Lawton enjoyed a good fight. He stood happily trading blows with Slashaway Tommy, his lean-fleshed torso gleaming with sweat. He preferred to work the pugnacity out of himself slowly, to savor it as it ebbed.

“Better luck next time, Slashaway,” he said, and unlimbered a left hook that thudded against his opponent’s jaw with such violence that the big, hairy ape crumpled to the resin and rolled over on his back.

Lawton brushed a lock of rust-colored hair back from his brow and stared down at the limp figure lying on the descending stratoship’s slightly tilted athletic deck.

“Good work, Slashaway,” he said. “You’re primitive and beetle-browed, but you’ve got what it takes.”

Lawton flattered himself that he was the opposite of primitive. High in the sky he had predicted the weather for eight days running, with far more accuracy than he could have put into a punch.

They’d flash his report all over Earth in a couple of minutes now. From New York to London to Singapore and back. In half an hour he’d be donning street clothes and stepping out feeling darned good.

He had fulfilled his weekly obligation to society by manipulating meteorological instruments for forty-five minutes, high in the warm, upper stratosphere and worked off his pugnacity by knocking down a professional gym slugger. He would have a full, glorious week now to work off all his other drives.

The stratoship’s commander, Captain Forrester, had come up, and was staring at him reproachfully. “Dave, I don’t hold with the reforming Johnnies who want to re-make human nature from the ground up. But you’ve got to admit our generation knows how to keep things humming with a minimum of stress. We don’t have world wars now because we work off our pugnacity by sailing into gym sluggers eight or ten times a week. And since our romantic emotions can be taken care of by tactile television we’re not at the mercy of every brainless bit of fluff’s calculated ankle appeal.”

Lawton turned, and regarded him quizzically. “Don’t you suppose I realize that? You’d think I just blew in from Mars.”

“All right. We have the outlets, the safety valves. They are supposed to keep us civilized. But you don’t derive any benefit from them.”

“The heck I don’t. I exchange blows with Slashaway every time I board the Perseus. And as for women--well, there’s just one woman in the world for me, and I wouldn’t exchange her for all the Turkish images in the tactile broadcasts from Stamboul.”

“Yes, I know. But you work off your primitive emotions with too much gusto. Even a cast-iron gym slugger can bruise. That last blow was--brutal. Just because Slashaway gets thumped and thudded all over by the medical staff twice a week doesn’t mean he can take--”

The stratoship lurched suddenly. The deck heaved up under Lawton’s feet, hurling him against Captain Forrester and spinning both men around so that they seemed to be waltzing together across the ship. The still limp gym slugger slid downward, colliding with a corrugated metal bulkhead and sloshing back and forth like a wet mackerel.

A full minute passed before Lawton could put a stop to that. Even while careening he had been alive to Slashaway’s peril, and had tried to leap to his aid. But the ship’s steadily increasing gyrations had hurled him away from the skipper and against a massive vaulting horse, barking the flesh from his shins and spilling him with violence onto the deck.

He crawled now toward the prone gym slugger on his hands and knees, his temples thudding. The gyrations ceased an instant before he reached Slashaway’s side. With an effort he lifted the big man up, propped him against the bulkhead and shook him until his teeth rattled. “Slashaway,” he muttered. “Slashaway, old fellow.”

Slashaway opened blurred eyes, “Phew!” he muttered. “You sure socked me hard, sir.”

“You went out like a light,” explained Lawton gently. “A minute before the ship lurched.”

“The ship lurched, sir?”

“Something’s very wrong, Slashaway. The ship isn’t moving. There are no vibrations and--Slashaway, are you hurt? Your skull thumped against that bulkhead so hard I was afraid--”

“Naw, I’m okay. Whatd’ya mean, the ship ain’t moving? How could it stop?”

Lawton said. “I don’t know, Slashaway.” Helping the gym slugger to his feet he stared apprehensively about him. Captain Forrester was kneeling on the resin testing his hocks for sprains with splayed fingers, his features twitching.

“Hurt badly, sir?”

The Commander shook his head. “I don’t think so. Dave, we are twenty thousand feet up, so how in hell could we be stationary in space?”

“It’s all yours, skipper.”

“I must say you’re helpful.”

Forrester got painfully to his feet and limped toward the athletic compartment’s single quartz port--a small circle of radiance on a level with his eyes. As the port sloped downward at an angle of nearly sixty degrees all he could see was a diffuse glimmer until he wedged his brow in the observation visor and stared downward.

Lawton heard him suck in his breath sharply. “Well, sir?”

“There are thin cirrus clouds directly beneath us. They’re not moving.”

Lawton gasped, the sense of being in an impossible situation swelling to nightmare proportions within him. What could have happened?

Directly behind him, close to a bulkhead chronometer, which was clicking out the seconds with unabashed regularity, was a misty blue visiplate that merely had to be switched on to bring the pilots into view.

The Commander hobbled toward it, and manipulated a rheostat. The two pilots appeared side by side on the screen, sitting amidst a spidery network of dully gleaming pipe lines and nichrome humidification units. They had unbuttoned their high-altitude coats and their stratosphere helmets were resting on their knees. The Jablochoff candle light which flooded the pilot room accentuated the haggardness of their features, which were a sickly cadaverous hue.

The captain spoke directly into the visiplate. “What’s wrong with the ship?” he demanded. “Why aren’t we descending? Dawson, you do the talking!”

One of the pilots leaned tensely forward, his shoulders jerking. “We don’t know, sir. The rotaries went dead when the ship started gyrating. We can’t work the emergency torps and the temperature is rising.”

“But--it defies all logic,” Forrester muttered. “How could a metal ship weighing tons be suspended in the air like a balloon? It is stationary, but it is not buoyant. We seem in all respects to be frozen in.”

“The explanation may be simpler than you dream,” Lawton said. “When we’ve found the key.”

The Captain swung toward him. “Could you find the key, Dave?”

“I should like to try. It may be hidden somewhere on the ship, and then again, it may not be. But I should like to go over the ship with a fine-tooth comb, and then I should like to go over outside, thoroughly. Suppose you make me an emergency mate and give me a carte blanche, sir.”

Lawton got his carte blanche. For two hours he did nothing spectacular, but he went over every inch of the ship. He also lined up the crew and pumped them. The men were as completely in the dark as the pilots and the now completely recovered Slashaway, who was following Lawton about like a doting seal.

“You’re a right guy, sir. Another two or three cracks and my noggin would’ve split wide open.”

“But not like an eggshell, Slashaway. Pig iron develops fissures under terrific pounding but your cranium seems to be more like tempered steel. Slashaway, you won’t understand this, but I’ve got to talk to somebody and the Captain is too busy to listen.

“I went over the entire ship because I thought there might be a hidden source of buoyancy somewhere. It would take a lot of air bubbles to turn this ship into a balloon, but there are large vacuum chambers under the multiple series condensers in the engine room which conceivably could have sucked in a helium leakage from the carbon pile valves. And there are bulkhead porosities which could have clogged.”

“Yeah,” muttered Slashaway, scratching his head. “I see what you mean, sir.”

“It was no soap. There’s nothing inside the ship that could possibly keep us up. Therefore there must be something outside that isn’t air. We know there is air outside. We’ve stuck our heads out and sniffed it. And we’ve found out a curious thing.

“Along with the oxygen there is water vapor, but it isn’t H2O. It’s HO. A molecular arrangement like that occurs in the upper Solar atmosphere, but nowhere on Earth. And there’s a thin sprinkling of hydrocarbon molecules out there too. Hydrocarbon appears ordinarily as methane gas, but out there it rings up as CH. Methane is CH4. And there are also scandium oxide molecules making unfamiliar faces at us. And oxide of boron--with an equational limp.”

“Gee,” muttered Slashaway. “We’re up against it, eh?”

Lawton was squatting on his hams beside an emergency ‘chute opening on the deck of the Penguin’s weather observatory. He was letting down a spliced beryllium plumb line, his gaze riveted on the slowly turning horizontal drum of a windlass which contained more than two hundred feet of gleaming metal cordage.

Suddenly as he stared the drum stopped revolving. Lawton stiffened, a startled expression coming into his face. He had been playing a hunch that had seemed as insane, rationally considered, as his wild idea about the bulkhead porosities. For a moment he was stunned, unable to believe that he had struck pay dirt. The winch indicator stood at one hundred and three feet, giving him a rich, fruity yield of startlement.

One hundred feet below him the plummet rested on something solid that sustained it in space. Scarcely breathing, Lawton leaned over the windlass and stared downward. There was nothing visible between the ship and the fleecy clouds far below except a tiny black dot resting on vacancy and a thin beryllium plumb line ascending like an interrogation point from the dot to the ‘chute opening.

“You see something down there?” Slashaway asked.

Lawton moved back from the windlass, his brain whirling. “Slashaway there’s a solid surface directly beneath us, but it’s completely invisible.”

“You mean it’s like a frozen cloud, sir?”

“No, Slashaway. It doesn’t shimmer, or deflect light. Congealed water vapor would sink instantly to earth.”

“You think it’s all around us, sir?”

Lawton stared at Slashaway aghast. In his crude fumblings the gym slugger had ripped a hidden fear right out of his subconsciousness into the light.

“I don’t know, Slashaway,” he muttered. “I’ll get at that next.”

A half hour later Lawton sat beside the captain’s desk in the control room, his face drained of all color. He kept his gaze averted as he talked. A man who succeeds too well with an unpleasant task may develop a subconscious sense of guilt.

“Sir, we’re suspended inside a hollow sphere which resembles a huge, floating soap bubble. Before we ripped through it it must have had a plastic surface. But now the tear has apparently healed over, and the shell all around us is as resistant as steel. We’re completely bottled up, sir. I shot rocket leads in all directions to make certain.”

The expression on Forrester’s face sold mere amazement down the river. He could not have looked more startled if the nearer planets had yielded their secrets chillingly, and a super-race had appeared suddenly on Earth.

“Good God, Dave. Do you suppose something has happened to space?”

Lawton raised his eyes with a shudder. “Not necessarily, sir. Something has happened to us. We’re floating through the sky in a huge, invisible bubble of some sort, but we don’t know whether it has anything to do with space. It may be a meteorological phenomenon.”

“You say we’re floating?”

“We’re floating slowly westward. The clouds beneath us have been receding for fifteen or twenty minutes now.”

“Phew!” muttered Forrester. “That means we’ve got to--”

He broke off abruptly. The Perseus’ radio operator was standing in the doorway, distress and indecision in his gaze. “Our reception is extremely sporadic, sir,” he announced. “We can pick up a few of the stronger broadcasts, but our emergency signals haven’t been answered.”

“Keep trying,” Forrester ordered.

“Aye, aye, sir.”

The captain turned to Lawton. “Suppose we call it a bubble. Why are we suspended like this, immovably? Your rocket leads shot up, and the plumb line dropped one hundred feet. Why should the ship itself remain stationary?”

Lawton said: “The bubble must possess sufficient internal equilibrium to keep a big, heavy body suspended at its core. In other words, we must be suspended at the hub of converging energy lines.”

“You mean we’re surrounded by an electromagnetic field?”

Lawton frowned. “Not necessarily, sir. I’m simply pointing out that there must be an energy tug of some sort involved. Otherwise the ship would be resting on the inner surface of the bubble.”

Forrester nodded grimly. “We should be thankful, I suppose, that we can move about inside the ship. Dave, do you think a man could descend to the inner surface?”

“I’ve no doubt that a man could, sir. Shall I let myself down?”

“Absolutely not. Damn it, Dave, I need your energies inside the ship. I could wish for a less impulsive first officer, but a man in my predicament can’t be choosy.”

“Then what are your orders, sir?”

“Orders? Do I have to order you to think? Is working something out for yourself such a strain? We’re drifting straight toward the Atlantic Ocean. What do you propose to do about that?”

“I expect I’ll have to do my best, sir.”

Lawton’s “best” conflicted dynamically with the captain’s orders. Ten minutes later he was descending, hand over hand, on a swaying emergency ladder.

“Tough-fibered Davie goes down to look around,” he grumbled.

He was conscious that he was flirting with danger. The air outside was breathable, but would the diffuse, unorthodox gases injure his lungs? He didn’t know, couldn’t be sure. But he had to admit that he felt all right so far. He was seventy feet below the ship and not at all dizzy. When he looked down he could see the purple domed summits of mountains between gaps in the fleecy cloud blanket.

He couldn’t see the Atlantic Ocean--yet. He descended the last thirty feet with mounting confidence. At the end of the ladder he braced himself and let go.

He fell about six feet, landing on his rump on a spongy surface that bounced him back and forth. He was vaguely incredulous when he found himself sitting in the sky staring through his spread legs at clouds and mountains.

He took a deep breath. It struck him that the sensation of falling could be present without movement downward through space. He was beginning to experience such a sensation. His stomach twisted and his brain spun.

He was suddenly sorry he had tried this. It was so damnably unnerving he was afraid of losing all emotional control. He stared up, his eyes squinting against the sun. Far above him the gleaming, wedge-shaped bulk of the Perseus loomed colossally, blocking out a fifth of the sky.

Lowering his right hand he ran his fingers over the invisible surface beneath him. The surface felt rubbery, moist.

He got swayingly to his feet and made a perilous attempt to walk through the sky. Beneath his feet the mysterious surface crackled, and little sparks flew up about his legs. Abruptly he sat down again, his face ashen.

From the emergency ‘chute opening far above a massive head appeared. “You all right, sir,” Slashaway called, his voice vibrant with concern.

“Well, I--”

“You’d better come right up, sir. Captain’s orders.”

“All right,” Lawton shouted. “Let the ladder down another ten feet.”

Lawton ascended rapidly, resentment smouldering within him. What right had the skipper to interfere? He had passed the buck, hadn’t he?

Lawton got another bad jolt the instant he emerged through the ‘chute opening. Captain Forrester was leaning against a parachute rack gasping for breath, his face a livid hue.

Slashaway looked equally bad. His jaw muscles were twitching and he was tugging at the collar of his gym suit.