"Jayne," Morris said sternly, "I've warned you about talking gibberish."

  "Oh, hush, Mordecai!" his disrespectful junior shot back, but she paused. "All right, in simple terms the problem is how Colonel Leonovna—Ludmilla—and this Troll creature can change their own past. On the face of it, the very notion negates the entire concept of causality."

  "The old 'can I kill my grandfather' thing?" Morris mused.

  "More or less. The point is, what's happening represents a significant alteration to history. Ludmilla, did your records contain any mention of what happened to Task Force Twenty-Three?"

  "No. And my hobby interest was military history. If there'd been any record of an authenticated attack on any Terran military force by UFOs, I'd've known about it, believe me."

  "So we already have a gross shift in your history," Hastings pointed out. "Presumably, the effort we'll have to mobilize to do anything effective about this Troll will have an even greater effect. If nothing else, we know these Kanga creatures exist." She smiled unpleasantly. "Knowing that, I think we can confidently assume that their reception will be even more energetic than it 'was' in your own past. But the end result will be that your universe will never come into existence at all!"

  "I know," Ludmilla said softly.

  "But if it doesn't, then you won't come back, and if you don't come back, then it will," Morris said slowly, rubbing his forehead as he tried to understand. "What do we have here—some kind of loop?"

  "That's where the Many-Worlds Theory comes in," Hastings said. "But even if Everett was right—" She shook her head. "I don't even know where to start looking for questions, much less what the answers might be!"

  "Neither does anyone where I come from," Ludmilla said wryly. "Look, the whole theory behind a Takeshita Translation is just that: theory. No one's ever tried one—or reported back afterward, anyway—and the argument over what ought to happen during one has gone on for a century and a half.

  "Jayne, you mentioned the Copenhagen School and the Many-Worlds Theory. We don't use that terminology anymore, but I know what you mean, and the fundamental problem remains, because there's still no way to test either theory." Aston and Morris looked utterly confused, and she made a face.

  "Bear with me a minute, you two," she said, "and I'll do my ignorant best to explain, all right?" They nodded, and she went on.

  "In its simplest terms, what Jayne is talking about is one of the major problems involved in understanding quantum mechanics. There's been a lot of progress since the twenty-first century, but I'm just a fighter jock." She used Aston's terminology with a wry grin.

  "Essentially, there's been a dispute over the basic nature of what we fondly call 'reality' almost since Einstein. According to the math, any possible interaction—or, rather, the result of any interaction—is a superposition of functions, each of which represents one possible outcome of the interaction. With me so far?"

  "Are you saying that mathematically speaking any of the outcomes is equally valid?" Aston sounded skeptical, and she patted his bald pate playfully.

  "For a nullwit, that's not bad," she said teasingly. "Not quite right, but it'll do for starts. You see, the problem is that for any interaction, we observe one—and only one—outcome, but the math says the potential for all possible outcomes is bound up in the event. Now, what Jayne is calling the Copenhagen School says that at the moment a wave function—" She paused and grimaced, then resumed as if re-selecting her words. "Well, at the moment an interaction occurs, the whole thing collapses into a single one of the elements of possibility, and the others never come into existence at all. The potentiality of all outcomes remains up until that moment, and none of them can be absolutely ruled out, but a weighted probability distribution can be assigned to them, which allows the effective prediction of which single event will actually occur. Follow me?"

  "Yes, but I'm losing a little ground. How about you, Mordecai."

  "Quit asking me to expose my ignorance. You were saying, Colonel?"

  "All right. An alternative hypothesis, proposed sometime in the last century, says, simply, that rather than a single event, all possible outcomes occur, however 'probable' or 'improbable' they may be. We observe only one, true, but that's because the others occur on different 'stems' of reality."

  "Parallel worlds, right?" Aston nodded. "Our sci-fi writers love 'em."

  "They still do back home," Ludmilla assured him. "Anyway, Jayne's Copenhagen School—we call it the Classic School—maintains that there is one and only one reality; a single, linear reality in which the single realized outcome of each interaction is defined and creates the preconditions for the next. What we call the Revisionist School—Jayne's 'Many-Worlds' theory—has gained a tremendous amount of ground in the last couple of hundred years, though, and some of its proponents claim that eventually they'll be able to demonstrate its validity through some esoteric manipulation of the multi-dee. I've seen the math on it, and it gives me headaches just to think about it; I certainly don't understand it. But the Revisionist School says that instead of a single reality, there are multiple realities, all branching off from a common initial source, all equally 'real,' but never interfacing."

  "So where does all this fit into time travel?" Aston asked, but a gleam in his weary eyes suggested that he saw where she was headed.

  "There are three main theories as to what happens in a Takeshita Translation," Ludmilla said. "One says that the whole thing is impossible; anyone who tries one simply goes acoherent and stays there. It's neat, at least, but my survival is empirical evidence that it doesn't work.

  "Theory number two is Takeshita's First Hypothesis, and it says that anyone making a Takeshita Translation travels backward along the single reality stem of the Classic School. There are some problems with it, but, essentially, it says that when the traveler stops moving—drops back into phase with reality, as it were—he becomes an event which has been superimposed upon the reality stem. He, personally, exists, wherever he came from and however he got there. But since he exists, he can affect the universe, which will inevitably affect the nature of reality 'downstream' from him, with the result that—as Commander Morris put it—you really could murder your grandfather without erasing yourself. Your existence is pegged to a reality which preexists the one in which you were never born.

  "Takeshita spent years on the math to support that theory, but in the last years of his life he became convinced that the Revisionists had been right all along, which created a furor amongst his followers, I can tell you! Anyway, he propounded his Second Hypothesis, which says, essentially, that the classic arguments against paradox are valid after all—that it's impossible for an individual to move into his own past. By the act of moving backward in time, he does, indeed, superimpose his existence on events, but, in the process, he causes the stream of reality to split off another tributary. In effect, he avoids paradox by forcing a divergence of 'his' subsequent personal reality line from the one which created him.

  "The problem, of course," she ended with a whimsical smile, "is that no hard experimental data was ever available. Until now, that is."

  Silence threatened to stretch out indefinitely until Jayne Hastings finally broke it.

  "So which theory's correct?" she asked softly.

  "Let's start with the basics," Ludmilla suggested. "I am here—and so is the Troll. Task Force Twenty-Three was attacked and did shoot down two Troll fighters. Those facts seem to prove that whatever happened is possible, and, further, that the Troll can do whatever it intends to do unless we stop it. Those are the pragmatic considerations. Agreed?"

  Three heads nodded, and she went on.

  "All right. My own feeling is that Takeshita's Second Hypothesis applies, which means that the Revisionists were right, of course. And it also means that I'm not in my past, which neatly explains the absence of any recorded nuclear attack on a US Navy task force in 2007. It didn't happen in my reality—it happened in yours."

  "You mean . . . you're n
ot just from the future, you're from someone else's future?" Aston sounded a bit shaken.

  "Why not? Nick Miyagi could have explained it a lot better—he always did support the Second Hypothesis." Ludmilla smiled sadly. "He almost took time to argue the point with me when we saw it happening. But, yes, that's right. I'm not from your reality—your 'universe'—at all, Dick."

  "But . . ." Hastings frowned as she worked through the implications. "Excuse me again, but you seem to be saying you more than half-expected the Kangas to wind up in somebody else's past."

  "I did."

  "Then why try to stop them?" Hastings asked very quietly. "You say your battle division was totally destroyed, along with thousands and thousands of your people. Your own fighter squadron was destroyed—in fact, you're the only survivor from your entire force. Why in God's name take such losses when these 'Kangas' couldn't even hurt your time line at all?"

  "Two reasons, really, I suppose," Ludmilla said after a moment. "First, of course, we couldn't be certain. Remember, Takeshita offered two hypotheses, and neither had ever been tested. What if he'd been right the first time, and the Kangas had changed our own history?" Hastings nodded slowly, but the question remained in her eyes, and Ludmilla smiled sadly.

  "Then there was the second reason," she said softly. "Whoever's past they wound up in, we knew there was going to be a human race in it. Not our own ancestors, perhaps, but still an entire planet full of human beings. Commodore Santander and I never actually discussed it, but we didn't have to. We know what Kangas and Trolls are like. There was no way we could have lived with ourselves if we'd let them murder our entire race in any time line."

  Silence hovered in the compartment, and Aston reached out to clasp her hand. She returned his grip tightly enough to hurt—tightly enough to give the lie to her calm expression—and his heart ached for her. She wasn't simply adrift in time; she was adrift in a totally different, utterly alien universe, where none of the worlds she'd known would ever even come into existence. And she was the one—and only—creature of her kind who would ever exist here.

  She looked at him for a moment, then smiled. He recognized the courage behind that bright, cheerful expression, but no hint of her total aloneness showed in her voice as she looked back at Hastings.

  "And wherever I am, and however I got here, Commander, you've got a Troll on your hands, don't you?" Hastings nodded, and Ludmilla shrugged. "Well, that's something I understand in anyone's universe, and killing Trolls is what I do. So what do you say we put our heads together and figure out how to kill this one."

  CHAPTER FIFTEEN

  deception n. 1. The use of deceit. 2. State or fact of being deceived. 3. Ruse; trickery; imposture. [Middle English decepcioun, from Latin decipere, to deceive.]

  —Webster-Wangchi Unabridged Dictionary of Standard English Tomas y Hijos, Publishers

  2465, Terran Standard Reckoning

  The office of Vice Admiral Anson McLain, Commander in Chief Atlantic Fleet, was almost stark. Furniture was sparse, and the walls bore none of the usual outsized portraits of sailing ships or World War Two carriers fighting off kamikazes. Instead, they were adorned with framed photos of the sleek, high-tech warships of Admiral McLain's early twenty-first-century fleet, although a beautiful painting of two of the Iowa-class battleships which had recently been stricken at last to become memorial ships held pride of place behind his oversized desk.

  McLain was tough as nails, young for his rank, and black. Regarded by some as the most brilliant naval officer of his generation, he'd paid his dues to crack the traditionally white ranks of the Navy's senior flag officers by being, quite simply, the best there was, of any color. He was a carrier man, a highly decorated pilot with four kills over the Persian Gulf, who had outraged big-ship aviators by supporting construction of Seawolf attack subs and supersonic V/STOL fighters at the expense of a thirteenth Nimitz-class carrier. That was typical of him, Commander Morris thought; Anson McLain did what he thought right, whatever the cost and without a trace of hesitation.

  But at the moment, CINCLANT wore a definitely harassed look. Roosevelt was in for repairs, reducing his total deployable flight decks by a sixth, and two more CVNs had been diverted to watch the extremely nasty Falklands situation. Which left McLain's carriers understrength by half for normal deployments at a moment when the Balkans were heating up again. The fact that the People's Republic of China had just commissioned its second carrier didn't help matters one bit, but McLain, the CNO, and the JCS had twisted CINCPAC's arm hard enough to get the newest Nimitz, USS Midway, transferred from Pearl Harbor to the Atlantic. She was en route to reinforce him now, but for the present, he was stretched thin, indeed.

  Far worse, Anson McLain had lost people. He was a cool, analytical man, but he was also implacable. Somehow, someday, he would discover who or what had killed or blinded a thousand of his people, and when he did—

  Which explained the fiery light in his normally calm eyes.

  "Well, Mordecai," he said mildly, standing and holding out his hand, "I hope your little jaunt was productive."

  "It was, Sir," Morris replied as CINCLANT released his hand and gestured to a chair. "Captain Aston does know what happened, and why."

  "I'm glad to hear that," McLain said softly, and his tone made Morris shiver. It reminded the commander forcibly of Colonel Ludmilla Leonovna. "But what, if you'll pardon my asking, was all the mystery about?"

  "That, Sir, is going to be a bit hard to explain," Morris said slowly. He and Jayne Hastings had spent an intense twenty-four hours with Aston and Ludmilla, hammering out what needed to be done, and Morris was only too well aware how much depended on McLain's reaction. He knew his boss better than most, but he also knew what he was about to ask CINCLANT to believe.

  "Then you'd better start, M&M," McLain said simply, and the commander drew a deep breath.

  "Yes, Sir. To begin with . . ."

  Unlike anyone else to whom the story had yet been told, Admiral McLain sat silently, elbows on his desk, chin on the backs of his interlaced fingers, without a single question. CINCLANT hated people who interrupted to demonstrate their own cleverness rather than waiting for the briefing officer to cover the points they were raising, but Morris found it a bit unnerving that the admiral could listen to this story with his usual calm.

  He reached the end and stopped, painfully aware of how insane the whole thing sounded. McLain regarded him expressionlessly for a moment, toying with a presentation coffee mug from the crew of his last seagoing command. He ran a dark fingertip over the raised crest of the CVN Harry S. Truman and pursed his lips, then leaned well back in his swivel chair.

  "A good brief, Mordecai," he said finally, steepling his fingers across his flat, hard belly muscles. "I only have one question."

  "Sir?" Morris asked, hoping he looked less anxious than he felt.

  "Do you believe a word of it?"

  "Yes, Sir. I do." Morris met the admiral's eyes levelly.

  "And this Colonel Leonovna is available to answer questions directly?"

  "Yes, Sir." Morris was baffled by McLain's calm reaction. "Of course, we—Captain Aston and I, that is—are keeping her under wraps."

  "How so?"

  "We put her on a MAC flight as a Navy dependent and flew her into Virginia Beach, then hustled her out of sight. She and Captain Aston are at my home right now, keeping a very low profile."

  "Really?" McLain smiled for the first time since Morris had begun his report. "And how is your wife taking all this?"

  "Rhoda thinks Colonel Leonovna is Captain Aston's niece, Sir. We don't know what her EEG looks like."

  "Um." CINCLANT pursed his lips again. "You are aware of just how incredible this all sounds, aren't you, M&M?"

  "Yes, Sir. All I can tell you is what I believe to be the truth, Sir. That's what you pay me for."

  "I see. All right, then, first things first," McLain said calmly, and reached for the phone on his desk. He punched in a number with slow deliberation and
waited for an answer.

  "Good afternoon," he said into the phone after a moment, swinging his chair slightly from side to side, "this is Admiral McLain. Please inform Admiral Horning that I must speak with him for a moment." He paused for a few seconds, and his face hardened slightly. "I'm sorry, Lieutenant," he said levelly, "but you're just going to have to interrupt them, then."

  Morris tried to appear calm. Admiral Franklin Horning was the Surgeon General of the United States, and the commander could think of several unpleasant reasons for his boss to seek a medical opinion.

  "Frank?" McLain leaned forward in his chair, and his eyes rested on Morris's face. There might have been the hint of a twinkle in them, Morris thought anxiously, as if the admiral could read his mind and was amused by what he was thinking. "Sorry to interrupt your conference, but I need a favor. I warn you—it's going to sound a little strange." He paused as Admiral Horning said something in reply, then chuckled. "Nope, stranger. You see, Frank, I need to see the President's EEG."

  Morris had no idea of exactly how Horning responded to that, but as the commander sagged in his chair in relief, McLain winced and moved the phone away from his ear.

  The Troll felt a slow, familiar throb of rage. His fragmentary information from Captain Santiago had not included the fact that so many radar stations guarded the Panama Canal Zone, and he'd been forced well out over the Pacific to avoid them, only to find the entire western coast of this "United States" covered by a seemingly solid belt of radar emissions. For a moment he'd wondered if they had somehow learned of his coming, but then he'd noted the large numbers of crude aircraft in evidence. So it was some sort of navigational control system, was it? Or, he amended, some of it was, anyway, for on a world so riddled with national competition and suspicions, there had to be military installations, as well.

  The need to avoid detection by such primitives infuriated him. The hunger for destruction was upon him once more, and he longed for a few of the ARADs his dead masters had expended upon that never-to-be-sufficiently-accursed naval task force, but he mastered his fury sternly. Time enough for that, he reminded himself. Time enough when he knew more. When he was ready. For now he must be cautious.