"If we hit much more of this meteor flak we'll have to give up and go home," said Daren, frowning at the radar scope.

"What's the maximum size the hull can withstand?" This was from Doctor John Deegan, the thirty-seven-year-old astrophysicist, world-renowned despite his youth. A steady, even-tempered man and reliable scholar, just the type to stand up best under the strain of the responsibility, the unknown dangers, and the very close confinement of a ship that cost more than a thousand dollars for every precious pound she carried. He sat in his bunk now, bending over a collapsible plywood writing board, taking copious notes.

"I'd say up to a centimeter," said Ray Gilbert. The newspapers back on Earth were referring to him at that moment as young Doctor Raymond Gilbert, physicist, rocket specialist and ballistics expert, cheerful, capable, practical--possessing a mind that was as steady as a gyroscope. "Mean velocity is enough to give any meteors over that size sufficient mass to penetrate the hull."

"Okay," Deegan said. "Now, what is the mean velocity?"

"Roughly, that of Earth's orbital speed," Doctor Daren replied. "About eighteen miles per second. Of course, most of them are heading sunward and we're traveling toward the new moon, which puts the majority of them on our tail, and as we're hitting about ten miles per second, that still gives them an eight-mile-per-second mean velocity of impact. I wish we could stay on the moon until it's full, so that on our return trip we would enjoy the same advantage, but inasmuch as we're allowed only seventy-two hours there, we'll have to strike back in the face of this celestial flak, and the mean impact velocity against our hull will be about twenty-eight miles per second. This will reduce the minimum size and increase the danger of penetration. Putting it plainly, boys, I'd say we have only a slim chance of making it back at all. So far, we've tried not to think what would happen if a good-sized meteor hit us. Of course, radar and automatic correction helps to dodge most of the bad ones, but there are just too many meteors in outer space."

"It looks," said Deegan, "as though this first trip out here is going to be the last one for at least twenty years. More work is going to have to be done on the meteor problem. Maybe we'll have to conquer gravity, travel at lower speeds and develop super plating for the hulls."

"Whoa!" exclaimed Gilbert, flashing a smile at his companions. "For the gravity problem, tack on at least ten more years. Leave us not be visionary, Chum!

Doctor Daren did not smile. He spoke slowly and carefully, watching each man intently. "I'd say it would be at least fifty years before another man-carrying space ship will get out here," he said. "You forget that solar radiations and cosmic phenomena abound out here. Do you know what my instruments say?"

Deegan and Gilbert turned slightly pale as they stared back at the older scientist. And even Flannigan looked up from the periscope to listen.

"They say that we've bought a pretty expensive ticket for this trip, and that nobody else in the future is going to want to pay the same price." Daren's listeners knew it was costing the radiologist considerable effort to get out what he had to say.

"What is it, Henry?" asked Gilbert.

"Yes, we can take it!" put in Deegan.

Flannigan only sat there at the periscope and looked at Doctor Daren in silence. "I want you to understand," continued the latter, "that the instruments are not mistaken. The fact is, we've already been under sufficient radiation to make us completely sterile..."

This was followed by a long moment of silence. Deegan had two children. He only frowned and thought of Gilbert, who had just gotten married, and Flannigan, who was engaged to Daren's daughter Louise. Gilbert's mouth dropped agape in an obvious expression of chagrin, and beads of cold perspiration began to glisten on his forehead. He listened to the muffled "ping!" of tiny meteoric particles as they struck the outer surface of the ship, and he swallowed a great lump in his throat. Flannigan, however, was almost expressionless, except for a barely perceptible tightening of the muscles along his rugged jaws.

"Any reason for continuing onward?" asked Deegan, tonelessly.

Daren sighed, brushing kinky gray hair from his forehead and replied, "You know the amount of government money that's gone into this expedition. We're supposed to claim the moon in the name of the United Nations. That's the principal political objective. More important still, from the scientific point of view, is my radiation research. The instruments already contain priceless information. And there is more to be gained--much more. In fact, we'll have to send remote-controlled rockets out here later with new types of instruments to pick up new stuff I'm running across that we never knew existed in outer space, or anywhere, for that matter."

"There's your answer," said Gilbert. "Let the robot ships finish the job. I'm for going back while there's still a slim chance!"

"So am I," said Deegan.

Doctor Daren raised a quizzical eyebrow and looked at Flannigan, significantly. All three men looked at Flannigan. He was not the leader of the expedition, but he was the pilot, the only member who could handle the ship reliably when it came to take-offs and landings. He was a scientist in his own right, and likeable enough on the ground, but out here he had suddenly become as enigmatical as the multifaceted void of space itself. There was something about the space-flying Michael Flannigan that pointed him out as a marked man.

They could not see it in his tanned and rugged face, exactly, but under an unruly mop of jet-black hair, there beneath heavy, black brows, was an unusual pair of deep blue eyes. And there it could be seen. A wildness, a desperate restlessness, an almost supernatural longing for the indefinable. At times it had camouflaged itself behind a sort of silent and defiant laughter, but now, out here on the untraveled star road to Earth's far-flung satellite, out here where the mighty Unknown assailed the sanity of the mind and breathed sheer entity into their finite, human fears, they saw that this thing in Flannigan's eyes manifested itself in an expression of determination that defied all the agencies of Man and Nature to thwart it.

Flannigan grinned humorlessly as he replied to their unspoken question. "What was it Columbus said?"

"'Sail on! Sail on!'" quoted Deegan irritably. "But Columbus had a chance, and he was only wrestling with a few thousand miles of water. We're tweaking the nose of Fate itself, Mike! Be reasonable! I say we turn back!"

"That's two votes," said Flannigan. "What do you say, Doctor Daren?"

"I am an old man," replied Daren, with a sad but eloquent smile.

"Aren't we all!" retorted Gilbert bitterly. "Let's go back! What are we waiting for?"

"For Michael Flannigan," replied Deegan, and there was ice in his tone as he glared at the dark-browed Irish man.

Now Flannigan's jaw muscles popped out, hard and lumpy, under a day's growth of beard. He glared at all of them, with his broad back to the control board. Large, muscular hands gripped the panel board on either side of him in an unmistakable sign of possession. He was a powerful man, fully capable of manhandling any of them.

"Listen to me," he said. "The damage to us is done. We're sterile. No kids. No family. Okay. Now we know. But we're alive--and we're out here. It's a dangerous trip. We're risking our lives every second of it. So what! Did you expect a Cook's tour? What we're doing is the most important thing in history, and half a century may pass before it is tried again. We're in communication with Earth. We can tell them what we're finding out. That information alone is worth a hundred lives. And yet we may come out of this without another scratch. So I say we're going, to the moon!"

Doctor Daren might have been proud of his future son-in-law at that moment had he not been troubled by one curious impression. It was what the others felt, too, but could not explain: that Michael Flannigan wanted, more than anything in this life or any other life, to get to the moon, alive or half dead, with his companions or without them. One way or another, he had to get to the moon. Though why this was so they knew that even he could not have told them.

"Michael," said Daren, "I am the responsible leader of this expedition. Suppose I ordered you to return to Earth--now?"

Flannigan calmly met the menacing glare of Deegan and Gilbert. "We'd go to the moon," he answered, "and I'd risk the consequences."

Deegan stood up, clenching his fists. "That's mutiny!" he shouted.

"Not yet," put in Daren, raising his hand for silence. "I have not given him the order to return. I merely wanted to know where we stood. The fact of the matter is, I strongly recommend that we make the attempt. Let's continue onward."

Grudgingly, the two men turned back to their work. But Gilbert paused long enough to look fondly at a pinup girl on the wall beside his bunk, and his eyes grew red. It was his young wife.

Even if he did live through this, there would be no children...

Flannigan slept, for the first time since their take-off twenty-four hours before. And he dreamed, but it was not a dream that belonged to mortal man.

He was Gur. In his veins flowed the god blood, and he was mighty when Earth was still young.

It was Earth of eons past, before the great cataclysm. Only the beautiful little red people and the alien green men lived there then. The spiritual, fun-loving, music-loving red ones were indigenous to Earth. They were to leave their legend behind them--tales of the little folk, of fairies and leprechauns. The race of green men had come from the stars ages before and had forgotten how to traverse the void again. These were the troublemakers, the usurpers, who made live sacrifice of the red people to their cold stone gods.

But cataclysm threatened the solar system A large celestial body was approaching the sun, and earthquakes and deadly storms assailed the Earth. The red people and the green people turned to their gods and prayed.

Then he had come--Gur, Bringer of the Lens. Traveling afar in his ship, he had detected the plight of Earth. He had come to its people, a giant, shining god-man of powers and an intelligence beyond their understanding.

The sun would grow very hot, he told them. Its flames would melt the Earth and turn it into lava, and all life would be destroyed. Eons more would pass before the planet would see life again.

So he gave the red people the Lens, and they passed into it, to that other dimension and that great, endless world within, where they would be safe from the very heart of the hottest star--for the Lens was indestructible.

And the green men had come to Gur, laying down their bloodied weapons of war, saying to him that they would mend their ways and give the red men peace, if only Gur would permit them to live in the Land of the Lens.

And he had agreed, saying to them that they must obey one rule only and never break it. His single rule, given to both the red men and the green men, was that there should be peace and freedom forever. In return, they would enjoy security and eternal life, there in the hidden, secret country, the Land of the Lens. If they ever disobeyed his order, he or his son or his son's son, in future time, would return. And he would be called--the Avenger.

As the cataclysm struck, Gur, himself, entered the Lens, to sojourn for an eon or so with the peoples he had saved. While Earth softened, in the cauldron of celestial fire, into a wobbly ball of lava, the Lens remained inviolate, and life went on undisturbed within. Even when the changes occurring on Earth were so violent that a mighty piece of the planet flew away and became a satellite, bearing the Lens with it, the dwellers in the Land of the Lens knew it not. For there, on their two continents in the endless sea of their hidden world, life was secure and eternal.

Some there were who were killed by accident, on rare occasions, and infrequently a child was born, but most of the original settlers were still young when Gur prepared to leave them.

He did not wish to leave, for he had fallen in love with the fairest of the little women, queen of the red-skinned people. And she with him. Great was her sorrow in those days when she knew that Gur's time within the Lens was ended, and that for reasons she would never understand he had to travel onward in the Outer Emptiness, where the stars shone down on a new and flourishing Earth and on its cold and airless satellite, where lay the Lens.

Gur left the red men in possession of one continent in that secret world and the green men in possession of the other. He reminded them again of his command regarding peace and freedom, and then he left them, to be seen no more.

But Flannigan, in his dream, saw in the hidden land, on the continent of the red men, a vast desert, a desolate wilderness filled with an endless maze of barren ridges of bluish rock, like slate. These ridges formed unscalable walls, and anyone losing his way there would be lost forever. It was here the red men came when they had tired of twice ten thousand years or more of life. This was the Walk Alone, that led to eternal sleep. And here he saw Gur's loved one, the saddened queen of the red ones. It was she who walked there, alone. And he heard, not in his own mind, but in Gur's, the sound of tiny voices singing for him his own lament:

Whither has my lost love gone?

Altinra, she of laughter,

She whose eyes were like the dawn

Where night embraces day;

She who sings no more of me,

Who walks into Eternity,

Taking only memory

Of love, like blossoms, withered...

Flannigan awoke with a start, to find Daren wiping his face with a small towel from the first-aid chest. Deegan and Gilbert, pale-faced and bewhiskered, were looking over his shoulder in amazement.

"Good Lord, Michael!" exclaimed the elderly scientist. "You're perspiring enough to dissolve! What kind of nightmare was that? You've been muttering and groaning to yourself for hours!

Flannigan sat up, staring at his companions wide-eyed, like a madman.

"There's more!" he cried out in desperation, thinking of the song he had heard. "There's another part to it!"

"To what? Your dream? What was it?"

Flannigan shook his head to clear it. "I--I guess it was a dream," he said. "I'm going space batty."

Gilbert smiled wryly. "You have company," he said. "And we still have thirty-six hours to go!"