"Something's up," Ground Control said. "It's coming in too slowly."

"I see that," he answered. "It must be covering something beyond it, in your radar shadow."

It was. When he was almost free of the last traces of atmosphere he saw the other cruiser, far out and hidden from Ground Control's radar by the radar shadow cast by the first one.

He reported, giving its position and course as given him by the robot astrogating unit.

"We'll have the greatest amount of time if I make turn-over now and decelerate," he finished.

The voice of Harding came through the auxiliary speaker: "Do so."

The Argosy swung, end for end, and he decelerated. The cruiser behind him increased its speed, making certain it would be in position to cut off any return to Earth. The other cruiser altered its course to intersect the point in s.p.a.ce the Argosy would soon occupy, and the Argosy was between the rapidly closing jaws of a trap.

He made reports to Ground Control at one-minute intervals. At 11:49 he said: "Our velocity is approaching zero. We'll be within range of the second cruiser's blasters in two more minutes."

Harding spoke again to him: "We'll go into the warp now. Do not alter the deceleration or the course of the ship while we're in the warp."

"I won't," he said.

There was a faint mutter from the auxiliary speaker as Harding gave some instructions to Garvin. Engle took a last look at the viewscreen; at blue-green Earth looming large in the center, Orion and Sirius glittering above it and the sun burning bright and yellow on the right. It was a scene he had observed many times before, all very familiar and normal- The chronometer touched 11:50 and normalcy vanished.

Earth and sun and stars fled away from him, altering in appearance as they went, shrinking, dwindling. The seas and continents of Earth erupted and shook and boiled before Earth faded and disappeared. The sun changed from yellow to green to blue, to a tiny point of bright violet light that raced away into the blackness filling the screen and faded and disappeared as Earth had done.

Then the viewscreen was black, utterly, completely, dead black. And the communicator that had connected him with Ground Control was silent, without the faintest whisper of background sound or s.p.a.ce static.

In the silence the voice of Harding as he spoke to Garvin came through the speaker; puzzled, incredulous, almost shocked: "Our velocity couldn't have been that great-and the sun receded into the ultraviolet!"

There was the quick sound of hurrying footsteps then the more distant sound of the computer's keys being operated at a high rate of speed. He wanted to ask what had gone wrong but he knew no one would answer him. And it would be a pointless question-it was obvious from Harding's tone that he did not know, either.

He had an unpleasant feeling that Man's first venture into another dimension had produced catastrophic results. What had caused sun and Earth to disappear so quickly- and what force had riven and disfigured Earth?

Then he realized the significance of Harding's statement about the sun receding into the ultraviolet.

If the ship had been traveling at a high velocity away from the sun, the wave length of the sun's light would have been increased in proportion to the speed of the ship. The sun should have disappeared in the long-wave infrared end of the spectrum, not the short- wave ultraviolet.

With the thought came the explanation of the way the continents and oceans of Earth had quivered and seethed. The shifting of the spectrum range had shortened normally visible rays into invisibly short ultraviolet radiations while at the same time formerly invisible long infrared radiations had been shortened into visible wave lengths. There had been a continuous displacement into and past the ultraviolet and each wave length would have reflected best from a different place-mountains, valleys, oceans, deserts, warm areas, cool areas-and the steady progression into the ultraviolet had revealed each area in quick succession and given the appearance of agitated movement.

So there was no catastrophe and everything had a logical explanation. Except how they could have been approaching a sun that he had seen clearly, visibly, racing away from them.

"Engle-" The voice of Harding came through the speaker. "We're going back into normal s.p.a.ce to make another observation. I don't know just where we are but we're certain to be far from the cruisers. Don't alter our course or velocity."

"Yes, sir," he said.

They came out of the warp at 11:53. The communicator burped suddenly and the viewscreen came to life; a deep, dull red that brightened quickly. A tiny coal flared up, swelling in size and shifting from red to orange to yellow-the sun. Earth appeared as a hazy red dot that enlarged and resolved itself into a planet with distorted continents that trembled and changed, to resume their natural shapes and colors. Within a few seconds the sun was shining as ever, Earth loomed large and blue-green before them and the stars of Orion glittered unchanged beyond. Even their position in s.p.a.ce was the same-they had not moved.

But the Slug cruisers had.

One was very near and from its forward port came the violet haze that always preceded a blaster beam. There was no time to escape-no chance at all. He spoke into the mike, harsh and urgent: "Into the warp! There's a blaster beam coming-move!"

There was a silence from below that seemed to last an eternity, then the sound of a switch being slapped hastily. At the same time, the violet haze before the cruiser erupted into blue fire and the blaster beam lanced out at them.

It struck somewhere astern. The power output needle swung jerkily as the generators went out and the emergency batteries took the heavy load of the shuttle's operation. There was a sensation of falling as the ship's artificial gravity units ceased functioning. The auxiliary speaker rattled wordlessly and there was a sound like a hard rush of wind through it, accompanied by quick b.u.mping sounds.

Then the speaker was still and there was no sound of any kind as the viewscreen shifted into the ultraviolet and Earth and stars and sun once again raced away and disappeared in the blackness.

A myriad of lights above the board informed him the generators were destroyed, the stern section riddled and airless, the emergency batteries damaged and reduced to quarter charge, the shuttle room punctured and airless.

And, of course, Harding and Garvin were dead.

He felt a surge of futile anger. It had all been unnecessary. If only they had not considered him incompetent to be entrusted with anything more than the ship's operation-if only they had installed an emergency switch for the shuttle by his control board, there would not have been the two-second delay following his order and they would have been safely in the warp before the blaster beam struck.

But they had not trusted him with responsibility and now he was alone in a s.p.a.ce warp he did not understand; sole and full responsibility for the shuttle suddenly in his hands.

He considered his course of action, then got into a pressure suit. Magnets in the soles of its heavy boots permitted him to walk in the absence of gravity and he went to the interroom airlock and walked down what had been the room's wall, then across to the center of its floor.

But for the fact there was no one in the room, it was as he had last seen it. The shuttle, computer, and other equipment stood in their orderly positions with their lighted dials unchanged. Until one looked at the gash ripped in the hull and saw the stains along its edge where the occupants had been hurled through it by the escaping air.

He went on to the next room and the next. The damage increased as he proceeded toward the stern. The power generators were sliced into ribbons and the emergency batteries in such condition it seemed a miracle they were functioning at all. The drives had received the greatest damage; they were an unrecognizable ma.s.s of wreckage.

He made his way back to the shuttle room, there to appraise his circ.u.mstances. First, he would have to make the shuttle room livable; get out of the pressure suit. He would have to question the computer and he could not do that with the thick, clumsy gloves on his hands.

The job didn't take long. There were repair plates on the ship and a quick-hardening plastic spray. He closed the sternward airlock when he was done and opened the airlock leading to the control room, as well as the locks beyond. Air filled the shuttle room, with only a minor overall loss of air pressure. He removed the suit, attached a pair of magnetic soles to his shoes so he could operate the keys of the computer without the movements sending him floating away, and went to it.

He had never been permitted to touch it before, nor even stand close enough to see what the keyboard looked like. Now, he saw that the alphabetical portion of the keyboard was minor compared with the mathematical portion, many of the symbols strange to him.

The operation of an interplanetary ship required a certain knowledge of mathematics, but not the kind used by theoretical physicists. He typed, doubtfully: ARE YOU CAPABLE OF ANSWERING QUESTIONS PRESENTED IN NON-.

MATHEMATICAL FORM?.

The word, YES, appeared at once in the answer panel and relief came to him like the lifting of a heavy burden.

The computer knew as much about the s.p.a.ce warp as Harding or anyone else. It was connected with his drive controls and instruments and knew how far, how fast, and in what directions the flight had taken place. It had even been given blueprints of the ship's construction, in case the structure of the ship should affect the ship's performance in the warp, and knew every nut, bolt, plate and dimension in the ship.

There was supposed to be a certain method of procedure when questioning the computer. "It knows-but it can't think," Garvin had once said. "It lacks the initiative to correlate data and arrive at conclusions unless the procedure of correlation is given it in detail."

Perhaps he could manage to outline some method of correlation for the computer. The facts of his predicament were simple enough: He was in an unknown medium called "the s.p.a.ce Warp." Something not antic.i.p.ated occurred when a ship went into the warp and Harding had not yet solved the mystery when he died. The physicists in Observation would be able to find an answer but he could not ask them. The forward movement of the ship was not transferred with it into the warp and if he emerged into normal s.p.a.ce the waiting Slug cruisers would disintegrate him before he spoke three words to Observation.

There was a pencil and a tablet of paper by the computer. He used them to calculate the time at which the charge in the damaged batteries would reach a critical low, beyond which the charge would be insufficient to activate the shuttle.

The answer was 13:53. He would have to go out of the warp at 13:53 or remain in it forever. He had a great deal less than two hours in which to act.

He typed the first question to the computer: WHAT IS THE POSITION OF THIS SHIP RELATIVE TO NORMAL s.p.a.cE?.

The answer appeared on the panel at once; the coordinates of a position more than a light-year toward Ophiuchus.

He stared at the answer, feeling it must be an error. But it could not be an error-the computer did not make mistakes. How, then, could the ship have traveled more than a light-year during its second stay in the warp when it had not moved at all during the first stay? Had some factor of the warp unknown to him entered the picture?

As a check he typed another question: WHAT WAS OUR POSITION, RELATIVE TO NORMAL s.p.a.cE,.

IMMEDIATELY BEFORE THIS SHIP WAS SHUTTLED BACK OUT OF THE.

WARP?.

The answer was a position light-days toward Ophiuchus.

He typed: IMPOSSIBLE.

The computer replied: THIS STATEMENT CONFLICTS WITH PREVIOUS DATA.

He recalled the importance of keeping the computer free of all faulty or obscure data and typed quickly: CANCEL CONFLICTING STATEMENT.

CONFLICTING STATEMENT CANCELED, it replied.

He tried another tack. THIS SHIP EMERGED FROM THE s.p.a.cE WARP INTO THE SAME NORMAL s.p.a.cE POSITION IT HAD OCCUPIED BEFORE GOING.

INTO THE WARP.

He thought the computer would proceed to give him some sort of an explanation.

Instead, it noncommittally replied: DATA ACKNOWLEDGED.

He typed: EXPLAIN THIS DISCREPANCY BETWEEN s.p.a.cE WARP AND NORMAL s.p.a.cE POSITIONS.

It answered: INSUFFICIENT DATA TO ACCOUNT FOR DISCREPANCY.

He asked: HOW DID YOU DETERMINE OUR PRESENT POSITION?

It replied: BY TRIANGULATION, BASED ON THE RECESSION OF EARTH, THE SUN, SIRIUS, ORION, AND OTHER STARS.

BUT THE RECEDING SUN WENT INTO THE ULTRAVIOLET, he objected.

Again it answered with the noncommittal, DATA ACKNOWLEDGED.

DID YOU ALREADY HAVE THIS DATA? he asked.

YES.

EXPLAIN WHY THE RECEDING SUN SHIFTED INTO THE ULTRAVIOLET.

INSTEAD OF THE INFRARED.

It replied: DATA INSUFFICIENT TO ARRIVE AT LOGICAL EXPLANATION.

He paused, pondering his next move. Time was speeding by and he was learning nothing of value. He would have to move the ship to some place in the warp where emergence into normal s.p.a.ce would not put him under the blasters of the Slug cruisers.

He could not know where to move the ship until he knew where the ship was at the present. He did not believe it was in the position given him by the computer, and its original s.p.a.ce warp position had certainly not been the one given by the computer.

The computer did not have the ability to use its knowledge to explain contradictory data. It had been ordered to compute their s.p.a.ce warp position by triangulation of the receding sun and stars and was not at all disturbed by the contradicting shift of the sun into the ultraviolet. Suppose it had been ordered to calculate their position by computations based on the shift of the sun's and stars' spectrum into the ultraviolet?

He asked it: WHAT IS OUR POSITION, IGNORING THE TRIANGULATION AND BASING YOUR COMPUTATIONS ON THE SHIFT OF THE SPECTRUMS OF.

THE SUN AND ORION INTO THE ULTRAVIOLET?.

It gave him the coordinates of a position almost two light-years toward Orion. The triangulation computations had shown the ship to be going backward at many times the speed of light; the spectrum-shift computations showed it to be going forward with approximately the same speed.

THIS SHIP CANNOT SIMULTANEOUSLY BE IN TWO POSITIONS THREE.

LIGHT-YEARS APART. NEITHER CAN IT SIMULTANEOUSLY BE GOING.

FORWARD AND BACKWARD.

DATA ACKNOWLEDGED, it agreed.

USE THAT DATA TO EXPLAIN THE CONTRADICTIONS OF THE TWO.

POSITIONS YOU COMPUTED.

DATA INSUFFICIENT TO ARRIVE AT LOGICAL EXPLANATION, it answered.

ARE YOU CERTAIN THERE WAS NO ERROR IN YOUR CALCULATIONS?.

THERE WAS NO ERROR.

DO YOU KNOW THAT IF WE DROPPED BACK INTO NORMAL s.p.a.cE, IT.

WOULD BE AT NEITHER OF THE POSITIONS YOU GAVE ME?.

It replied with the characteristic single-mindedness: DATA SHOWS OUR TWO POSITIONS TO BE THOSE GIVEN.

He paused again. He was still getting nowhere while time fled by. How swiftly less than a hundred minutes could pa.s.s when they were all a man had left to him . . .

The computer was a genius with the mental initiative of a moronic child. It could find the answer for him but first he would have to take it by the hand and lead it in the right direction. To do that he would have to know more about the warp.

He wrote: EXPLAIN THE NATURE OF THE s.p.a.cE WARP AS SIMPLY AS POSSIBLE AND WITHOUT USING MATHEMATICS HIGHER THAN ALGEBRA.

It answered at once: THIS CANNOT BE DONE.

The chronometer read 12:30. He typed: THIS SHIP WILL HAVE TO RETURN TO NORMAL s.p.a.cE NO LATER THAN.

13:53. IT MUST BE MOVED TO A DIFFERENT POSITION WHILE STILL IN THE.

WARP.

DATA ACKNOWLEDGED, it replied.

THIS SHIP CANNOT OCCUPY TWO POSITIONS AT THE SAME TIME. YOUR.