A Bridge of Years

  She nodded. "That would be nice. This is kind of weird, you know. We hardly know each other, but we're nursemaiding this—person out of a time machine."

  "We know each other all right," Archer said. "It doesn't take that long. I'm a semi-fucked-up real estate agent living in this little town he kind of loves and kind of hates. You're a semisuccessful painter from Seattle who misses her grandmother because she never had much of a family. Neither of us knows what to do next and we're both lonelier than we want to admit. Does that about sum it up?"

  "Not a bad call." She smiled a little forlornly and uncorked a bottle of wine.

  The night after that she went to bed with him.

  The bed was a creaky, pillared antique in what Catherine called the guest room, off the main hall upstairs. The sheets were old, thin, delicate, cool; the mattress rose around them like an ocean swell.

  Catherine was shy and attentive. Archer was touched by her eagerness to please and did his best to return the favor. Archer had never much believed in one-night stands; great sex, like great anything, required a little learning. But Catherine was easy to know and they came together with what seemed like an old familiarity. It was, in any case, Archer thought, a hell of an introduction.

  Now Catherine drifted to sleep beside him while Archer lay awake listening to the silence. It was quiet up here along the Post Road. Twice, he heard a car pass by outside—one of the locals, home late; or a tourist looking for the highway.

  There were big questions that still needed answering, he thought. Archer thought about the word "time" and how strange and lonely it made him feel. When he was little his family used to drive down to his uncle's ranch outside Santa Fe in New Mexico, dirt roads and the Sangre de Cristo Mountains in the distance, scrub pines and sage brush and ancient pueblos. The word "time" made him feel the way those desert roads used to make him feel: lost in something too big to comprehend. Time travel, Archer thought, must be like driving those roads. Strange rock formations and dust devils, and an empty blank horizon everywhere you look.

  When he woke, Catherine was dressing herself self-consciously by the bed. He turned away politely while she pulled on her panties. Archer sometimes wondered whether there was something wrong with him, the doubtful way women always looked at him in the morning. But then he stood up and hugged her and he felt her relax in his arms. They were still friends after all.

  But something was different today and it was not just that they had gone to bed last night. Something in this project was less miraculous now, more serious. They knew it without talking about it.

  After breakfast they hiked down to the Winter house to visit Ben Collier.

  The steaks from the Safeway had been doing him good. Ben was sitting up in bed this morning, the blankets pooled around his waist. He looked as cheerful as a Buddha, Archer thought. But it was obvious from the he of the bedclothes that his leg was still missing.

  Archer believed the stump was a little longer, though. It occurred to him that he expected the time traveler to grow a new leg—which apparently he was doing.

  "Morning," Archer said. Catherine stood beside him, nodding, still a little frightened.

  Ben turned his head. "Good morning. Thank you for coming by."

  Archer began to deliver the speech he'd been rehearsing: "We really have to talk. Neither of us minds coming down here. But, Ben, it's confusing. Until we know what's really going on—"

  Ben accepted this immediately and waved his hand: no need to continue. "I understand," he said. "I'll answer all your questions. And then—if you don't mind—I'll ask you one."

  Archer said that sounded fair. Catherine brought in two chairs from the kitchen, on the assumption this might take a while.

  □ □

  □ □

  "Who are you really," Archer asked, "and what are you doing here?"

  Ben Collier wondered how to|respond to this.

  Confiding in these people was a radical step . . . but not entirely unprecedented, and unavoidable under the circumstances. He was prepared to trust them. The judgment was only partially intuitive; he had watched them through his own eyes and through the more discerning eyes of his cybernetics. They showed no sign of lying or attempting to manipulate him. Archer, in particular, seemed eager to help. They had weathered what must have been a frightening experience, and Ben credited that to their favor.

  But they would need courage, too. And that quality was harder to judge.

  He meant to answer their questions as honestly and thoroughly as he could. He owed them this, no matter what happened next. Catherine could have made things infinitely more difficult when she discovered him in the shed—if she had called the police, for instance. Instead, his recovery had been hastened by a significant margin. It would have been pointless and unkind to lie about himself.

  He was born (he explained) in the year 2157, in a small town not far from the present-day site of Boulder, Colorado. He had lived there most of his professional life, doing research for a historical foundation.

  All this begged the definition of "small town," of "professional life," and of "historical foundation" as these things would be understood by Archer and Catherine—but they were close enough to the truth.

  Catherine said, "That's how you became a time traveler?"

  He shook his head. "I was recruited. Catherine, if you visited the twenty-second century you would find a lot of marvelous things—but time travel is not among them. Any reputable physicist of my own era would have rejected the idea out of hand. Not the idea that time is essentially mutable and perhaps nonlinear, but the idea that it could be traversed by human beings. The water in the ocean is like the water in a swimming pool, but you can't swim across it. I was recruited by individuals from my own future, who were recruited by others from their future—and so on."

  "Like stepping stones," Archer supplied.

  "Essentially."

  "But recruited for what?"

  "Primarily, as a caretaker. To live in this house. To maintain it and protect it."

  "Why?" Catherine asked, but he imagined she had already surmised the answer.

  "Because this house is a sort of time machine."

  "So you're not a real time traveler," Archer said. "I mean, you come from the future . . . but you're only a kind of employee."

  "I suppose that's a good enough description." "The machine in this building isn't working the way it's supposed to—am I right?" He nodded.

  "But if it was, and you were the custodian, who would come through here? Who are the real time travelers?"

  This was a more serious question, more difficult to answer. "Most of the time, Doug, no one would come through. It's not a busy place. Mainly, I collect contemporary documents —books, newspapers, magazines—and pass them on."

  "To whom?" Catherine asked.

  "People from a time very distant from my own. They look human, but they aren't entirely. They created the tunnels— the time machines."

  He wondered how much sense they would make of this. The real time travelers,' Archer had said: as good a description as any. Ben always trembled a little on the occasions when he was required to interact with these beings. They were kindly and only somewhat aloof; but one remained conscious of the evolutionary gulf. "Please understand, much of this is as far beyond my comprehension as it may be beyond yours. All I really know are legends, passed down by people like myself—other custodians, other caretakers. Legends of the future, you might say."

  "Tell us some," Archer said.

  What this concerns (Ben explained) is life on earth.

  Look at it in the context of geologic time.

  In the primeval solar system the earth is fused into coherent shape by the collisions of orbiting planetesimals. It has a molten core, a skin of cooler rock. It exudes gases and liquids —carbon dioxide, water. In time, it develops an atmosphere and oceans.

  Over the course of millions of years, life of a sort arises as vermiform crystalline structures in the porous rock
of hot mineral-dense undersea vents. In time, these crystalline structures adapt to a cooler environment by incorporating proteins into themselves—so successfully that the crystalline skeleton is discarded and purely proteinoid life comes to dominate the primitive biosphere. RNA and DNA are adopted as a genetic memory and evolution begins in earnest.

  An almost infinite diversity of structures compete against the environment. There will never again be such complexity of life on earth—the rest of evolution is a narrowing, a winnowing out.

  The climate changes. Prokaryotic cells poison the atmosphere with oxygen. Continents ride tectonic plates across the magma. Life flows and ebbs in the long intervals between cometary impacts.

  Mankind arises. It turns out that mankind, like the grasses, like the flowering plants, is one of those species capable of transforming the planet itself. It alters the climatic balance and might well have drowned in its own waste products, except for an extraordinary new ability to modify itself and to create new forms of life. These are parallel and complementary technologies. Mankind, dying, learns to make machines in its own image. It learns to change itself in fundamental ways. The two capabilities combine to generate a new form of life, self-reproducing but only marginally biological. It can be called human because there is humanity in its lineage; it's the legitimate heir of mankind. But it's as different from mankind as crystalline life from the rocks it was born in, or protein life from the rocky structures that preceded it. These new creatures are almost infinitely adaptable; some of them live in the ocean, some of them live in outer space. In their diaspora they occupy most of the planets of the solar system. They are very successful. They begin to comprehend, and eventually manipulate, some fundamental constants of the physical universe. They visit the stars. They discover hidden structures in the fabric of duration and distance.

  Ben paused, a little breathless. How long since these mysteries had been explained to him? Years, he thought—no matter how you measure it. "Catherine," he said, "would you open the window? There's a nice breeze outside." A little dazedly, she rolled back the blinds and lifted the window. "Thank you," Ben said. "Very pleasant."

  Archer was frowning. "These new creatures,' these are the folks who travel in time?"

  "Who built the machine that operates in this house, yes. You have to understand what time travel means, in this case. They discovered what might be called crevices in the structure of space and time—fractures, if you like, with a shape and duration outside the definable bounds of this universe but intersecting it at certain points. A 'time machine' is a sort of artificial tunnel following the contour of these crevices. In the local environment of the earth, a time machine can only take you certain places, at certain times. There are nodes of intersection. This house—an area surrounding it for some hundreds of yards—is one of those nodes."

  Archer said, "Why here?"

  "It's a meaningless question. The nodes are natural features, like mountains. There are nodes that intersect the crust of the earth under the ocean, nodes that might open in thin air."

  "How many places like this are there, then?"

  Ben shrugged. "I was never told. They tend to cluster, both in space and in time. The twentieth century is fairly rich in them. Not all of them are in use, of course. And remember: they have duration as well as location. A node might be accessible for twenty years, fifty years, a hundred years, and then vanish."

  Catherine had been sitting in patient concentration. She said, "Let me understand this. People a long way in the future open a pathway to these nodes, yes?"

  Ben nodded.

  "But why? What do they use them for?" "They use them judiciously for the purpose of historical reclamation. This century—and the next, and my own—are the birthing time of their species. For them, it's the obscure and distant past."

  "They're archaeologists," Catherine interpreted.

  "Archaeologists and historians. Observers. They're careful not to intervene. The project has a duration for them, also. Time passes analogously at both ends of the link. They're conducting a two-hundred-year-long project to restore their knowledge of these critical centuries. When they're finished, they mean to dismantle the tunnels. They're nervous about the mathematics of paradox—it's a problem they don't want to deal with."

  Catherine said, "Paradox?"

  Archer said, "A time paradox. Like if you murder your own grandfather before you're born, do you still exist?"

  She regarded him with some astonishment. "How do you know that?"

  "I used to read a lot of science fiction."

  Ben said, "I'm told there are tentative models. The problem isn't as overwhelming as it seems. But no one is anxious to put it to the test."

  Archer said, "Even the presence of somebody from the future might have an effect. Even if they just crush a plant or step on a bug—"

  Ben smiled. "The phenomenon isn't unique to time travel. In meteorology it's called 'sensitive dependence on original conditions.' The atmosphere is chaotic; a small event in one place might generate a large effect in another. Wave your hand in China and a storm might brew up in the Atlantic. Similarly, crush an aphid in 1880 and you might alter the presidential election of 1996. The analogy is good, Doug, but the connection isn't precisely causal. There are stable features in the atmosphere that tend to recur, no matter what—"

  "Attractors," Archer supplied.

  Ben was pleased. "You keep up with contemporary math?"

  Archer grinned. "I try."

  "I've been told there are similar structures in historical time—they tend to persist. But yes, the possibility for change exists. It's an observer phenomenon. The rule is that the present is always the present. The past is always fixed and immutable, the future is always indeterminate—no matter where you stand."

  "From here," Archer said, "the year 1988 is unchangeable"

  "Because it's the past."

  "But if I traveled three years back—"

  "It would be the future, therefore unpredictable."

  "But there's your paradox already," Archer said. "It doesn't make sense."

  Ben nodded. He had struggled with this idea himself . . . then submitted to it, a Zen paradox which happened to be true and therefore inarguable. "It's the way time works," he said. "If it doesn't make sense, it's because you haven't made sense of it."

  "You said there was a math for this?"

  "So I'm told."

  "You don't know it?"

  "It's not twenty-second-century math. It's several millennia beyond that. I doubt you or I could contain it without a certain amount of neural augmentation."

  Catherine said, "This is awfully abstract."

  Archer nodded and seemed to struggle a moment with his thoughts.

  Ben looked out the window. There was something wonderfully calming about all these Douglas firs. The sound they made when the wind moved through them.

  Archer cleared his throat. "There's another obvious question."

  The painful question. "You want to know what went wrong."

  Archer nodded.

  Ben sighed and took a breath. He didn't relish these memories.

  He had reconstructed this from his own experience, from the fragmentary memories of the cybernetics, from the evidence of the tunnel itself.

  There was a house like this house, he told Archer and Catherine, a temporal depot, in the latter half of the twenty-first century, in Florida—in those days a landscape of fierce tropical storms and civil war.

  The custodian of that house was a woman named Ann Heath.

  (Ann, he thought, I'm sorry this had to happen. You were kind when you recruited me and I never had a chance to repay that kindness. Time may be traversed but never mastered: the unexpected happens and in the long run we are all mortal.)

  The Florida house had been scheduled for shutdown. Its environment was growing too unpredictable. But something unexpected happened prior to that closing. As nearly as Ben could deduce from the available clues, the house had been invade
d by forces of the American government.

  The house had possessed some defenses and so did Ann Heath, but perhaps these had been partially dismantled prior to shutdown; in any case, the soldiers of the grim last decades of that century were formidable indeed, with weapons and armor rooted deep into their bodies and nervous systems.

  One of these men must have occupied the house, overpowered Ann, and forced her to reveal some of the secrets of the tunnel. The man had used this information to escape into the past.

  (She must he dead, Ben thought. They must have killed her.) The marauder had invaded Ben's domain without warning, disabled the cybernetics with an electromagnetic pulse, destroyed much of Ben's body, and dumped his corpse in the woodshed. The attack had been quick and successful.

  Then the marauder had opened a tunnel some thirty years long, to a nodal point in New York City, where he had committed the same sort of attack but more thoroughly; another custodian and all his cybernetics were irretrievably destroyed.

  Finally—as a last, shrewd defense—the marauder had disabled the tunnel's controls so that the connection between Belltower and Manhattan was permanently open.

  Catherine said, "Permanently open? Why is that such a great idea?"

  Ben was lost a moment in temporal heuristics, then hit on a simple analogy: "Imagine the nodal points as terminals in a telephone network. Simultaneous connections are impossible. I can call a great number of destinations from one phone— but only one at a time. As long as the connection with Manhattan is open, no other connection can be made."

  "The phone is off the hook," Catherine said, "at both ends."

  "Exactly. He's sealed himself off. And us along with him."

  "But a phone," Catherine said, "if it doesn't work, you can always go knock on the door. Somebody from another terminal somewhere else could have shown up and helped. Better yet, they could warn you. Leave a message in 1962: In seventeen years, watch out for a bad guy."

  Oh dear, Ben thought. "I don't want to get too deeply into fractal logistics, but it doesn't work like that. Look at it from the perspective of the deep future. Our time travelers own a single doorway; its duration governs duration in all the tunnels. From their point of view, Belltower 1979 and Manhattan 1952 disappeared simultaneously. Since that disappearance, approximately ten years have elapsed—here, and in the New York terminus, and in the future. And there are no overlapping destinations. The portal in this house was created in 1964, twenty-five years ago, when its valency point with Manhattan was the year 1937 . . . Are you following any of this?"