empirical useability."

"Ah, yes," said the man. "The Psychotechnic Institute."

Dalgetty nodded, wondering why he had jumped into such a lecture. Well, the more people who had some idea of the truth the better—though it wouldn't do for them to know the whole truth either. Not yet.

"The Institute trains so many for governmental posts and does so much advisory work," said the man, "that sometimes it looks almost as if it were quietly taking over the whole show."

Dalgetty shivered a little in the sunset breeze and wished he'd brought his cloak. He thought wearily, Here it is again. Here is the story they are spreading, not in blatant accusations, not all at once, but slowly and subtly, a whisper here, a hint there, a slanted news story, a supposedly dispassionate article.... Oh, yes, they know their applied semantics.

"Too many people fear such an outcome," he declared. "It just isn't true. The Institute is a private research organization with a Federal grant. Its records are open to anyone."

"All the records?" The man's face was vague in the gathering twilight.

Dalgetty thought he could make out a skeptically lifted brow. He didn't reply directly but said, "There's a foggy notion in the public mind that a group equipped with a complete science of man—which the Institute hasn't got by a long shot—could 'take over' at once and, by manipulations of some unspecified but frightfully subtle sort, rule the world. The theory is that if you know just what buttons to push and so on, men will do precisely as you wish without knowing that they're being guided. The theory happens to be pure jetwash."

"Oh, I don't know," said the man. "In general terms it sounds pretty plausible."

Dalgetty shook his head. "Suppose I were an engineer," he said, "and suppose I saw an avalanche coming down on me. I might know exactly what to do to stop it—where to plant my dynamite, where to build my concrete wall and so on. Only the knowledge wouldn't help me. I'd have neither the time nor the strength to use it.

"The situation is similar with regard to human dynamics, both mass and individual. It takes months or years to change a man's convictions and when you have hundreds of millions of men...." He shrugged. "Social currents are too large for all but the slightest, most gradual control. In fact perhaps the most valuable results obtained to date are not those which show what can be done but what cannot."

"You speak with the voice of authority," said the man.

"I'm a psychologist," said Dalgetty truthfully enough. He didn't add that he was also a subject, observer and guinea pig in one. "And I'm afraid I talk too much. Go from bad to voice."

"Ouch," said the man. He leaned his back against the rail and his shadowy hand extended a pack. "Smoke?"

"No, thanks, I don't."

"You're a rarity." The brief lighter-flare etched the stranger's face against the dusk.

"I've found other ways of relaxing."

"Good for you. By the way I'm a professor myself. English Litt at Colorado."

"Afraid I'm rather a roughneck in that respect," said Dalgetty. For a moment he had a sense of loss. His thought processes had become too far removed from the ordinary human for him to find much in fiction or poetry. But music, sculpture, painting—there was something else. He looked over the broad glimmering water, at the stations dark against the first stars, and savored the many symmetries and harmonies with a real pleasure. You needed senses like his before you could know what a lovely world this was.

"I'm on vacation now," said the man. Dalgetty did not reply in kind. After a moment—"You are too, I suppose?"

Dalgetty felt a slight shock. A personal question from a stranger—well, you didn't expect otherwise from someone like the girl Glenna but a professor should be better conditioned to privacy customs.

"Yes," he said shortly. "Just visiting."

"By the way, my name is Tyler, Harmon Tyler."

"Joe Thomson." Dalgetty shook hands with him.

"We might continue our conversation if you're going to be around for awhile," said Tyler. "You raised some interesting points."

Dalgetty considered. It would be worthwhile staying as long as Bancroft did, in the hope of learning some more. "I may be here a couple of days yet," he said.

"Good," said Tyler. He looked up at the sky. It was beginning to fill with stars. The deck was still empty. It ran around the dim upthrusting bulk of a weather-observation tower which was turned over to its automatics for the night and there was no one else to be seen. A few fluoros cast wan puddles of luminance on the plastic flooring.

Glancing at his watch, Tyler said casually, "It's about nineteen-thirty hours now. If you don't mind waiting till twenty hundred I can show you something interesting."

"What's that?"

"Ah, you'll be surprised." Tyler chuckled. "Not many people know about it. Now, getting back to that point you raised earlier...."

The half hour passed swiftly. Dalgetty did most of the talking.

"—and mass action. Look, to a rather crude first approximation a state of semantic equilibrium on a world-wide scale, which of course has never existed, would be represented by an equation of the form—"

"Excuse me." Tyler consulted the shining dial again. "If you don't mind stopping for a few minutes I'll show you that odd sight I was talking about."

"Eh? Oh-oh, sure."

Tyler threw away his cigarette. It was a tiny meteor in the gloom. He took Dalgetty's arm. They walked slowly around the weather tower.

The men came from the opposite side and met them halfway. Dalgetty had hardly seen them before he felt the sting in his chest.

A needle gun!

The world roared about him. He took a step forward, trying to scream, but his throat locked. The deck lifted up and hit him and his mind whirled toward darkness.

From somewhere will rose within him, trained reflexes worked, he summoned all that was left of his draining strength and fought the anesthetic. His wrestling with it was a groping in fog. Again and again he spiraled into unconsciousness and rose strangling. Dimly, through nightmare, he was aware of being carried. Once someone stopped the group in a corridor and asked what was wrong. The answer seemed to come from immensely far away. "I dunno. He passed out—just like that. We're taking him to a doctor."

There was a century spent going down some elevator. The boat-house walls trembled liquidly around him. He was carried aboard a large vessel, it was not visible through the gray mist. Some dulled portion of himself thought that this was obviously a private boat-house, since no one was trying to stop—trying to stop—trying to stop....

Then the night came.

III

He woke slowly, with a dry retch, and blinked his eyes open. Noise of air, he was flying, it must have been a triphibian they took him onto. He tried to force recovery but his mind was still too paralyzed.

"Here. Drink this."

Dalgetty took the glass and gulped thirstily. It was coolness and steadiness spreading through him. The vibratto within him faded, and the headache dulled enough to be endurable. Slowly he looked around, and felt the first crawl of panic.

No! He suppressed the emotion with an almost physical thrust. Now was the time for calm and quick wit and—

A big man near him nodded and stuck his head out the door. "He's okay now, I guess," he called. "Want to talk to him?"

Dalgetty's eyes roved the compartment. It was a rear cabin in a large airboat, luxuriously furnished with reclining seats and an inlaid table. A broad window looked out on the stairs.

Caught! It was pure bitterness, an impotent rage at himself. Walked right into their arms!

Tyler came into the room, followed by a pair of burly stone-faced men. He smiled. "Sorry," he murmured, "but you're playing out of your league, you know."

"Yeah." Dalgetty