At first I thought it was just another wrong number. Well, it was, in a sense—but not the kind of wrong number I thought it was. The ringing signal burred against my ear in the usual way, then there was a click, and somebody said, "Office of Historical Research. Zon Twenty speaking."

"Oh. 'Scuse me," I said. "I must have dialed wrong."

That was euphemism—misplaced loyalty, maybe. I didn't dial the wrong number, and I knew it. But high brass had installed a new automatic dialing system in the Pentagon as an economy measure, and it produced so many wrong numbers and entanglements that I think it actually must have cost more money in the long run than the old-fashioned live operator system—but then that shouldn't surprise you if you've ever been connected with the military.

I was about to hang up after my apology. The voice on the other end said: "Wait! Did you say—dialed?"

"Sure," I said.

"Then—" and he seemed surprised, if not downright startled—"what kind of a phone are you speaking from?"

"Huh?" I said. "What kind? The regular kind. Phone, desk, dial, M-1—or whatever the Army calls it."

This time his voice went off like a small bomb. "The Army?" he said.

"Sure," I said. "What's the matter with the Army?"

And thought: Navy or Air Force type, no doubt. Our allies. Have to put up with them in the Pentagon. Have to put up with a lot of things—even being Colonel Lawrence Boggs didn't save you from a snafu dialling system. I thought: somebody is out to needle armchair colonels this week. I'll play around with it for a while, maybe find out who's got the sense of humor.

The voice said, "Look here, are you joking with me?"

"Perish it," I said.

"But this talk about—about dial phones. About armies. Why, you sound like one of those historical tri-vids about the twentieth century!"

I smiled, without too much humor, shook my head at the phone, and said, "Look, fellow, come off it, will you? I haven't got time to play games." I hoped he wasn't some general or equivalent rank in a pixie mood.

"Wait!" he said. "Wait—please—don't think off! Tell me, what year is it? Where you are, I mean."

"What year? It's 1955, of course."

"Why," he said, "this is remarkable!"

"It is?"

"Do you know what I think has happened? A quantum inversion."

"Beg pardon?" I said.

"Karpo Sixteen predicted the possibility just the other day! Listen, my friend, let me ask you just a few questions—"

Then the mechanical voice of the operator cut in. It wasn't a real operator, of course, just a recorded voice, part of the new automatic system. These voices gave all the standard phrases and usually at the wrong time, the way the system was working. The worst of it was you couldn't argue with them or curse them—at least you always felt a little foolish afterward if you did.

The operator's voice said, "I'm sorry. Your time is up!"

"Now, wait!" said my communicant, his voice fading a little, "Don't cut us off! Don't think off yet!"

Again: "I'm sorry. Your time is up!"

And after that a click, and after that silence.

I jiggled the hook a few times. No result. I shrugged. I hung up and rearranged the papers on my desk and went back to work, forgetting for the moment the party I'd been trying to call in the first place. And forgetting the odd conversation I had just had. No—not quite. Not quite forgetting it. Queerly, it clung to my mind. What had he said his name was? Zon Twenty. Sounded like that, anyway. Odd name. Of course I still thought it was a gag of some kind. Yet it bothered me. Zon's manner, his tone of voice had been so convincing. What he had said suggested that in some queer way I had managed to place a telephone call into the future. But as a sane, normal, recently promoted colonel, I knew this was impossible.

At lunch I was still thinking about it. I ate in the officers' mess on my floor and steered my tray through the line. I saw, among other acquaintances Major "Clipper" Moskowitz at a far table, and remembered that he was a great science fan, always talking about rockets and reaching the moon, and that sort of thing—we had one argument about why a rocket works in a vacuum, such as space, and he hammered the table and drew diagrams and quoted Newton, and I'm still not convinced. Anyway, I went over and sat next to Clipper.

"'Lo, Larry. How's it?" he said.

"Routine," I said. "Latest request for overseas duty turned down. I'll probably die in the Pentagon with my pencil still behind my ear."

We talked of such things for several minutes.

"Clipper," I said finally, "you're the G.L.E. on this future science stuff—"

"The what?"

"Greatest Living Expert. Latest Pentagonese. Tell me, what do you think of the possibility of ever being in touch with the future?"

"You mean time travel?"

"I guess that's what you'd call it."

"Time travel is nonsense," he said. "A logical absurdity. By definition, time is a series of infinitesimally small moments in succession. Once a point in time is established, it can't be changed, any more than energy can be destroyed."

"I didn't say anything about changing anything. I was thinking about—well, talking with somebody in the future."

"Just as paradoxical," he said, shrugging, and taking a huge bite of braised beef tongue. "If you go into the future—or talk to the future—the future affects the change, through you. In other words, if you can't go back into the past, neither can people from the future. And it's inconceivable that such a thing wouldn't make changes. Maybe only small ones, but they'd multiply in time. 'Thou canst not change a flower, without troubling of a star.' That's Francis Thompson. You step on one spider today, and you affect the evolution of spiders, the ecology of all other things in the distant future. By a simple act like that you could destroy or create a whole species to come."

"My head swimmeth," I said. "All I want to know is—"

He wasn't even listening to me. He enjoyed spouting this kind of thing. "Of course, it's theoretically possible for you to witness events out of the past, without being party to them. If, for instance, you could travel away from Earth at more than the speed of light, overtaking the light waves of an event—say, the Monitor and Merrimac fight—"

"Or the Battle of Gettysburg," I said, loyal to the core.

"—you could look back and see it happen. The future? I doubt it. Unless in some way time and space actually curve back upon themselves, as some think."

"Uh huh," I said, and drank my coffee and finally left Clipper Moskowitz.

After that I did manage to forget about Zon Twenty temporarily. It was a busy week. The draft quota had gone up, and Personnel Planning had worked out new criteria for classification, and I had to study these to apply them to analysis. This won't make much sense to you unless you've worked in a military headquarters yourself. I worked. I had a dim idea that if I worked hard enough somebody would favorably regard one of my requests to get sent overseas.

I've got to explain something right here. I don't want anybody to get the idea I'm a hero type—a professional volunteer. But I'm a career officer, and overseas duty is the quickest way to tactical unit command, which is important on the record. The lack of it has kept many a perfectly good colonel from getting his first star and making that final big step.

So I worked hard, and of course, sent in another request for transfer, this time under the provisions of a different set of regulations. And I didn't think about Zon Twenty again until about a week later, one afternoon, when the phone rang.

"Personnel Analysis. Colonel Bog—"

He didn't even let me finish. "Well! I've found you again! The man from the past!"

"Oh, no," I said. "Don't tell me. Not Zon Twenty—"

"Yes, it's I, of course! Seems we've had another lucky accident, and been connected again. I was despairing of it for a while. Now, for machine's sake, don't go away this time! I've got to talk to you!"

"It's your dime," I said.

"Dime!" He pounced on it. "That was a monetary unit, when you had money, wasn't it?"

"Look, mister—"

"You haven't guessed what's happened, have you? We have it pretty well analyzed at this end. But we didn't really suppose your technology would be equal to it back there."

"Look, just who are you, and where are you?" I said.

"My name is Zon Twenty, as I told you. I'm an historical technician in the Office of Ancient Research in Washington, the capital of the planet, Earth. I'm an Earthman myself, of course. My job is to prepare studies of ancient civilizations such as yours—"

"Now, wait—what kind of a gag is this?"

"A gag? Oh—that's the ancient term for a joke. Good! I'll make a note of that!"

"Come on. Who is it? Did Clipper Moskowitz put you up to this?"

"Oh, dear," said Zon Twenty, and I could hear his heavy sigh. "I was afraid you wouldn't be able to grasp the situation. I'm going to have to offer proof, I suppose. Look here—exactly what date is it where you are?"

"I told you. 1955."

"I mean what month and year?"

"It's August 23, 1955—and I think you know that as well as I do."

"August 23. Just a minute ... we'll make a quick tape on the cyb, here. Ah, yes, here we are. August 23. All right. The nearest date of significance is September 1st. On the date twenty-one of your so-called nations reached—or should I say will reach—a new trade and tariff agreement in the U.N., and this will eventually lead directly to the free nation federation in—"

"I'm sorry! Your time is up!"

It was that blasted recorded voice of the mechanical operator again.

"Hey! Don't cut us off!" I said.

"Hello? Are you still with me? Look here—I'll try to call back! It's difficult, but I think I can!" said Zon Twenty.

"I'm sorry! Your time is up!"

And again the click, and silence.

This time I didn't forget Zon Twenty, neither quickly nor easily. If it was a gag, it was a beauty: crazy and elaborate, and the acting was superb. If it wasn't a gag—well, I couldn't yet quite believe that it wasn't a gag. A week streamed by in a sea of paperwork. My latest overseas transfer request came back disapproved. Then, on the morning of September 2nd I opened the newspaper and saw the headline:

TWENTY-ONE NATIONS REACH
TRADE ACCORD IN U.N.

I read the story. It was essentially what Zon had predicted—or remembered—or whatever you want to call it. I was confused now.

That day I didn't work very well. I couldn't concentrate. I am not a deep thinker, and have no illusions that I am. But one idea presented itself, starting as kind of hypnotic little glow in the bottom of my mind, and this grew until I could scarcely think about anything else.

Put it under the heading of temptation. Ask yourself if you would have been able to resist. Or just forget all the moral and ethical implications, and accept that I was tempted in this way. If I could be in touch with this Zon character—if he really was from the future, and an historical expert, at that—he could tell me all sorts of things that were going to happen. I could then either predict them or otherwise adjust my actions to fit them. I could go up so fast it would make Caesar's career look like a misfit reservist's. I could—

Well, then I started justifying and rationalizing. I could do my country all sorts of good. I thought along those lines for a while, and presently even managed to convince myself that my original purpose had been altruistic all along.

Of course I tried to get in touch with Zon Twenty again. Over and over again I dialed the number I had dialed the first time I had become connected with him by apparent accident. I dialed random numbers. I listened to a long and boring dissertation on permutation of numbers by Clipper Moskowitz in an effort to devise a system of hitting all possible combinations. There were an awful lot of possible combinations.

My phone rang again nearly ten days later.

It was Zon. He said, "Oh, there you are! I'd about given up! Look—the quantum inversion is swinging back to normal! This is the last time we'll be able to talk! So we've got to make every moment count!"

"Sure," I said. "You bet. Only I don't exactly get it. I don't understand just how all this happens. If you'd explain—"

"That's not important. Briefly, we use telepathic induction for message selection. That's why I was startled when you mentioned the ancient dial phone. And of course we don't have armies any more."

"Yes, but—"

"Listen, Colonel—what was your name? Never mind. You can be most valuable to me in my research. You can supply details about your time that simply don't exist any more—"

"Don't exist? Don't you have movies, recordings, magazines, all that stuff?"

"Of course not. They were all destroyed in the Final War."

"The what?"

"The Final War. You'll hear about it soon enough. If you survive, that is. Only three hundred thousand did, out of the entire population. They were the seed of our present civilization."

"Hey, now, wait a minute! What about this war? When was it? When's it going to be, I mean?"

"There's no point in your asking," said Zon. "You can't change it, you know. If you could change it, I wouldn't be here. My world as I know it wouldn't exist. The fact that my time does exist proves, therefore, you never changed it. Now, if you'll just calm down—"

"Calm down?" I shouted it across the centuries at him. "How can I? How would you feel? Look, this Final War, as you call it. Is it going to be soon? You can at least tell me that, can't you?"

"All right. Soon, as all time is reckoned. In your lifetime, I would say. Now, I suggest that you adjust yourself emotionally and accept what is inevitable. The best thing you can do is answer a few questions I've prepared."

I took his advice. I calmed down. "Questions? Well, Mr. Zon, or whatever your name is, I'll tell you what I'll do. I'll make a bargain with you. I'll answer your questions if you'll answer mine. I'll tell you what's happening here—anything you want to know—if you look in that little file of yours and tell me what's going to happen in my time. A deal?"

He was silent for a moment, and at first I thought we'd been cut off again.

"Hello? Zon? You still there?"

"Yes, I'm still here." His voice had become oddly quiet. "So it's the old Faust legend all over again, is that it?"

"I don't know what you're talking about," I said. I didn't—then. "You just answer my questions, and I'll answer yours. Mine first."

"All right," he said. "Very well."

And I started my barrage. When would the Final War start? He told me. How would it start? He told me that. Who would be the belligerents, and what weapons and techniques would be used at first, and what new ones would be developed? He knew. Where would the major campaigns be fought—how many troops would be involved? I got the whole story. I scribbled furiously and put it on paper.

Afterwards, he asked his questions. They were innocuous, compared to mine. He wanted to know about taboos and marriage customs and slang expressions and education and eating habits and articles of clothing. I told him.

I was in the midst of an explanation of the game of Bingo, of all things, when there was a sudden whooshing and crackling in the earpiece of the telephone.

"Hello? Zon? Still with me?"

"Yes—but I think the signal's going out. This may be the inversion passing! We probably won't be able to talk again. Hello? Do you still hear?"

"I do. Look—one more thing before we go. You said this dictator—the one everybody hated so much—survived the final series of blasts. He and his staff. Where were they? Where were they when the blasts came?"

"In a country at that time called Canada. Little place named Resolution, on Great Slave Lake. They'd dug in there—very elaborate underground installation."

"And the date you gave me is correct?"

"As far as I know. You're determined to be in that place at that time, I suppose." He seemed amused.

"You can say that again," I said.

There were more rumblings of static on the line.

"Well, since you're so determined," said Zon Twenty, "one more word of advice. The dictator and all his followers were afterwards imprisoned by what populace remained. Small wonder, since they were mainly responsible for all the carnage. It was a pretty horrible thing. They were slowly and most savagely tortured continuously for nearly two decades. So if you mean to be there, at Great Slave Lake, I suggest you arrange to be on the right side."

"Don't worry," I said. "I'll arrange it somehow. Larry Boggs is going to live through this, if anybody is—"

"What's that? What's that you said?"

"I said I'm going to live through this—"

"No, no, the name. Boggs. Is that your name?"

"Certainly that's my name. Colonel Lawrence E. Boggs, United States Army, and—"

He was laughing. He was laughing loudly, uproariously, and, I thought, hollowly.

The background noise in the receiver had been steadily getting worse. Now it swelled, like an angry sea. Interference of some sort snarled and crackled. A sick feeling began to grow like fungus in my stomach.

Suddenly his voice came through again. He was still laughing. "Generalissimo Lawrence E. Boggs survived all right Colonel, he—"

All the noise cut away suddenly. There was a pinpoint of silence.

Then the mechanical operator:

"I'm sorry! Your time is up!"