by James Blish
"Fixed orbit around what, Mr. Spock?"
"The Earth, sir. I am at present unable to say how we got here."
"Screen on," Kirk said.
The screen came on. It was the Earth below them, all right.
"We're too low in the atmosphere to retain this altitude," Spock said. "Engineer reports we have enough impulse power to achieve escape velocity."
"Helm, give us some altitude."
"Yes, sir," Sulu said. "Helm answers. She's sluggish, sir."
"Sir," Uhura said. "Normal Starfleet channel has nothing on it but static. I'm picking up something on another frequency, but it's not identifiable."
"Put it on audio, Lieutenant."
Uhura flicked a tumbler and the loudspeaker on her board burst out: ". . . five-thirty news summary. Cape Kennedy—the first manned moon shot is scheduled for Wednesday, six a.m., Eastern Standard Time. All three astronauts set to make this historic flight are . . ."
Kirk was up out of his chair on the instant. "The first manned moon shot!" he said. "You've got some sort of dramatization. That shot was back in the 1970s."
Uhura nodded and tried another channel, but from the computer, Spock said slowly: "Apparently, Captain, so are we."
"Mr. Spock, this is no time for joking."
"I never joke," Spock said severely. "At present I have only rough computations, but apparently what we hit was the subspace component of an intense spherical gravity field, very likely a black star. The field translated our momentum in terms of time—a relativistic effect. I can give you an exact reading in a few moments, but 1970 seems to be of about the right order of magnitude."
Kirk sat down again, stunned. Uhura continued scanning. Finally she said, "Captain, I'm picking up a ground-to-air transmission in this sector."
"Verified," Spock said. "Our scanners are picking up some kind of craft approaching from below us, under cloud cover and closing fast."
The loudspeaker said: "Blue Jay Four, this is Black Jack. We're tracking both you and the UFO."
"I have him on my screen," another voice said. "Following."
"Good, let's get this one for once."
"Mr. Sum," Kirk said, "can we gain altitude faster?"
"I'm trying, sir, but she's still slow in responding."
"Blue Jay Four, have you got visual contact yet?"
"I can see it fine," said the second voice. "And it's huge too. As big as a cruiser, bigger maybe. It is saucer-shaped, but there're two cylindrical projections on top and one below."
"We have two more nights scrambled and on the way," said the first voice. "They'll rendezvous with you in two minutes."
"Won't be here, Black Jack. The UFO is climbing away fast."
"Blue Jay Four, close on the object and force it to land. We want it down—or at least disabled until the other planes arrive. After thirty years of rumors, this may be our first clear shot."
"Acknowledged. Closing in."
"Can he harm us?" Kirk said.
"I would judge so, Captain," Spock said. "The aircraft is an interceptor equipped with missiles, possibly armed with nuclear warheads. Since we do not have the power for a full screen, he could at least damage us severely."
"Scotty!" Kirk said into his microphone. "Activate tractor beam. Lock onto that aircraft and hold it out there."
"Captain," Spock said, "that type of aircraft may be too fragile to take tractor handling."
"Tractor on, sir," Scott's voice said briskly. "We have the target."
Spock looked into his hooded viewer and shook his head. "And it is breaking up, Captain."
"Transporter room! Can you lock on the cockpit of that aircraft?"
"No problem, Captain."
"Beam that pilot aboard," Kirk said, springing up. "Spock, take over."
The figure who materialized in the transporter chamber was a strange sight to Kirk until he removed his oxygen mask and helmet. Then he was revealed as a medium-tall, compactly built man with an expression of grim determination despite his obvious amazement. He would have made a good starship crewman, Kirk thought . . . centuries from now.
"Welcome to the Enterprise," Kirk said, smiling.
"You . . . you speak English!"
"That's right," Kirk said. "You can step down from our transporters, Mr. . . .?"
"Captain John Christopher," the pilot said stiffly. "United States Air Force, serial number 4857932. And that's all the information you get."
"Relax, Captain. You're among friends. I'm Captain James T. Kirk, and I apologize for bringing you aboard so abruptly. But we had no choice. I didn't know your ship couldn't hold up under our tractor beam until it was too late."
"Don't give me any double-talk," Christopher said. "I demand to know . . ."
"You're in no position to demand anything, but we'll answer all your questions anyhow in good time. Meanwhile, relax. You're our guest. I have a feeling you'll find it interesting."
He led the way out of the transporter room. Christopher shrugged and followed. As they moved down the corridor, he was obviously missing nothing; clearly a trained observer. When a pretty young crew-woman carrying a tricorder went past them, however, he had trouble retaining his composure. "Passenger?" he said.
"No, crew. About a fourth of the crew is female—exactly a hundred at the moment."
"A crew of four hundred?"
"Four hundred and thirty. Now if you'll step aboard the elevator . . ."
Christopher did, and was immediately startled once more when it moved horizontally instead of up or down. After digesting this peculiarity, he said:
"It must have taken quite a lot of money to build a ship like this."
"Indeed it did. There are only twelve like it in the fleet."
"The fleet? Did the Navy . . .?"
"We're a combined service, Captain," Kirk said. "Our authority is the United Federation of Planets."
"Federation of—Planets?"
"That's right. Actually, Captain—this is a little difficult to explain. We . . . we're from your future. A time warp landed us back here. It was an accident."
"You people seem to have a lot of them," Christopher said drily, "if all the UFO reports stem from the same kind of source. However, I can't argue with the fact that you are here, ship and all." While he spoke, the elevator doors snapped open to reveal the bridge, with Spock in the command chair. "And I've never believed in little green men."
"Neither have I," Spock said, rising.
This time Christopher made no attempt to conceal his astonishment. And Spock claims he never jokes, Kirk thought; but he said only, "Captain Christopher, this is my first officer, Commander Spock."
"Captain," Spock said with an abrupt but courteous nod.
"Please feel free to look around the bridge, Captain. I'm sure you have the good sense not to touch anything. I think you'll find it interesting."
" 'Interesting,'" Christopher said, "is not a very adequate word for it." He moved over toward the communications and library-computer stations, but could not help shooting another look at Spock as he did so. Kirk did not explain; everybody else on board took the half-alien first officer as a matter of course, and Christopher might as well practice doing the same; he might be with them for quite a while yet.
"We have achieved a stable orbit out of Earth's atmosphere, Captain," Spock said. "Our deflector shields are operative now, and ought to prevent us from being picked up again as a UFO." He made a grimace of distaste over the word. "Mr. Scott wishes to speak to you about the engines."
"Very well, Mr. Spock. I know that expression. What else is on your mind?"
"Captain Christopher."
Kirk looked toward the newcomer. He was talking to Uhura; the spectacle of a beautiful Bantu girl operating a communications board evidently had diverted him, at least temporarily, from the first officer.
"All right, what about him?"
"We cannot return him to Earth," Spock said. "He already knows too much about us and is learning more. I mean no a
spersions on his character, about which I know nothing, but suppose an unscrupulous man were to gain possession of the knowledge of man's certain future, as represented by us? Such a man could speculate—manipulate key industries, stocks, even nations—and in doing so, change what must be. And if it is changed, Captain, you and I and everything we know might be made impossible."
"We'd just vanish? Including thousands of tons of Enterprise?"
"Like a soap bubble."
"Hmm. You know, Spock, your logic can be very annoying." Kirk looked back at Christopher. "That flight suit must be uncomfortable. Have the quartermaster issue Captain Christopher some suitable clothes—tactfully relieving him of any sidearms he may be carrying in the process—and then I want to see you and him in my quarters."
"Yes, sir."
Kirk was talking to the computer when they came in; he waved them to seats. "Captain's log, supplemental. Engineering Officer Scott reports warp engines damaged but repairable. Ascertain precise degree and nature of damage, compute nature and magnitude of forces responsible, and program possible countermeasures."
"Affirm; operating," said the computer's voice in mid-air. Christopher did not react; evidently he was getting used to surprises.
"Kirk out. Now, Captain, we have a problem. To put the matter bluntly, what are we going to do with you? We can't put you back."
"What do you mean, can't? Mr. Spock here tells me that your transporter can work over even longer distances than this."
"It's not the transporter," Kirk said. "You know what the future looks like, Captain. If anybody else finds out, they could change the course of it—and destroy it."
"I can see that," Christopher said after a moment. "But it also strikes me that my disappearance would also change things."
"Apparently not," Spock said. "I have run a computer check through all historical tapes. They show no relevant contribution by any Captain John Christopher. There was a popular author by that name, but it was a pen name; you are not he."
Christopher was visibly deflated, but not for long. He stood and began to pace. Finally he swung back toward Kirk.
"Captain," he said, "if it were only a matter of my own preference, I'd stay. I'd give my right arm to learn more about this ship—all about it. It's a colossal achievement and obviously it implies even greater ones in the background. But my preference doesn't count. It's my duty to report what I've seen. I have an oath to uphold." He paused, then added pointedly: "What would you do?"
"Just that," Kirk said. "I entirely understand. You are the kind of man we recruit for our own service, and can never get enough of, though we don't have oaths any more. But unfortunately, this means that you are also of superior intelligence. We cannot risk any report that you might make."
"I have a wife and two children," Christopher said quietly. "I suppose that makes no difference to you."
"It makes a lot of difference to me," Kirk said. "But I cannot let it sway me."
"In both your trades—the pilot and the warrior—there was always an unusually high risk that you would become a casualty," Spock said. "You knew it when you married; so did your wife. You bet against the future, with high odds against you. Unfortunately, we are the future and you have lost; you are, in effect, now a casualty."
"Mr. Spock is no more unfeeling than I am," Kirk added. "But logic is one of his specialties, and what he says is quite true. I can only say I'm sorry, and I mean it." The intercom interrupted him. "Excuse me a moment. Kirk here."
"Engineer here, Captain. Everything's jury-rigged, but we're coming along with the repairs and should be ready to reenergize in four hours."
"Good. Scotty, you can fix anything."
"Except broken hearts, maybe. But, sir . . ."
"What is it? Plow right ahead."
"Well, sir," Scott's voice said, "I can fix the engines, but I canna build you a time machine. We'll be ready to go, but we've no place to go in this era. Mister Spock tells me that in the 1970s the human race was wholly confined to the Earth. Space outside the local group of stars was wholly dominated by the Vegan Tyranny, and you'll recall what happened when we first hit them. D'ye see the problem?"
"I'm afraid," Kirk said heavily, "that I do. Very well, Mr. Scott, carry on."
"Yes, sir. Out."
Christopher's face was a study in bitter triumph; but what he said next, oddly, was obviously designed to be helpful—or at least, to establish that his own hope was well-founded.
"Mr. Spock here tells me that he is half Vulcan. Surely you can reach Vulcan from here. That's supposed to be just inside the orbit of Mercury."
"There is no such solar planet as Vulcan," Kirk said. "Mr. Spock's father was a native of The Vulcan, which is a planet of 40 Eridani. Of course we could reach that too . . ."
". . . but in the 1970's," Spock finished. "If we took the Enterprise there, we would unwrite their future history too. Captain, this is the most perfect case of General Order Number One that I have ever encountered—or think I am likely to encounter."
"The order," Kirk explained to Christopher, "prohibits interference with the normal development of alien life and alien societies. It hadn't occurred to me until Mr. Spock mentioned it, but I'm sure it would be construed to apply here too."
"Too bad, Captain," Christopher said. He was not bothering to conceal his triumph now. "Maybe I can't go home—but neither can you. You're as much a prisoner in time as I am on this ship."
"I believe, sir," Spock said, "that Captain Christopher's summary is quite exact."
It was indeed exact, but not complete, as Kirk quickly realized. There was also the problem of supplies. The Enterprise could never land on any planet—and certainly would not dare to land on this one, its own home world, even if it were possible—and it was simply ridiculous to even consider trying to steal food, water and power by gig or transporter for 430 people. As for Christopher—who had already tried to escape through the transporter and had come perilously close to making it—what prospects did he have if the Enterprise somehow did get back to its own time? He would be archaic, useless, a curiosity. Possibly he could be retrained sufficiently to find a niche, but never retrained to forget his wife and children. To check that, Kirk visited McCoy, the ship's surgeon.
"Get him down here and I'll check," McCoy said.
Kirk put in the call. "You mean it might be done?"
"It depends upon the depth of his commitment. Some marriages are routine. I'll have to see what the electroencephalograph shows."
"You're starting to sound like Spock."
"If you're going to get nasty, I'll leave." Kirk grinned, but the grin faded quickly. "If the depth of his commitment is crucial, we're sunk. He's the kind who commits himself totally. Witness yesterday's escape attempt."
Spock came in with the prisoner—after the escape attempt, there was no other honest word for it. He said at once:
"Captain, I do not know what Dr. McCoy has in mind, but I think it may be useless by now; I have some new information. I find I made an error in my computations."
"This," McCoy said drily, "could be a historic occasion."
Spock ignored the surgeon. "I find that we must return Captain Christopher to Earth after all."
"You said I made no relative contributions." Christopher said sourly.
"I was speaking of cultural contributions. I have now checked the genetic contributions, which was a serious oversight. In running a cross-check on that factor, I discovered that your son, Colonel Shaun Geoffrey Christopher, headed . . . will head the first successful Earth—Titan probe, which is certainly significant. If Captain Christopher is not returned, there won't be any Colonel Christopher to go to the Saturnian satellites, since the boy does not yet exist."
The grin on Christopher's face made him look remarkably like a Halloween pumpkin. "A boy," he said, to nobody in particular. "I'm going to have a son."
"And we," McCoy said, "have a headache."
"No," Kirk said. "We have an obligation. Two obligatio
ns, mutually antagonistic."
"It is possible that we can satisfy both of them at once," Spock said.
"How? Out with it, man!"
"I have the data you ordered the computer to work out, and there is now no question but that the only reason we are here at all is because we had a head-on collision with a black star. To get back home, we are going to have to contrive something similar."
"Do you know of any black stars around here? And how will that solve our problem with Captain Christopher?"
"There is a black star quite nearby, in fact, Captain, but we cannot use it because it is well out of transporter range of Earth. That would prevent our returning Captain Christopher. But Engineering Officer Scott thinks we may be able to use our own sun. It will, he says, be a rough ride, but will also offer us certain advantages. Briefly, if we make a close hyperbolic passage around the sun at warp eight . . ."
"Not with my ship," Kirk said coldly.
"Please, Captain, hear me out. We need the velocity because we must compensate for the Sun's relatively weak gravitational field. And I spoke of advantages. What will happen, if nothing goes wrong, is that we will retreat further into time as we reach the head of the hyperbola . . ."
"Just what we need," McCoy said.
"Shut up, Bones, I want to hear this."
". . . and as we mount the other leg of the curve, there will be a slingshot effect that will hurl us forward in time again. If this is most precisely calculated, we will pass within transporter range of the Earth within two or three minutes before the time when we arrived here the first time, before we first appeared in the sky. At that moment, we reinject Captain Christopher into his plane—which will not have been destroyed yet—and the whole chain of consequences will fall apart. Essentially, it will never have happened at all."
"Are you sure of that?"
Spock raised his eyebrows. "No, sir, of course I am not sure of it. Mr. Scott and I think it may work. The computer concurs. Certainty is not an attainable goal in a problem like this."
