Shuddering, he fought the thing off, his fingers closing on wiry fur as he caught and squeezed. The thing went limp, and suddenly melted in his hands. He heard it splash as it struck the damp ground at his feet.

_What were they doing to his mind?_

He screamed out in horror, and followed the echoes of his own scream as he ran down the stone corridor, blindly, slipping on the wet stone floor, falling on his knees into inches of brackish water, sc.r.a.ping back to his feet with an uncontrollable convulsion of fear and loathing, only to run more--

The corridor suddenly broke into two and he stopped short. He didn't know how far, or how long, he had run, but it suddenly occurred to him that he was still alive, still safe. Only his mind was under attack, only his mind was afraid, teetering on the edge of control. And this maze of dungeon tunnels--where could such a thing exist, so perfectly outfitted to horrify him, so neatly fitting into his own pattern of childhood fears and terrors; from where could such a _very individual_ attack on his sanity have sprung? From nowhere except....

_Except from his own mind!_

For an instant, he saw a flicker of light, thought he grasped the edge of a concept previously obscure to him. He stared around him, at the mist swirling down the damp, dark corridor, and thought of the rat that had melted in his hand. Suddenly, his mind was afire, searching through his experience with the strange not-men he had learned to detect, trying to remember everything he had learned and deduced about them before they began their brutal persecution.

They were men, and they looked like men, but they were different. They had other properties of mind, other capabilities that men did not have.

They were not-men. They could exist, and co-exist, two people in one frame, one person known, realized by all who saw, the other one concealed except from those who learned how to look. They could use their minds; they could rationalize correctly; they could use their curious four-dimensional knowledge to bring them to answers no three-dimensional man could reach.

_But they couldn't project into men's minds!_

Carefully, Harry peered down the misty tunnels. They were clever, these creatures, and powerful. Since they had discovered that he knew them, they had done their work of fear and terror on his mind skillfully. But they were limited, too; they couldn't make things happen that were not true--fantasies, illusions....

Yes, this dungeon was an illusion. It _had_ to be.

He cursed and started down the right-hand corridor, his heart sinking.

There was no such place and he knew it. He was walking in a dream, a fantasy that had no substance, that could do no more than frighten him, drive him insane; yet he must already have lost his mind to be accepting such an illusion.

Why had he delayed? Why hadn't he gone to the Hoffman Center, laid the whole story before Dr. Webber and Dr. Manelli at the very first, told them what he had found? True, they might have thought him insane, but they wouldn't have put him to torture. They might even have believed him enough to investigate what he told them, and then the cat would have been out of the bag. The tale would have been incredible, but at least his mind would have been safe.

He turned down another corridor and walked suddenly into waist-deep water, so cold it numbed his legs. He stopped again to force back the tendrils of unreasoning horror that brushed his mind. Nothing could really harm him. He would merely wait until his mind finally reached a balance again. There might be no end; it might be a ghastly trap, but he would wait.

Strangely, the mist was becoming greenish in color as it swirled toward him in the damp vaulted pa.s.sageway. His eyes began watering a little and the lining of his nose started to burn. He stopped short, newly alarmed, and stared at the walls, rubbing the tears away to clear his vision. The greenish-yellow haze grew thicker, catching his eyes and burning like a thousand furies, ripping into his throat until he was choking and coughing, as though great knives sliced through his lungs.

He tried to scream, and started running, blindly. Each gasping breath was an agony as the blistering gas dug deeper and deeper into his lungs.

Reason departed from him; he was screaming incoherently as he stumbled up a stony ramp, crashed into a wall, spun around and smashed blindly into another. Then something caught at his shirt.

He felt the heavy planks and pounded iron scrollwork of a huge door, and threw himself upon it, wrenching at the old latch until the door swung open with a screech of rusty hinges. He fell forward on his face, and the door swung shut behind him.

He lay face down, panting and sobbing in the stillness.

Coa.r.s.e hands grasped his collar, jerking him rudely to his feet, and he opened his eyes. Across the dim, vaulted room he could see the shadowy form of a man, a big man, with a broad chest and powerful shoulders, a man whose rich voice Harry almost recognized, but whose face was deep in shadow. As Harry wiped the tears from his tortured eyes, he heard the man's voice rumble out at him:

"Perhaps you've had enough now to change your mind about telling us the truth."

Harry stared, not quite comprehending. "The--the truth?"

The man's voice was harsh, cutting across the room impatiently. "The truth, I said. The problem, you fool, what you saw, what you learned; you know perfectly well what I'm referring to. But we'll swallow no more of this silly four-dimensional superman tale, so don't bother to start it."

"I--I don't understand you. It's--it's true--" Again he tried to peer across the room. "Why are you hunting me like this? What are you trying to do to me?"

"We want the truth. We want to know what you saw."

"But--but _you're_ what I saw. You know what I found out. I mean--" He stopped, his face going white. His hand went to his mouth, and he stared still harder. "Who are you?" he whispered.

"The truth!" the man roared. "You'd better be quick, or you'll be back in the corridor."

"_Webber!_"

"Your last chance, Harry."

Without warning, Harry was across the room, flying across the desk, crashing into the big man's chest. With a scream of fury he fought, driving his fists into the powerful chest, wrenching at the thick, flailing arms of the startled man.

"_It's you!_" he screamed. "It's you that's been torturing me. It's you that's been hunting me down all this time, not the other people, you and your crowd of ghouls have been at my throat!"

He threw the big man off balance, dropped heavily on him as he fell back to the ground, glared down into the other's angry brown eyes.

And then, as though he had never been there at all, the big man vanished, and Harry sat back on the floor, his whole body shaking with frustrated sobs as his mind twisted in anguish.

He had been wrong, completely wrong, ever since he had discovered the not-men. Because he had thought _they_ had been the ones who hunted and tortured him for so long. And now he knew how far he had been wrong. For the face of the shadowy man, the man behind the nightmare he was living, was the face of Dr. George Webber.

"You're a fool," said Dr. Manelli sharply, as he turned away from the sleeping figure on the bed to face the older man. "Of all the ridiculous things, to let him connect you with this!" The young doctor turned abruptly and sank down in a chair, glowering at Dr. Webber. "You haven't gotten to first base yet, but you've just given Scott enough evidence to free himself from integrator control altogether, if he gives it any thought. But I suppose you realize that."

"Nonsense," Dr. Webber retorted. "He had enough information to do that when we first started. I'm no more worried now than I was then. I'm sure he doesn't know enough about the psycho-integrator to be able voluntarily to control the patient-operator relationship to any degree.

Oh, no, he's safe enough. But you've missed the whole point of that little interview." Dr. Webber grinned at Manelli.

"I'm afraid I have. It looked to me like useless bravado."

"The persecution, man, the _persecution_! He's shifted his sights!

Before that interview, the _not-men_ were torturing him, remember?

Because they were afraid he would report his findings to me, of course.

But now it's _I_ that's against him." The grin widened. "You see where that leads?"

"You're talking almost as though you believed this story about a different sort of people among us."

Dr. Webber shrugged. "Perhaps I do."

"Oh, come now, George."

Dr. Webber's eyebrows went up and the grin disappeared from his face.

"Harry Scott believes it, Frank. We mustn't forget that, or miss its significance. Before Harry started this investigation of his, he wouldn't have paid any attention to such nonsense. But he believes it now."

"But Harry Scott is insane. You said it yourself."

"Ah, yes," said Dr. Webber. "Insane. Just like the others who started to get somewhere along those lines of investigation. Try to a.n.a.lyze the growing incidence of insanity in the population and you yourself go insane. You've got to be crazy to be a psychiatrist. It's an old joke, but it isn't very funny any more. And it's too much for coincidence.

"And then consider the nature of the insanity--a full-blown paranoia--oh, it's amazing. A cunning organization of men who are _not_-men, a regular fairy story, all straight from Harry Scott's agile young mind. But now it's _we_ who are persecuting him, _and he still believes his fairy tale_."

"So?"