It was just a hunch. Johnson knew that, but his hunches had often paid off in the past, and now he waited with a big man’s patience. For five hours he sat in the wooden stands, under the rumpled canvas the concessionaires had put up to protect the tourists from Marlock’s yellow sun.

The sun was hot and soon Johnson’s clothing was marked with large soiled patches of sweat. Now and then a light breeze blew across the stands from the native section and at each breath his nostrils crinkled in protest at the acrid smell.

Marlock wasn’t much of a planet. Its one claim to fame was its widely advertised Nature’s Moebius Strip. For eighteen months of the year--nine months of sub-zero cold, and nine months of sultry, sand-driven summer--the only outsiders to visit the planet came to buy its one export, the fur of the desert ox. But during the two months of fall and two months of spring the tourists poured in to gape at the Strip.

Idly, for the hundredth time, Johnson let his gaze run over the tourists lining up for their “thrill” journey out onto the Strip. Most of them wouldn’t go far; they only wanted to be able to say they’d been on it. They would build up some pretty exciting stories about it by the time they returned home.

There was no sign of Johnson’s man.

The party started out onto the Strip. At the first sensation of giddiness women squealed and most of them turned back. Their men came with them, secretly relieved at the excuse.

Johnson watched disinterestedly until only two remained: the young couple he had designated in his mind as honeymooners. The girl had grit. Perhaps more than the young fellow with her. He was affecting bored bravado, laughing loudly as the girl hesitated, but white streaks had appeared along his jawline and across his temples as he waited his turn.

The young couple had gone far enough out now so that they were in the first bend of the Strip’s twisting dip. Already their bodies were leaning sharply, as the mysterious gravity of the Strip held them perpendicular with their pathway. From where he sat Johnson could read nausea on their faces.

When they had followed the Strip around until they were leaning at a 35-degree angle, the girl seemed to lose her nerve. She stopped and stood gripping the guide rope with both hands. The boy said something to her, but she shook her head. He’d have to show his superiority now by going on, but it wouldn’t be for much farther, Johnson was willing to wager.

The boy took three more steps and paused. Then his body bent in the middle and he was sick. He’d had enough.

Both turned and hurried back. The crowd of tourists, watching or waiting their turn, cheered. In a few minutes, Johnson knew, the kid would be thinking of himself as a hero.

Suddenly Johnson straightened up, having spotted a new arrival, who gripped a tan brief-case tightly under one arm, buying a ticket. He had bulky shoulders and a black beard. Johnson’s man had come.

When he saw the bearded man go out with the next bunch to brave the Strip, Johnson rose and walked rapidly to the entrance. Elbowing his way through, with a murmured apology, he joined the waiting group.

A thin-faced odd-job man opened the rope gate and they shuffled through. The group must have walked fifty paces, with the bearded man well up in front and Johnson somewhere in the middle, before Johnson’s stomach sent him its first warning of unrest. Most of those ahead had stopped and Johnson threaded his way carefully past them.

Another twenty-five steps and he left the others behind. All except the bearded man. He neither paused nor looked back.

Johnson’s stomach had drawn up into a tight knot now, and his head was beginning to feel light. There was a faint ringing in his ears.

By the time he reached the end of the guide rope, nausea was creeping up from his stomach and into his throat. This was as far as it was supposed to be safe to go; the advertising literature had it that here was the point of no return. Up ahead his quarry was walking half doubled over, weaving back and forth, as though he were intoxicated. But he did not pause.

Johnson turned to look back, and felt his breakfast fighting to come up. From his perspective, the ground and the spectators watching him had swung to a position almost perpendicular to him. He felt that he was about to slide off into space. A wave of vertigo swept over him, his legs folded and he fell to the ground--sicker than he had ever been before in his life. Now he knew why the man ahead never looked back.

For a moment Johnson wondered whether he should give up. But, even as he debated, tenacity pulled him to his feet and forced him on.

And now something new was added to his vast discomfort. Tiny twinges of pain, like small electric shocks, began shooting up his legs, increasing in intensity with each step he took. The pain built up until the rusty taste of blood in his mouth told him that he had bitten into the flesh of his lower lip.

Johnson’s only consolation now was the thought that the man ahead of him must be suffering worse than he. At each step the pain increased its tempo, and the sound within his head grew to a battering roar. Although he felt himself at the last frayed ends of his vitality, he managed to stagger on.

Abruptly he realized that he had very nearly overtaken the man ahead. Through eyes glazed with pain, he saw the other, still standing, but swaying with agony and sickness. The man seemed to be gathering his resources for some supreme effort.

He tottered ahead two more steps, threw himself forward--and disappeared!

If he paused now, Johnson knew he would never be able to move again. Only will power and momentum carried him on. He stumbled and pitched forward. A searing pain traced a path through his head and he felt himself falling.

He was certain that he had never lost consciousness. The ground came up to meet him, and, with a last effort, he twisted his right shoulder inward. His cheek slid along the dirt and he lay on his side without strength. His legs pushed forward in a steady jerking movement as he fought to quiet his quivering muscles.

Gradually a soothing lethargy bathed Johnson’s body. His pains vanished, and the sickness left his stomach.

But something was wrong--terribly wrong!

Slowly he climbed to his feet and stood looking about him. He was still on the narrow arm of the Strip. On either side of him banks of white clouds, with the consistency of thick smoke, billowed and curled about the Strip--but somehow they left its pathway clear.

Johnson shook his head. The wrongness, he guessed, was in his own mind. But he was unable to determine what it was. Desperately he marshalled his scattered thoughts. Nothing. He took one groping step in the direction from which he had come--and staggered back from a wall of pain as tangible as a concrete structure.

He had no choice except to go forward. There was something he must do, he realized, but what was it? With the question came the answer to what was troubling him.

His memory was gone!

Or, at least, a great gap had been torn through it as though carved out by a giant blade. Briefly, despair threatened to overwhelm him.

“Hold it!” Johnson spoke aloud, and the words sobered him.

All fears became worse when not looked at. He had to bring this disaster out into the open where he could face it; where he could assay the damage. He had always taken pride in having a logical mind, with thought processes as clear and orderly as a bookkeeper’s ledger. Closing his eyes, he went swiftly over his recollections, placing each in its appropriate column.

When he finished he found the balance extremely unfavorable, but not hopeless. On the asset side he remembered: His name. Donald Johnson. Right now he was on Nature’s Moebius Strip, on the planet, Marlock. There was some man he had been following ... The rest was on the liability side of his balance sheet.

His name remained: All other memory of his own identity was gone. There was no recollection of his reason for being on Marlock, or whom he had been following or why. That left him little with which to work.

On the other hand, he mused, he might never be able to get off the Strip, so that didn’t matter much. He doubted his ability to stand the stress of penetrating that electric curtain again. His body had been able to take the punishment the first time because the force had built up gradually. Going back would be something else again.

Still he planned his next actions methodically--only in that way could he retain his sanity. He would go forward for one hour, he decided--he checked his wrist watch and discovered it had run down--and, if he found nothing, he would return and take his chances on getting through the curtain.

At the end of ten minutes he sighted land ahead of him. When he stepped off the Strip, he stopped in amazement!

Somehow the Strip had doubled back on itself, and he had returned to his starting place!

To his right was the rough wooden viewing platform, with its green umbrella gone. The stands were empty, and not a person--tourist or concessionaire--was in sight.

As Johnson stood, perplexed, he became aware of numbness spreading over his body. He brought up his hands and watched them slowly turn blue with cold. He realized then, in a burst of wonder, that winter had come to Marlock. Yet it had been spring when he had gone out on the Strip!

“Good God, man!” the clerk exclaimed. “Have you been out in that cold without a coat and hat? It must be thirty below.”

Johnson was unable to answer. He had run from the Strip--luckily he remembered its location in relation to the town--but it must have been over a mile to the hotel. Now, as he stamped his feet and beat at his sides with numbed hands, he breathed heavily, gasping great gulps of air into his tortured lungs.

“Come and warm yourself,” the clerk said, leading him over to a hot water radiator.

Johnson made no protest. He let the heat penetrate until it scorched the skin on his back. Only after the coldness left his body and was replaced by a drowsy inertia did his attention return to the clerk.

“Did you ever see me before?” Johnson asked.

The clerk shook his head. “Not that I know of.”

Any further investigation would have to wait until the next day, Johnson decided. He was dead tired, and he had to have some sleep. “Sign me up for a room, will you?” he asked.

Once up in his room, Johnson counted his money. One hundred and fifty-four credits. Enough to buy winter clothing and pay his room and board for a week. Maybe two. What would he do if he could learn nothing about himself before then?

The next day Johnson left the hotel to buy warm clothes. The town’s only store was a half-block down the street--as he remembered it, one of the big Interplanet Company stores.

Johnson waited until the storekeeper finished with two of the hairy-eared natives before giving his order. As he paid for the purchase, he asked: “Have you ever seen me before?”

The storekeeper glanced at him uneasily, and shifted his feet before answering. “Am I supposed to have?”

Johnson ignored the question. “Where can I find the manager?” he asked, slipping into the heavy coat the clerk held for him.

“Go up that stairway by the door,” the clerk said. “You’ll find him in his office.”

The manager was an old man. Old and black, with the deep blackness only an Earth-born Negro possesses. But his eyes retained their youthful alertness.

“Come in and sit down,” he told Johnson as he looked up and saw him standing in the doorway.

Johnson walked over and took the chair at the manager’s left. “I’ve had an accident,” he said, without preliminary, “and I seem to have lost my memory. Do you, by any chance, know who I am?”

“Never saw you before in my life,” the manager answered. “What’s your name?”

“Don Johnson.”

“Well, at least you remember something,” the old man said shrewdly. “You didn’t come during the last six months, if that’ll help any. There’ve been only two ships in that time. Both the Company’s. I meet all Company ships. If you came in during the tourist season I wouldn’t know.”

“Where else could I make inquiries?”

“Son,” the old man said kindly, “there’s three Earthmen on Marlock, that I know of--besides yourself, of course--the clerk at the hotel, my storekeeper, and myself. If you started asking questions at the hotel, you’re at the end of the line now.”

Something in Johnson’s expression caused the old man to go on. “How you fixed for money, son?”

Johnson drew a deep breath. “I’ve got enough to last me about two weeks.”

The manager hesitated, and carefully surveyed the ceiling with his eyes before he spoke again. “I’ve always felt we Earthmen should stick together,” he said. “If you want a job, I’ll find something for you to do and put you on the payroll.”

Twenty minutes later Johnson took the job--and twenty years later he was still working for the Company. He worked for them until...

Johnson was glad when the first twinge of fear came that it brought no panic. Instead it washed through his body, sharpening his reflexes and alerting his muscles for action.

He never ceased to wonder about this faculty he had acquired for sensing the presence of danger. There was no doubt in his mind that it had come into active function through the influence of his environment. But it must have been an intrinsic part of him even before that, waiting to be activated.

A moment before he had localized the source of his uneasiness--an Earthman, following perhaps fifty paces behind him. The one quick glance Johnson had allowed himself told him his follower was above average in height, and lean--with the wiry, muscular command of himself that marked him as a man capable of well-coordinated action.

He fought the rising force of the next “sand-blaster” boiling in from the desert, until he was unable to take a step against it. Then he moved behind a mud-packed arm projecting from the native dwelling at his right. Every building had one of these protecting arms added on; even the concrete buildings in the newer, Earth-built section of the city conformed to the custom. The sandstorms raged intermittently on Marlock through the entire nine month summer season, and could not be ignored, either by visitors or natives.

Johnson huddled against the projection, but the sand whipped around the corner and pounded at his back. Fine grains sifted through his clothing and mingled with the clammy sweat of his body. He resisted the frantic urge to scratch his itching, tormented skin, for he knew the flesh would be rubbed raw in a minute and increase the irritation to maddening proportions.

As the “sand-blaster” lost its intensity, he came out from his shelter and walked away as rapidly as the diminishing force of the wind would permit. If he could reach his office before his stalker closed in, he would be safe.

Suddenly a second Earthman, a short length of pipe in his right hand, came out of a doorway across the street and ran toward him.

Johnson realized that here was the source of the warning his intuition had sent--not the man behind him.

For a brief instant, he weighed the situation. The man was equipped for assault, but the chances were he was interested only in robbery. Johnson could probably save himself a beating by surrendering his money without resistance. He rejected the thought. A man had to live with his pride, and his self-respect; they were more necessary than physical well-being. Setting his shoulders firmly against the wall, he waited.

The man slowed to a walk when he saw his intended victim on guard. Johnson had the chance to observe him closely. He was a short and dark man, heavy of bone, with the lower half of his face thickly bearded, and sweat making a thin glistening film on his high cheekbones.

Abruptly a voice said, “I wouldn’t touch him if I were you.”

Johnson followed the gaze of his near-attacker to his left where the lean man he had noted before stood with a flat blue pistol pointed in their direction. He held the pistol like a man who knew how to use it.

“A gun!” the man in the street gasped. “Are you crazy?”

“Better put it away--fast,” Johnson warned his ally. “If the native police catch you with that gun, you’re in bad trouble.”

The lean man hesitated a moment, then shrugged and pocketed the gun. But he kept his hand in the pocket. “I can still use it,” he said, to no one in particular.

[Illustration]

“Look, chum,” the bearded thug grated. “You’re evidently a stranger here. Let me give you a tip. If you get caught using a gun, or even having one on you, the police’ll slap you in jail with an automatic sentence of ten years. An Earthman couldn’t stay alive in one of their so-called jails for a year.

“Now I’ve got a little business to attend to with Mr. Johnson, and I don’t want any interference. So be smart and run along.”

The smile never left the stranger’s face. “Right now,” he said, “I am interested in seeing that Mr. Johnson remains in good health. If you take another step toward him, I’ll shoot. And, if I’m not successful in evading the police afterwards, you won’t be alive to know it.”

“You’re bluffing,” the bearded man said. “I...”

“Let me point out something,” Johnson interrupted. “Suppose he is bluffing and doesn’t use the gun: The odds are still two to one against you. Are you sure you could handle both of us--even with the help of that pipe?”