"One minute." Diktor stepped behind the raised dais. His head ap­peared above the side a moment later. "I've set the controls. Okay. Go!"

Bob Wilson stepped through the locus known as the Time Gate. There was no particular sensation connected with the transition. It was like stepping through a curtained doorway into a darker room. He paused for a moment on the other side and let his eyes adjust to the dimmer light. He was, he saw, indeed in his own room.

There was a man in it, seated at his own desk. Diktor had been right about that. This, then, was the chap he was to send back through the Gate. Diktor had said he would recognize him. Well, let's see who it is.

He felt a passing resentment at finding someone at his desk in his room, then thought better of it. After all, it was just a rented room; when he disappeared, no doubt it had been rented again. He had no way of telling how long he had been gone—shucks, it might be the middle of next week! The chap did look vaguely familiar, although all he could see was his back. Who was it? Should he speak to him, cause him to turn around? He felt vaguely reluctant to do so until he knew who it was. He rational­ized the feeling by telling himself that it was desirable to know with whom he was dealing before he attempted anything as outlandish as persuading this man to go through the Gate.

The man at the desk continued typing, paused to snuff out a cigarette by laying it in an ash tray, then stamping it with a paper weight.

Bob Wilson knew that gesture.

Chills trickled down his back. "If he lights his next one," he whispered to himself, "the way I think he is going to—"

The man at the desk took out another cigarette, tamped it on one end, turned it and tamped the other, straightened and crimped the paper on one end carefully against his left thumbnail and placed that end in his mouth.

Wilson felt the blood beating in his neck. Sitting there with his back to him was himself, Bob Wilson!

He felt that he was going to faint. He closed his eyes and steadied himself on a chair back. "I knew it," he thought, "the whole thing is absurd. I'm crazy. I know I'm crazy. Some sort of split personality. I shouldn't have worked so hard."

The sound of typing continued.

He pulled himself together, and reconsidered the matter. Diktor had warned him that he was due for a shock, a shock that could not be explained ahead of time, because it could not be believed. "All right— suppose I'm not crazy. If time travel can happen at all, there is no reason why I can't come back and see myself doing something I did in the past. If I'm sane, that is what I'm doing.

"And if I am crazy, it doesn't make a damn bit of difference what I do!

"And furthermore," he added to himself, "if I'm crazy, maybe I can stay crazy and go back through the Gate! No, that does not make sense. Neither does anything else—the hell with it!"

He crept forward softly and peered over the shoulder of his double. "Duration is an attribute of the consciousness," he read, "and not of the plenum."

"That tears it," he thought, "right back where I started, and watching myself write my thesis."

The typing continued. "It has no Ding an Sich. Therefore—" A key stuck, and others piled up on top of it. His double at the desk swore and reached out a hand to straighten the keys.

"Don't bother with it," Wilson said on sudden impulse. "It's a lot of utter hogwash anyhow."

The other Bob Wilson sat up with a jerk, then looked slowly around. An expression of surprise gave way to annoyance. "What the devil are you doing in my room?" he demanded. Without waiting for an answer he got up, went quickly to the door and examined the lock. "How did you get in?"

"This," thought Wilson, "is going to be difficult."

"Through that," Wilson answered, pointing to the Time Gate. His double looked where he had pointed, did a double take, then advanced cautiously and started to touch it.

"Don't!" yelled Wilson.

The other checked himself. "Why not?" he demanded.

Just why he must not permit his other self to touch the Gate was not clear to Wilson, but he had had an unmistakable feeling of impending disaster when he saw it about to happen. He temporized by saying, "I'll explain. But let's have a drink." A drink was a good idea in any case. There had never been a time when he needed one more than he did right now. Quite automatically he went to his usual cache of liquor in the wardrobe and took out the bottle he expected to find there.

"Hey!" protested the other. "What are you doing there? That's my liquor."

"Your liquor—" Hell's bells! It was his liquor. No, it wasn't; it was— their liquor. Oh, the devil! It was much too mixed up to try to explain. "Sorry. You don't mind if I have a drink, do you?"

"I suppose not," his double said grudgingly. "Pour me one while you're about it."

"Okay," Wilson assented, "then I'll explain." It was going to be much, much too difficult to explain until he had had a drink, he felt. As it was, he couldn't explain it fully to himself.

"It had better be good," the other warned him, and looked Wilson over carefully while he drank his drink.

Wilson watched his younger self scrutinizing him with confused and almost insupportable emotions. Couldn't the stupid fool recognize his own face when he saw it in front of him? If he could not see what the situation was, how in the world was he ever going to make it clear to him? It had slipped his mind that his face was barely recognizable in any case, being decidedly battered and unshaven. Even more important, he failed to take into account the fact that a person does not look at his own face, even in mirrors, in the same frame of mind with which he regards an­other's face. No sane person ever expects to see his own face hanging on another.

Wilson could see that his companion was puzzled by his appearance, but it was equally clear that no recognition took place. "Who are you?" the other man asked suddenly.

"Me?" replied Wilson. "Don't you recognize me?"

"I'm not sure. Have I ever seen you before?"

"Well—not exactly," Wilson stalled. How did you go about telling another guy that the two of you were a trifle closer than twins? "Skip it—you wouldn't know about it."

"What's your name?"

"My name? Uh—" Oh, oh! This was going to be sticky! The whole situation was utterly ridiculous. He opened his mouth, tried to form the words "Bob Wilson," then gave up with a feeling of utter futility. Like many a man before him, he found himself forced into a lie because the truth simply would not be believed. "Just call me Joe," he finished lamely.

He felt suddenly startled at his own words. It was at this point that he realized that he was in fact, "Joe," the Joe whom he had encountered once before. That he had landed back in his own room at the very time at which he had ceased working on his thesis he already realized, but he had not had time to think the matter through. Hearing himself refer to himself as Joe slapped him in the face with the realization that this was not simply a similar scene, but the same scene he had lived through once before—save that he was living through it from a different viewpoint.

At least he thought it was the same scene. Did it differ in any respect? He could not be sure as he could not recall, word for word, what the conversation had been.

For a complete transcript of the scene that lay dormant in his memory he felt willing to pay twenty-five dollars cash, plus sales tax.

Wait a minute now—he was under no compulsion. He was sure of that. Everything he did and said was the result of his own free will. Even if he couldn't remember the script, there were some things he knew "Joe" hadn't said. "Mary had a little lamb," for example. He would recite a nursery rhyme and get off this damned repetitious treadmill. He opened his mouth— "Okay, Joe Whatever-your-name-is," his alter ego remarked, setting down a glass which had contained, until recently, a quarter pint of gin, "trot out that explanation and make it snappy."