Quimby pointed to the model on his desk. "You use this. You see how it works? Just like a typewriter. Don't you try to write or print anything by hand. Just use the machine. Now you take booth 5-B, and if you need help, just press the red button and someone will come. Down that aisle, son, on the right."

He watched the youngster go down the aisle and out of view and smiled. No one was ever turned away from Multivac. Of course, there was always a certain percentage of trivia: people who asked personal questions about their neighbors or obscene questions about prominent personalities; college youths trying to outguess their professors or thinking it clever to stump Multivac by asking it Russell's class-of-all-classes paradox and so on.

Multivac could take care of all that. It needed no help.

Besides, each question and answer was filed and formed but another item in the fact assembly for each individual. Even the most trivial question and the most impertinent, insofar as it reflected the personality of the questioner, helped humanity by helping Multivac know about humanity.

Quimby turned his attention to the next person in line, a middle-aged woman, gaunt and angular, with the look of trouble in her eye.

Ali Othman strode the length of his office, his heels thumping desperately on the carpet. "The probability still goes up. It's 22.4 per cent now. Damnation! We have Joseph Manners under actual arrest and it still goes up." He was perspiring freely.

Leemy turned away from the telephone. "No confession yet. He's under Psychic Probing and there is no sign of crime. He may be telling the truth."

Othman said, "Is Multivac crazy then?'

Another phone sprang to life. Othman closed connections quickly, glad of the interruption. A Corrections officer's face came to life in the screen. The officer said, "Sir, are there any new directions as to Manners' family? Are they to be allowed to come and go as they have been?"

"What do you mean, as they have been?'"

"The original instructions were for the house arrest of Joseph Manners. Nothing was said of the rest of the family, sir."

"Well, extend it to the rest of the family until you are informed otherwise."

"Sir, that is the point. The mother and older son are demanding information about the younger son. The younger son is gone and they claim he is in custody and wish to go to headquarters to inquire about it."

Othman frowned and said in almost a whisper, "Younger son? How young?"

"Sixteen, sir," said the officer.

"Sixteen and he's gone. Don't you know where?"

"He was allowed to leave, sir. There were no orders to hold him."

"Hold the line. Don't move." Othman put the line into suspension, then clutched at his coal-black hair with both lands and shrieked, "Fool! Fool! Fool!"

Leemy was startled. "What the hell?"

"The man has a sixteen-year-old son," choked out Othman. "A sixteen-year-old is not an adult and he is not filed independently in Multivac, but only as part of his father's file." He glared at Leemy. "Doesn't everyone know that until eighteen a youngster does not file his own reports with Multivac but that his father does it for him? Don't I know it? Don't you?"

"You mean Multivac didn't mean Joe Manners?" said Leemy.

"Multivac meant his minor son, and the youngster is gone, now. With officers three deep around the house, he calmly walks out and goes on you know what errand."

He whirled to the telephone circuit to which the Corrections officer still clung, the minute break having given Othman just time enough to collect himself and to assume a cool and self-possessed mien. (It would never have done to throw a fit before the eyes of the officer, however much good it did in purging his spleen.)

He said, "Officer, locate the younger son who has disappeared. Take every man you have, if necessary. Take every man available in the district, if necessary. I shall give the appropriate orders. You must find that boy at all costs."

"Yes, sir."

Connection was broken. Othman said, "Have another rundown on the probabilities, Leemy."

Five minutes later, Leemy said, "It's down to 19.6 per cent. It's down."

Othman drew a long breath. "We're on the right track at last."

Ben Manners sat in Booth 5-B and punched out slowly, "My name is Benjamin Manners, number MB-71833412. My father, Joseph Manners, has been arrested but we don't know what crime he is planning. Is there any way we can help him?"

He sat and waited. He might be only sixteen but he was old enough to know that somewhere those words were being whirled into the most complex structure ever conceived by man; that a trillion facts would blend and co-ordinate into a whole, and that from that whole, Multivac would abstract the best help.

The machine clicked and a card emerged. It had an answer on it, a long answer. It began, "Take the expressway to Washington, D.C. at once. Get off at the Connecticut Avenue stop. You will find a special exit, labeled 'Multivac' with a guard. Inform the guard you are special courier for Dr. Trumbull and he will let you enter.

"You will be In a corridor. Proceed along it till you reach a small door labeled 'Interior.' Enter and say to the men inside, 'Message for Doctor Trumbull.' You will be allowed to pass. Proceed on-"

It went on in this fashion. Ben could not see the application to his question, but he had complete faith in Multivac. He left at a run, heading for the expressway to Washington.

The Corrections officers traced Ben Manners to the Baltimore station an hour after he had left. A shocked Harold Quimby found himself flabbergasted at the number and importance of the men who had focused on him in the search for a sixteen-year-old.

"Yes, a boy," he said, "but I don't know where he went to after he was through here. I had no way of knowing that anyone was looking for him. We accept all comers here. Yes, I can get the record of the question and answer."

They looked at the record and televised it to Central Headquarters at once.

Othman read it through, turned up his eyes, and collapsed. They brought him to almost at once. He said to Leemy weakly, "Have them catch that boy. And have a copy of Multivac's answer made out for me. There's no way any more, no way out. I must see Gulliman now."

Bernard Gulliman had never seen Ali Othman as much as perturbed before, and watching the coordinator's wild eyes now sent a trickle of ice water down his spine.

He stammered, "What do you mean, Othman? What do you mean worse than murder?"

"Much worse than just murder."

Gulliman was quite pale. "Do you mean assassination of a high government official?" (It did cross his mind that he himself-).

Othman nodded. "Not just a government official. The government official."

"The Secretary-General?" Gulliman said in an appalled whisper.

"More than that, even. Much more. We deal with a plan to assassinate Multivac!"

"WHAT!"

"For the first time in the history of Multivac, the computer came up with the report that it itself was in danger."

"Why was I not at once informed?"

Othman half-truthed out of it. "The matter was so unprecedented, sir, that we explored the situation first before daring to put it on official record."

"But Multivac has been saved, of course? It's been saved?"

"The probabilities of harm have declined to under 4 per cent. I am waiting for the report now."

"Message for Dr. Trumbull," said Ben Manners to the man on the high stool, working carefully on what looked like the controls of a stratojet cruiser, enormously magnified.

"Sure, Jim," said the man. "Go ahead."

Ben looked at his instructions and hurried on. Eventually, he would find a tiny control lever which he was to shift to a DOWN position at a moment when a certain indicator spot would light up red.

He heard an agitated voice behind him, then another, and suddenly, two men had him by his elbows. His feet were lifted off the floor.

One man said, "Come with us, boy."

All Othman's face did not noticeably lighten at the news, even though Gulliman said with great relief, "If we have the boy, then Multivac is safe."

"For the moment."

Gulliman put a trembling hand to his forehead. "What a half hour I've had. Can you imagine what the destruction of Multivac for even a short time would mean. The government would have collapsed; the economy broken down. It would have meant devastation worse-" His head snapped up, "What do you mean for the moment?"

"The boy, this Ben Manners, had no intention of doing harm. He and his family must be released and compensation for false imprisonment given them. He was only following Multivac's instructions in order to help his father and it's done that. His father is free now."

"Do you mean Multivac ordered the boy to pull a lever under circumstances that would burn out enough circuits to require a month's repair work? You mean Multivac would suggest its own destruction for the comfort of one man?"

"It's worse than that, sir. Multivac not only gave those instructions but selected the Manners family in the first place because Ben Manners looked exactly like one of Dr. Trumbull's pages so that he could get into Multivac without being stopped."

"What do you mean the family was selected?"

"Well, the boy would have never gone to ask the question if his father had not been arrested. His father would never have been arrested if Multivac had not blamed him for planning the destruction of Multivac. Multivac's own action started the chain of events that almost led to Multivac's destruction."

"But there's no sense to that," Gulliman said in a pleading voice. He felt small and helpless and he was virtually on his knees, begging this Othman, this man who had spent nearly a lifetime with Multivac, to reassure him.

Othman did not do so. He said, "This is Multivac's first attempt along this line as far as I know. In some ways, it planned well. It chose the right family. It carefully did not distinguish between father and son to send us off the track. It was still an amateur at the game, though. It could not overcome its own instructions that led it to report the probability of its own destruction as increasing with every step we took down the wrong road. It could not avoid recording the answer it gave the youngster. With further practice, it will probably learn deceit. It will learn to hide certain facts, fail to record certain others. From now on, every instruction it gives may have the seeds in it of its own destruction. We will never know. And however careful we are, eventually Multivac will succeed. I think, Mr. Gulliman, you will be the last Chairman of this organization."