"I'm pointing for Alpha Centauri," said Paul. "And so that's what we calculate for."

Nora looked at the bays of neat equipment and shook her head. "Why not aim at it and run?" she asked. "Surely you do not need this billion dollars' worth of stuff to point out your destination."

"We do," objected Paul. "You see, if I took off with my telescope pointed along the axis of drive with the cross-hairs pointing at Alpha Centauri, I'd be heading for the star where it was four years ago. I intend to be on the way for nine days. So I'll want to point the nose of the ship at the spot where Alpha will be nine days in the future instead of four years in the past. Since Sol and Alpha drift in space, the motion and velocities of both systems must be taken into account, a correction-angle found, and then used to aim my ship. My telescope will angle away from the ship's axis by that correction-angle. Add to that the fact that I am taking off from earth, which will give me some angular velocity and some rotational velocity differing from an hypothetical take-off from Sol itself. Furthermore, I want Proxima Centauri instead of Alpha, and that must be taken into consideration too.

"Then there is the question of velocity and time. We cannot see when we are exceeding the velocity of light. We must run at so many light-velocities for so many seconds. A minor error in timing or velocity will create a rather gross error in position at the end of the run."

"Oh," said Nora, but her tone indicated a lack of comprehension.

Paul smiled. "One second of error at one light-velocity equals a hundred and eighty-six thousand miles of error. One second of error at a hundred times the velocity of light equals eighteen millions of miles error. Not much as cosmic distance goes, but a long way to walk."

Nora understood that, and said so.

Grayson's data had been handed to him by Haedaecker. But apparently the long-range calculations that had been temporarily halted were still halted, for the operator was taking this opportunity of feeding some future flight-constant information to the big machine.

It was not a complex calculation as some computations may go, but there were a myriad of factors. Terran latitude and longitude, the instant of take-off as applied to the day and the year, an averaging of previous dispersion-factors noted from previous trips, velocities, vector angles, momentum, and others, all obtained from tables and entered in the machine before the start lever was pulled. The machine mulled the information over, tossed electrons back and forth, chewed and digested a ream of binary digits, and handed forth a strip of paper printed with an entire set of coordinates in decimal angles.

Paul showed Nora his folder of data. "The rest," he said, "is up to me."

He led Nora from the computation room, intending to hit the dining room for coffee. Half-way across the lobby of the administration building he was hailed by the autocall. He went to the telephone.

It was Stacey.

"I've a couple of things to let you think over," said Stacey.

"So?"

"I've been on the job. I haven't much, but there are a few items you might mull over."

"Shoot."

"One. Your deceased thief was an ex-convict, escaped from the penal colony on Antarctica."

"This I've heard."

"Then I suppose you know that the guy was cashiered from the Neoterra run for smuggling."

"Huh?" blurted Paul.

"An ex-pilot, tossed out on his right ear for conduct hardly becoming a safecracker and a thief, let alone an officer and a gentleman."

"That I didn't know. How long ago?"

"Five years, almost."

It was not quite the ten that Nora had claimed.

"Well, that makes it—"

"That ain't all," came Stacey's voice. "The weapons carried by the Spaceport guards are regulation Police Positives. Our erstwhile felon was shot once, right between the eyes, with a forty-five, which according to all of the expert opinion, came from an automatic at a distance of three feet, plus or minus six inches. Know what that means?"

"I'm just digesting the information now. You tell me."

"It means that the ex-crook was killed by a party or parties unknown, someone other than one of the guards. Furthermore, he was facing his executioner, not taking it on the lam. How do you make that?"

"It doesn't make good sense."

"Sure it does. It keystones nicely. Men of that calibre are often chilled because they fumble a job and the mainspring doesn't enjoy the prospect of having a fumbler running around with information that might lead to the capture, arrest, conviction, and/or demise of aforementioned mainspring. They made one error. They should have used a thirty-eight revolver instead of a forty-five automatic. The forty-five is a gangster's weapon. And they should have drilled their ex-companion from behind between the scapulae to make it look as though the guards were better shots than they really are."

"That's food for thought," said Paul.

"That isn't all," said Stacey. "Here's one more bit of information that may be either juicy or full of sawdust depending upon how you taste it. Your girl friend, Nora Phillips was born and raised on Neoterra."

"You're certain of that?"

"So the Bureau of Vital Statistics claims."

"But how—?"

"Negative evidence, my fine scientist. Negative evidence. I offer you two alternatives. Either she was born on Neoterra, or she is employing an alias, pseudonym, or nom de jour." Stacey's French lacked a certain vocabulary, but it was none the less to the point. "She is certainly not born Nora Phillips of Terra. I'll let you pick your choice. But enough of that. A couple of hours ago she received a telephone call. Nice position she must have. She chinned for about three minutes and then leaped to her feet and took off like jet propelled. Didn't bother to say anything to the management of the joint at all. Then—"

"Where does she work?" asked Paul.

"Timothy, McBride, and Webster, Attorneys-at-Law. We couldn't tap their telephone, but we had a lip-reader peering at her through a telescope from a room in the building opposite hers."

"What did he catch?"

"Nothing, she just listened, and then took off. And can that dame drive! If we didn't have an idea of where she was going after the first few minutes, my man would have lost her for certain. She with you now?"

"Uh-huh."

Paul thought fast. Just what unearthly reason why people would try to stop his plans for creating voice-fast communications with Neosol, Paul could not fathom. Obviously there was one faction working against him. But how had they—

Paul paled.

Had the criminal hoped to lay Paul low enough to keep him quiet until the criminal could take off in Paul's place? True identification would be impossible once the crook were in space. But what could he accomplish? Certainly—

Suppose the thief that clipped him intended to place Paul in a position where he could be captured easily. To take Paul's place to perform certain acts in Paul's name, while Paul was held captive. Then, once these acts were consummated Paul could be found in the wreck of a spacecraft or the ruin of a radio beacon on Proxima Centauri I.

But why? Columbus had been kicked around for having screwy ideas, and the Brothers Wright had been thoroughly laughed-at. But people did not try to murder characters who had cockeyed ideas. Of course, there was Galileo, but Galileo had publicized his screwy ideas, whereas Paul Grayson's theories were known to very few.

But Nora Phillips could not be held as part of that particular mob. It seemed to Paul that the woman had done a fine job towards keeping Paul hale, hearty, healthy, and imbued with ideas available only to a man in the finest of health of mind and body. If Nora belonged to some group intent on stopping Paul Grayson, she was working against them, too. For she had done a fine job of smoothing the headache out of his skull with fingers that acted with experience and practise.

On the other hand, Nora Phillips had behaved as though she wanted Paul to succeed, and she acted—if this were an act—as though she enjoyed her work.

So what had really happened last night when Paul Grayson was clipped unconscious?

Had Nora forestalled them—them?

Nora was quite a woman. Her loveliness was not of the untouchable, fragile, bandbox variety; perfection that must not be marred by a misplaced hair or a wrinkle in the frock—or a clue of rouge, printed offset from her own ripe lips to her own smooth cheek by Paul. Nora was all-desirable woman, and neither complete dishabille nor minor imperfection would mar her appeal. Paul recalled the lithe slenderness of her body. Her sculptured arms were molded with the smooth, well balanced muscle of fine tonus. Her waist was slender but not too soft—

"Hey! Are you there?"

"Yeah, Stacey. I was thinking."

"Don't think so hard."

"Look, Stacey. Can you tell me whether the man who clipped me turned up with scratches on his face?"

"I don't know. Why?"

"Just a loose end."

"I might be able to find out."

"Take a swing at it; but it's not too important."

"Okay, Paul. Have I given you something to think about?"

"More than," said Paul soberly. He hung up, turned, and saw the guard of the previous evening standing near by, about to go on duty. Paul went over and asked: "Hi!"

"Hello. Say, I'm sorry about last night—"

"Forget it, you were doing your duty. But can you tell me: Did the guy who used my identification last night have any scratches on his face?"

The guard frowned in thought. "All he had was some well-applied make-up, and a fine job it was, too. He looked me right in the eye."

"No marks?"

"Not a trace."

Paul smiled and went back to Nora, thinking furiously. Something must have interfered with their little plan. He looked at Nora, lissome, lovely, as lithe as a tiger. All desirable—

But maybe it might be a good idea for him to learn her desires, to ascertain her limit before he took any liberties with her beautiful white body. Intelligent women did not scream or faint these days, nor did they rake their attacker with fingernails. They employed Judo.

Now, if Nora Phillips knew Judo, it was plausible that the erstwhile footpad instead of finding an inert victim and an hysterical woman, discovered that the woman was capable of defending her outraged dignity, revenging their cowardly attack, and thwarting any further plans the criminal held for them both. It would explain in part why the criminal's little idea did not culminate as expected.

If Nora Phillips knew Judo.

Paul smiled faintly. He had not changed his mind about Nora Phillips; she was still the type of woman that would react unfavorably to any crude attempt at approach.

Regardless of whether her interest in him were an act, swift passion, or the awakening of tender love, Paul knew that she would not employ the punishing Judo holds upon him, if she knew Judo. On the other hand, Paul believed that instinct might react faster than intellect, and that her first instinctive move would give her away.

So Paul took her hand as he came close to her. He drew her forward, his free arm gliding towards her waist and around it.

Nora's free hand moved forward, upward, touched his cheek, and then went on around his neck. The hand that he held came free and joined the other. She was warm and supple in his arms and her lips were soft and clinging.

It was a satisfying emotional experience. Intellectually it proved nothing that had not been empirical knowledge for a couple of millions of years.

Paul would never learn whether Nora knew Judo by that method. He abandoned his primary intrigue for the moment and indulged in one of his favorite indoor sports.

Then she moved back a bit, and Paul's hands slipped to either side of her waist. "I could learn to like this sort of thing," he said.

Nora looked up into his eyes. Her own eyes were a trifle dreamy, but a trace of smile lurked in the deep corners of her mouth. "But how do I know you'll be true to me?" she asked him in a voice that sounded like pure soap opera. "In space—"

"I've a dame in every port," he told her. "I'm true to 'em all."

"But why so many?" chuckled Nora.

"Variety." Paul let go of Nora's waist and she stepped back a bit. He turned around and started leading her the rest of the way towards the coffee shop. "I've a couple of hours left," he said. "I'd prefer to soak up some dinner in candlelight, with music, et al. But Ptomaine Joe's is handy. I've hit so many snags so far that I'm inclined to find me an advantage and then sit on it until I'm safe in space."

Nora shuddered a bit. "Safe in space," she said softly. "That's a strange thing to say."

"Why?" he asked.

"So far out there, away from the friendly earth; nothing solid to stand upon, nothing to—"

Paul laughed. "No footpads to raise lumps on the skull, no taxicabs to dodge, no—"

"No women to kiss?"

"You've convinced me! But I'm baffled by you. What kind of job do you hold?"

"Why?"

"It isn't everybody that can pick up and leave their work for an idle afternoon."

"Oh," and her laugh was genuine. "I'm librarian for a large office of lawyers. I can get away because of polite confusion. No matter who misses me, he assumes that I am looking up a batch of stuff for one of the others. There are so many of them that they couldn't possibly get their heads together close enough to check up. Actually I'm doing just that often enough so that I can play hookey once in a while and not get caught."

Paul laughed with Nora. He felt at ease with her and her presence made him forget all of the niggling little questions that bothered him. Time passed swiftly enough to surprise them both when the announcer called the time and number of Paul's spaceflight.

"This is it," he said ruefully.

"So it is," she agreed. "There's another day."

"I'll call for it when I get back."

"Do that," she said. It was not a tone of command. It was more a tone of absolute agreement. It pleased him.

"Raging Vegan Gorgons couldn't stop me," he chuckled. He reached for her and she went into his arms forward for a good-bye kiss. Paul made the most of it; gave it all he knew how to give, and for his efforts he received a pleasant promise for the future in return.

Nora leaned back in his arms, took his hands from around her waist, and turned him to face the spaceport door.

"It's that way," she said in a throaty voice. She gave him a gentle shove. He went through the door and out upon the spacefield, walking across the sandy floor towards the spacecraft numbered BurAst P.G.1.

Actually, the spacecraft was quite close to the shape of a hen's egg. It stood upon its smaller end, supported by four heavy vanes that held the drivers. Above them, the bulge of the hull swelled out in the gentle curve, and about the place where the soft-boiled-egg gourmet cuts the top off of his breakfast food, the hard metal stopped and the upper curving dome of the spacecraft was made of window. Not a clear expanse of glass, but more like the greenhouse roof. Small facets set between rigid girders in a neat and efficient pattern. The girders were reasonably heavy, because each one held shutter flaps that would snap closed if the pane of glass beside it became pierced because of contact with cosmic detritus.

At the very top of this dome the glass was a smooth sheet, polished and unbroken. This section, a full ten feet in diameter, was optically perfect. For through this dome of glass the spacecraft was aimed.

If the stars actually were where they looked to be to the eye, there would have been something less of a problem. A set of precision cross-hairs set along the axis of ship's drive could be used as a line-of-sight aiming point. Like a ship near the shore, the bow could be aimed at the pier, the power set, and then the rest would take care of itself.

But stars move in their heavenly way. A poor ten to fifty miles per second can become a rather awesome gulf after four years. Alpha Centauri is a little more than four light years away. That means that the star as seen by the naked eye will be quite some distance from where it really is. Students of trigonometry will understand; a second of arc will subtend a cosmic sine at the end of four light years.

To help the pilot, the spotter was used. The spotter was a tender spacecraft that roamed the solar system far out from Sol. Two light hours away it was. When one of the star ships was scheduled to fly, the elecalc would compute the course and the big telescopes would direct the spotter spacecraft via the Z-wave until the distant ship was directly in the line of aim between Terra and the calculated spot in the heavens where the distant star would be at the end of the ship's flying time. Once the spotter was properly located, two hours before the take-off time the spotter would emit an atomic spotlight for a half hour.

Two hours later the light from this immense searchlight would arrive at Terra to provide an aiming point for the space pilot. The ship could take off on this line of sight, aiming for it directly. Of course, by the time the space travelling ship reached the spot, the spotter craft would have moved aside; the light would have ceased, and the star ship was heading for deep space with nothing to impede its course.

Paul was handicapped. The spotter was not available. Lacking the spotter to use as a point of aim, Paul was forced to choose the aiming telescope in the dome instead of the more precise cross-hairs on the optical-glass. This added to the error, and to add once more to that error was the fact that spacecraft in flight tend to revolve along their driving axis so that the angle between the true line of flight and the aiming point changed in angle. Paul would have to use Alpha Centauri itself as a point-of-aim. The correction-angle was supplied by the observatory, and applied to the aiming telescope in the dome.

A lot of minute errors that added up to a gross at the end of flight. Basically, the job of the galactic survey would remove one of the errors: That of the crude measurement of distance between the stars themselves.

Paul was a good pilot. He cut the aiming-star close and watched it in the 'scope until it disappeared. He was now in that blackness that surrounded every ship during the faster-than-light speed. He was on his way. Nothing to do for two weeks but wait for the course to end. Nothing to do but to sit and think, and plan, and dream. To think of Haedaecker and the Z-wave; to plan for the future when his discoveries brought him fame and fortune; to dream of Nora Phillips.

Paul began to hum, and after a moment or two the humming broke out into a full-throated, but dubious baritone: