until evening?" asked Astro.

"Aside from just sitting under this hunk of space cloth, I guess we'll come as close to being roasted alive as a human can get."

"You want to eat now?" asked Astro.

Tom and Roger laughed. "I'm not hungry, but you go ahead," said Tom. "I know that appetite of yours won't wait."

"I'm not too hungry either," said Roger. "Go ahead, you clobber-headed juice jockey."

Astro grinned sheepishly, and opening one of the containers of food, quickly wolfed down a breakfast of smoked Venusian fatfish.

Tom and Roger began spreading the space cloth on the sand that was already hot to the touch. Anchoring the four corners in the sand with the emergency lights and one of Tom's boots, they propped up the center with the food packs, one on top of the other. A crude tent was the result and both boys crawled in under, sprawling on the sand. Astro finished eating, lay down beside his two unit-mates, and in a moment the three cadets were sound asleep.

The sun climbed steadily over the desert while the Polaris unit slept. With each hour, the heat of the desert rose, climbing past the hundred mark, reaching one hundred and twenty, then one hundred and thirty-five degrees.

Tom woke up with a start. He felt as if he were inside a blazing furnace. He rolled over and saw Astro and Roger still asleep, sweat pouring off them in small rivulets. He started to wake them, but decided against it and just lay still under the thin sheet of space cloth that protected him from the sun. As light as the fabric square was, weighing no more than a pound, under the intense heat of the sun it felt like a woolen blanket where it touched him. Astro rolled over and opened his eyes.

"What time is it, Tom?"

"Must be about noon. How do you feel?"

"I'm not sure yet. I had a dream." The big cadet rubbed his eyes and wiped the sweat from his forehead. "I dreamed I was being shoved into an oven—like Hansel and Gretel in that old fairy tale."

"Personally," mumbled Roger, without opening his eyes, "I'll take Hansel and Gretel. They might be a little more tender."

"I could do with a drink," said Astro, looking at Tom.

Tom hesitated. He felt that as hot as it was, it would get still hotter and there had to be strict control of the remainder of the water.

"Try to hold out a little longer, Astro," said Tom. "This heat hasn't really begun yet. You could drink the whole thing and still want more."

"That's right, Astro," said Roger, sitting up. "Best thing to do is just wet your tongue and lips a little. Drinking won't do much good now."

"O.K. by me," said Astro. "Well, what do we do now?"

"We sit here and we wait," answered Tom. He sat up and held the space cloth up on his side.

"You get in the middle, Astro," suggested Roger. "Your head is up higher than mine and Tom's. You can be the tent pole under this big top."

Astro grunted and changed places with the smaller cadet.

"Think there might be a breeze if we opened up one side of this thing?" asked Roger.

"If there was a breeze," answered Tom, "it'd be so hot, it'd be worse than what we've got inside."

"It sure is going to be a hot day," said Astro softly.

The thin fabric of the space cloth was enough to protect them from the direct rays of the sun, but offered very little protection against the heat. Soon the inside of the tent was boiling under the relentless sun.

They sat far apart, their knees pulled up, heads bowed. Once when the heat seemed unbearable, Tom opened one side of the cloth in a desperate hope that it might be a little cooler outside. A blast of hot air entered the makeshift tent and he quickly closed the opening.

About three o'clock Roger suddenly slipped backward and lay sprawled on the sand.

Tom opened one of the containers of water and dipped his shirttail into it. Astro watched him moisten Roger's lips and wipe his temples. In a few moments the cadet stirred and opened his eyes.

"I—I—don't know what happened," he said slowly. "Everything started swimming and then went black."

"You fainted," said Tom simply.

"What time is it?" asked Astro.

"Sun should be dropping soon now, in another couple of hours."

They were silent again. The sun continued its journey across the sky and at last began to slip behind the horizon. When the last red rays stretched across the sandy desert, the three cadets folded back the space-cloth covering and stood up. A soft evening breeze sprang up, refreshing them a little, and though none of them was hungry, each boy ate a light meal.

Tom opened the container of water again and measured out about an ounce apiece.

"Moisten your tongue, and sip it slowly," ordered Tom.

Roger and Astro took their share of the water and dipped fingers in it, wiping their lips and eyelids. They continued to do this until finally, no longer able to resist, they took the precious water and swished it around in their mouths before swallowing it.

They folded the space cloth, shouldered their packs, and after Tom had checked the compass, started their long march toward their plotted destination.

They had survived their first twenty-four hours in the barren wastes of the New Sahara, with each boy acutely aware that there was at least a week more of the same in front of them. The sky blackened, and soon after Deimos rose and started climbing across the dark sky.