How does one set up A barrier against mental attack? Lucky had the desire to resist, but there were no muscles he could flex, no guard he could throw up, no way he could return violence. He must merely remain as he was, resisting all those impulses that flooded his mind which he could not surely tell to be his own.

And how could he tell which were his own? What did he himself wish to do? What did he himself wish most to do?

Nothing entered his mind. It was blank. Surely there had to be something. He had not come up here without a plan.

Up here?

Then he had come up. Originally, he had been down.

Far down in the recesses of his mind, he thought, That's it.

He was in a ship. It had come up from the sea bottom. It was on the surface of the water now. Good. What next?

Why at the surface? Dimly he could remember it was safer underneath.

He bent his head with great difficulty, closed his eyes and opened them again. His thoughts were very thick.

He had to get word somewhere... somewhere... about something.

He had to get word.

Get word.

And he broke through! It was as though somewhere miles inside of himself he had put a straining shoulder to a door and it had burst open. There was a clear flash of purpose, and he remembered something he had forgotten.

Ship's radio and the space station, of course.

He said, huskily, "You haven't got me. Do you hear that? I remember, and I'll keep on remembering."

There was no answer.

He shouted aloud, incoherently. His mind was faintly occupied with the analogy of a man fighting an overdose of a sleeping drug. Keep the muscles active, he thought. Keep walking. Keep walking.

In his case, he had to keep his mind active, he had to keep the mental fibers working. Do something. Do something. Stop, and they'll get you.

He continued shouting, and sound became words, "I'll do-it. I'll do it." Do what? He could feel it slipping from him again.

Feverishly, he repeated to himself, "Radio to station... radio to station..." but the sounds were becoming meaningless.

He was moving now. His body turned clumsily as though his joints were wood and nailed in place, but it was turning. He faced the radio. He saw it clearly for a moment, then it wavered and became foggy. He bent his mind to the task, and it was clear again. He could see the transmitter, see the range-setting toggle and the frequency condensers. He could recall and understand its workings.

He took a dragging step toward it and a sensation as of red-hot spikes boring into his temples overwhelmed him.

He staggered and fell to his knees, then, in agony, rose again.

Through pain-hazed eyes, he could still make out the radio. First one of his legs moved, then another.

The radio seemed a hundred yards away, hazy, surrounded by a bloody mist. The pounding in Lucky's head increased with each step.

He fought to ignore the pain, to see only the radio, to think only of the radio. He forced his legs to move against a rubbery resistance that was entangling them and dragging him down.

Finally, he put out his arm, and when his fingers were still six inches away from the ultrawave, Lucky knew that his endurance was at an end. Try as he might, he could drive his exhausted body no closer. It was all over. It was ended.

The Hilda was a scene of paralysis. Evans lay unconscious on his cot; Bigman was crumpled on the floor; and though Lucky remained stubbornly upright, his trembling fingertips were the only sign of life in him.

The cold voice in Lucky's mind sounded once again in its even, inexorable monotone: "You are helpless, but you will not lose consciousness as did your companions. You will suffer this pain until you decide to submerge your ship, tell us what we wish to know, and end your life. We can wait patiently. There is no way you can resist us. There is no way you can fight us. No bribe! No threat!"

Lucky, through the endless torture, felt a striving within his sluggish, pain-soaked mind, the stirring of something new.

No bribe? No threat?

No bribe?

Even through the misty semiconsciousness, the spark in his mind caught fire.

He abandoned the radio, turned his thoughts away, and instantly the curtain of pain lifted a fraction. Lucky took a faltering step away from the radio, and it lifted a bit more. He turned away completely.

Lucky tried not to think. He tried to act automatically and without foreplanning. They were concentrating on preventing his reaching the radio. They must not realize the other danger they faced. The pitiless enemy must not deduce his intentions and try to stop him. He would have to act quickly. They must not stop him.

They must not!

He had reached the first-aid wall chest and flung open its door. He could not see clearly, and he lost precious seconds in fumbling.

The voice said, "What is your decision?" and the fierceness of pain began to clamp down upon the young councilman once more.

Lucky had it-a squat jar of bluish silicone. His fingers groped through what seemed deadening cotton for the little catch that would shut off the paramagnetic microfield that held the jar's lid closed and airtight.

He scarcely felt the little nudge as one fingernail caught the catch. He scarcely saw the lid move to one side and fall off. He scarcely heard it hit the floor with the sound of metastic against metal. Fuzzily, he could see that the jar was open, and hazily, he lifted bis arm toward the trash ejector.

The pain had returned in all its fury.

His left arm had lifted the hinged opening of the ejector; his right arm tremblingly raised the precious jar to the six-inch opening.

His arm moved for an eternity. He could no longer see. A red haze covered everything.

He felt his arm and the jar it held strike the wall. He pushed, but it would move no farther. The fingers on his left hand inched down from where they held the opening of the trash ejector, and touched the jar.

He daren't drop it now. If he did, he would never in his life find the strength to pick it up again.

He had it in both hands, and together both hands pulled at it. It inched upward, while Lucky hovered closer and closer to the edge of unconsciousness.

A nd then the jar was gone!

A million miles away, it seemed, he could hear the whistle of compressed air, and he knew the jar had been ejected into the warm Venusian ocean.

For a moment the pain wavered and then, in one giant stroke, lifted completely.

Lucky righted himself carefully and stepped away from the wall. His face and body were drenched in perspiration, and his mind still reeled.

As fast as his still faltering steps could take him, he moved to the radio transmitter, and this time nothing stopped him.

Evans sat in a chair with his head buried in his arms. He had gulped thirstily at water and kept saying over and over again, "I don't remember a thing. I don't remember a thing."

Bigman, bare to the waist, was mopping at his head and chest with a damp cloth, and a shaky grin carne to his face. "I do. I remember everything. One minute I was standing there listening to you talking to the voice, Lucky, and then with no warning I was flat on the floor. I couldn't feel a thing, I couldn't turn my head, I couldn't even blink my eyes, but I could hear everything that was going on. I could hear the voice and what you said, Lucky. I saw you start for the radio..."

He puffed his breath out and shook his head.

"I never made it that first time, you know," said Lucky quietly.

"I couldn't tell. You passed out of my field of vision, and after that all I could do was lie there and wait to hear you start sending. Nothing happened, and I kept thinking they must have you, too. In my mind, I could see all three of us lying in living death. It was all over, and I couldn't nudge a thumbnail. It was all I could do just to breathe. Then you moved back past my eyes again, and I wanted to laugh and cry and yell all at tht same time, but all I could do was lie there. I could just about make you out, Lucky, clawing at the wall. I couldn't tell what on Venus you were doing, but a few minutes later it was all over. Wow!"

Evans said wearily, "And we're really heading back for Aphrodite now, Lucky? No mistake?"

"We're heading back unless the instruments are lying, and I don't think they are," said Lucky. "When we do get back and we can spare the time, we'll all of us get a little medical attention."

"Sleep!" insisted Bigman. "That's all I want. Just two days of solid sleep."

"You'll get that, too," said Lucky.

But Evans, more than the other two, was haunted by the experience. It showed quite plainly in the way he huddled in his own arms and slouched, almost cowered, in his chair. He said, "Aren't they interfering with us in any way at all any more?" There was the lightest emphasis on the word they.

"I can't guarantee that," said Lucky, "but the worst of the affair is over in a way. I reached the space station."

"You're sure? There's no mistake?"

"None at all. They even relayed me to Earth and I spoke to Conway directly. That part is settled."

"Then it's all settled," crowed Bigman joyously. "Earth is prepared. It knows the truth about the V-frogs."

Lucky smiled, but offered no comment.

Bigman said, "Just one thing, Lucky. Tell me what happened. How did you break their hold? Sands of Mars! What did you do?"

Lucky said, "Nothing that I ought not to have thought of long hi advance and saved us all a great deal of needless trouble. The voice told us that all they needed in life was to live and to think. You recall that, Bigman? It said later on that we had no way of threatening them and no way of bribing them? It was only at the last moment that I realized you and I knew better."

"I know better?" said Bigman blankly.

"Certainly you do. You found out two minutes after you saw your first V-frog, that life and thought is not all they need. I told you on the way to the surface that Venusian plants stored oxygen so that Venusian animals got their oxygen from their food and didn't have to breathe. In fact, I said, they probably get too much oxygen and that's why they're so fond of low-oxygen food like hydrocarbons. Like axle grease, for instance. Don't you remember?"

Bigman's eyes were widening. "Sure."

"Just think how they must crave hydrocarbon. It must be like the craving of a child for candy."

Bigman said once again, "Sure."

"Now the V-frogs had us under mental control, but to maintain us under such control, they had to concentrate. What I had to do was distract them, at least to distract those that were nearest the ship, and whose power over us was strongest. So I threw out the obvious thing."

"But what? Don't play cute, Lucky."

"I threw out an open jar of petroleum jelly, which I got out of the medicine cabinet. It's pure hydrocarbon, of much higher grade than the axle grease. They couldn't resist. Even with so much at stake, they couldn't resist. Those nearest to the jar dived for it. Others farther away were in mental rapport, and their minds turned instantly to hydrocarbon. They lost control of us, and I was able to put through the call. That was all."

"Well, then," said Evans, "we're through with them."

"If it comes to that," said Lucky, "I'm not at all certain. There are a few things..."

He turned away, frowning, his lips clamped shut, as though he had already spoken too much.

The dome glimmered gorgeously outside the port, and Bigman felt his heart lift at the sight. He had eaten, even napped a bit, and his ebullient spirits bubbled as ever now. Lou Evans had recovered considerably from his own despondency. Only Lucky had not lost his look of wariness.

Bigman said, "I tell you the V-frogs are demoralized, Lucky. Look here, we've come back through a hundred miles of ocean, nearly, and they haven't touched us once. Well, have they?"

Lucky said, "Right now, I'm wondering why we don't get an answer from the dome."

Evans frowned in his turn. "They shouldn't take this long."

Bigman looked from one to the other. "You don't think anything can be wrong inside the city, do you?"

Lucky waved his hand for silence. A voice came in over the receiver, low and rapid.

"Identification, please."

Lucky said, "This is the Council-chartered subship Hilda, out of Aphrodite, returning to Aphrodite. David Starr in charge and speaking."

"You will have to wait."

"For what reason, please?"

"The locks are all in operation in the moment."

Evans frowned and muttered, "That's impossible, Lucky."

Lucky said, "When will one be free? Give me its location, and direct me to its vicinity by ultrasignal."

"You will have to wait."

The connection remained open, but the man at the other end spoke no more.

Bigman said indignantly, "Get Councilman Morriss, Lucky. That'll get some action."

Evans said hesitantly, "Morriss thinks I'm a traitor. Do you suppose he could have decided that you've thrown in with me, Lucky?"

"If so," said Lucky, "he'd be anxious to get us into the city. No, it's my thought that the man we've been speaking to is under mental control."

Evans said, "To stop us from getting in? Are you serious?"

"I'm serious."

"There's no way they can stop us from getting hi in

the long run unless they..." Evans paled and moved

to the porthole in two rapid strides. "Lucky, you're right! They're bringing a cannon blaster to bear! They're going to blow us out of the water!"

Bigman was at the porthole, too. There was no mistake about it. A section of the dome had moved to one side, and through it, somewhat unreal as seen through water, was a squat tube.

Bigman watched the muzzle lower and center upon, them, with fascinated horror. The Hilda was unarmed. It could never gain velocity fast enough to escape being blasted. There seemed no way out of instant death.