Finity

PART THREE I Wonder Who’s Schroedinger Now?

Iphwin had gotten us reservations in a big, modern hotel, one of those places they set up in poor countries so that the well-off can go there without having to meet the poor. We rode there in near-silence. I got the shotgun seat so that Paula could show me how everything worked.

Iphwin told us all, firmly, that we were to rest and eat, discuss as little as we could, neither make nor accept phone calls for any reason, and meet him in a large conference room at 8:00 P.M. sharp. Other than that, he wasn’t about to answer any questions.

Helen and I had been given adjoining rooms with a door between that we could unlock; we promptly did. We ordered room service—happily, Agent Helen Perdita’s tastes in food were very nearly the same as Professor Helen Perdita’s, so at least there was something I knew about this person—then took quick, separate showers. I was about to tumble into bed for a nap, since it was almost an hour till we were to meet downstairs, when there was a knock at the door that connected my room to Helen’s. “I’m naked,” I said.

“Perfect.”

Something about the tone of her voice made me open the door very quickly. When she charged in, I had barely a moment to see that all she was wearing was a pair of satin gloves and a pair of spike heels. She’d gotten hold of two of my neckties, and she rushed in and had me hog-tied behind my back, with my ankles and wrists in one big bundle, before I got done asking her what she was doing. Then she gagged me with a pair of her panties tied on with a stocking, turned me on my face, and said, “You’ve been bad,” and proceeded to spank me till tears ran down my face.

The whole time I was trying to work the gag loose to tell her I didn’t like this kind of thing, that whatever she had done with the Lyle she used to know, I wasn’t him. At least I wanted her to know that she was hurting my buttocks and that I didn’t like it and wanted her to stop. I was twitching and screaming through the gag, unable to breathe, terrified about how far she might go or what she might do to me.

She turned me on my side and I frantically shook my head, trying to tell her that no, I didn’t want or like this, but she gave me a smile that froze my blood, took off one of her shoes, and— very gently, to my surprise—inserted the spike heel in my anus and moved it back and forth. I thought I would throw up; my breath, stopped by her gag, was hot and foul in my lungs, my stomach and chest were heaving, my nose clogged with snot from crying.

She wrapped my penis in one of those satin gloves and stroked me, slowly, a few times. I was more erect than I had ever been in my life.

She flipped me onto my back; that might be a good position for someone who does a great deal of yoga, I suppose, but the pressure on my shoulders, ankles, elbows, wrists, and knees was terrible, and I screamed again, choking now on the tears and mucus dribbling down my throat. My penis, as if it had a mind of its own, kept right on responding to the strokes of the satin gloves, and then she hopped up on the bed and sat on it.

Helen rode me for what seemed forever, and though every joint shrieked with pain, and huge sobs heaved in my chest, at the same time I had never felt a pleasure more intense. She jerked and spasmed three times in big, sloppy orgasms while I struggled and wept; finally, everything gave way—my gut muscles cramped as if I’d been punched in the solar plexus after running ten miles—and I came hard enough to give myself a stomach cramp.

She got off me and got a warm washcloth, then slowly bathed my sore genitals. I wanted her to untie me, but clearly that would only happen on her schedule. Then she rolled me to the side and undid my bonds; I flopped out of the hog-tie like a rag doll, unable to move my arms or legs. She turned me back to her and undid the stocking, then pulled it and the panties out of my mouth. I started to speak but she bent low and kissed me intensely, for a long time.

When she had finished and I lay there, spent and barely able to breathe, with most of my muscles screaming, she said, “You were really a good boy. That’s the best it’s ever been.”

“I’ve never done that...” I said. “Never. I had no idea you were going to ... I don’t play games like that. That wasn’t me.”

“Then whose erection was that?”

I turned on my side, away from her. “I didn’t say I don’t respond to it. It’s nothing I haven’t dreamed about. I said I don’t do it. I don’t want to do things like that.” I crept sideways across the bed, face still turned down toward the covers, hoping to get away from her.

“You’ll be suggesting it to me in a few days, if we’re both alive.”

I hated that snotty confidence in her voice. “I don’t care what you did with any other Lyle. You don’t do that with me. And if you even think it might be me, you ask first.”

She laughed, and it was like Helen in one way, but frightening in another—I didn’t even begin to know this person. “Let me tell you something else, little Lyle. You’re now going to have the sweetest little nap you’ve had in years. I know that your body reacts that way. And as for me—this always seems to sharpen my eye and shorten my reaction time. I’ll be fast, precise, and relaxed for the next few days. Whatever you may think at the moment, my little crybaby tramp, we’re both better off. And you enjoyed it whether you admit or not, you little whore.”

She squeezed my testicles, hard, and I nearly vomited as I yelped in pain. Laughing as if it were Christmas, she stretched out beside me.

Strangely enough—how could I sleep next to someone who so terrified me?—it wasn’t long before I fell sound asleep. When she shook me awake, we had just fifteen minutes to get down to the meeting. I didn’t look at her and I asked her to leave the room while I dressed. She laughed at me again, and I really didn’t like the sound of it this time. It was even more frightening, and even less Helen.

Iphwin began his talk obliquely; he said, “I have spent a very long time thinking about how I was going to present this to all of you, and I’m not altogether sure, even now, that I have picked the right way to do it. I know you must be curious about who I am, how I came to know the things I am going to explain to you, and how and why I have undertaken the project that I am asking you all to join—but I am going to deliberately not gratify your curiosity for the moment, because my explanation will make a great deal more sense if I first give you some basis for understanding it. I hope that I am making myself completely obscure?”

“You are,” I said, since no one else spoke.

“Well, good, then my sense of how the human mind responds is not completely wrong. I hope I can make matters clearer, later, but for right now it is probably appropriate that they be obscure. To begin with, then—your surmises, Lyle, Helen, and some of you others, about the Many Worlds Interpretation and some of the other questions, have been largely correct. People, information, and objects did indeed begin, a few decades ago, to cross over between different worlds, as you call them—or timelines, or histories, or event sequences, depending on whose terms you prefer to use—and this does account for discrepancies in your memories, for the occasional outright violations of causality you have noticed, and even for the new cultural norm of people avoiding any sort of discussion of the past, even of their own personal past.

“Has any of you figured out when these things happen, or what triggers them?”

There was a long silence, and Iphwin said, “You couldn’t be expected to, of course—for one thing, the experience itself is sometimes mildly disorienting, particularly if you’re crossing between event sequences which are extremely different, as has happened to several of you in the course of your lives. Well, I can now fill you in—or I suppose if I can’t, I’m about to find out.

“People cross over when they talk on the phone, when they get on-line, and when they ride in a robot-piloted vehicle.”

I felt like I had just gotten an electric shock right up my spine; suddenly everything was clear. “That’s why!” I said. “They’re all driven by quantum computing devices!”

Everyone turned and stared and I remembered that I was the only person with any physics background in the room. “Er—” I said.

“You’re exactly right, Lyle,” Iphwin said, “that’s what’s going on. And the odd part is, that isn’t really a problem. It’s merely the reason why the real problem has gone undetected till now. But I’m getting ahead of myself—perhaps I should just launch in, and if we can get the occasional assist from Professors Peripart and Perdita, we can put the whole story together quickly.”

Iphwin’s lecture and the questions after it ran till midnight; he provided us with plates of sandwiches, pastries, fruit, coffee, tea, and juice, and gave us a bathroom break punctually on every hour, so we endured it well enough physically, but some of us had hoarse voices from arguing by the end, and almost all of us had brains that hurt. But he kept producing evidence, and what he told us fit the facts. Eventually we bought it, perhaps because it was such a relief to feel like we understood what was going on.

There were indeed many worlds—in fact there was every possible world. Perpendicular to time, and to our familiar spatial dimensions, there were five spacelike dimensions Iphwin called “possibility,” and each event sequence had a unique five-dimensional address within those dimensions. “Suppose there was just one thing in the universe, and all it could do was to be somewhere—and there was just one spatial dimension,” Iphwin said, trying to get it across to our less mathematical members. “The one spatial dimension would be a line, right? Imagine it as a road, if you want. The one object is a car, and every time it passes through any given place, it’s an event. Now, you could make a picture of the universe as a graph, with the horizontal being the position on the road, and the vertical being the time. On that graph a vertical line would mean the car just stayed in one place, and the more horizontal the line got, the faster the car would be moving. A big curve like the letter S would be somebody driving back and forth. Every point on that line would be an event. Does that make sense so far?”

“It’s been a long time since I had to take algebra,” the Colonel grumbled.

“I can promise you that they haven’t improved it any, either,” Terri said. “All right, so then if you have one dimension of possibility, it’s like stacking all the possible graphs there can be, one on top of the other, with the most similar ones closest. Right?”

Iphwin seemed startled. “You have talent.”

“I spend all my time in school. I’m used to lectures. And besides, you said a world or a timeline could be called an ‘event sequence,’ right? Well, then obviously a line of events, like what you’re describing on the graph, is an event sequence. And time only runs one way, and you said there’s just one car on the road, so if there was just one world it would have just one line. If there are many worlds, then you have one graph for every possible way a car could go back and forth on the road. That’s all.”

“And it’s right,” Iphwin said. “Those of you who are confused should consult with Terri from now on.”

“And those of you who want to be confused can consult with me,” Paula Rey said. “So the whole point of the graphs and the road and so forth is that it’s a very simplified version? In the imaginary world there’s one object, one dimension of space, one dimension of time, and one dimension of possibility, right? And in our real world you’re saying we have some huge number of objects, three dimensions of space, one of time, and five of possibility?”

“That’s it exactly. You’re not as confused as you think you are. It’s just that what I’m telling you is pretty big. Now, one of the implications of this is that in the dimensions of possibility there can be an infinite number of worlds next door. A point can have an infinite number of neighboring points, and that’s in two dimensions; a line can have an infinite number of neighboring lines, in three; and so forth. By extension, an event, which is a four-dimensional thing, can have an infinite number of immediate neighbors in the five dimensions of possibility. And those are just the ones at zero distance.

“Now it turns out that if you cross over into another event sequence, you’re more likely to cross over to a nearby one than to a far one. In fact, every second that you’re on the phone, you’re bouncing from one world to another constantly. It’s just that most of the time, you bounce between worlds that are so similar that you can’t tell the difference. For example, maybe in one world you have a few more atoms of calcium in one of your teeth—or maybe the buttons on your clothes are six microns larger. Or maybe you bounce to a world where all the way across town, a man is washing his car instead of reading the paper.

“But every so often you take a bigger bounce, and you’re in a world where your history is noticeably different. That’s what happened, for example, to Helen Perdita when she was a teenager, or to Paula and Jesús more recently.”

“Why should it happen when we’re on the phone?” Roger said. “Why not while we’re bathing or flossing our teeth or asleep? And didn’t you say it also happens while we’re on-line or while we’re in a robot-driven vehicle?”

“All of the above and a few others,” Iphwin agreed. “Perhaps Lyle has gotten it all figured out now, since he’s had time? He’s more experienced at lecturing than I am, and since the idea is new to him, maybe he can explain it more clearly than I can—the idea is at the core of my being, you might say, so I’m apt to assume too much when I explain it.”

I harrumphed and collected my thoughts. I began by telling them about Schrödinger’s cat, and the whole problem of how to interpret a distribution of quantum states when you project it upward into the macro world. Then I found myself explaining something that tends to make people nervous, and therefore is rarely publicized by the big communications companies.

“Maybe seventy or eighty years ago,” I explained, “people doing brain research got interested in the problem of how the brain could possibly be storing as much sheer raw information as it seemed to. Once they started to get some idea of how things were coded into individual brain cells—basically as linked sets of physical impressions—it just didn’t seem like there could be enough room in the human head for all of that. Since we didn’t have room for the brains to do it with, how were we remembering so much?

“Well, the answer turned out to be, we weren’t. You remember someone’s face as, maybe, an impression of one eyebrow, half the lower lip, part of the nose, and an eye. When you recall their face later, what your brain does—faster than anyone could sense in real time—is to reconstruct the picture, filling in all the details. It’s easy for the brain to do because faces are symmetrical, some kinds of features tend to go with each other, and so forth. The mind has a fast little interpreter that fills in the rest of the picture.”

“That’s why most pro actors can get up on a part fast, in terms of knowing roughly what they do when,” Kelly said, “but getting from knowing your part to knowing exact words is a pain in the ass that takes forever. You can learn a few markers almost instantly, but to get the whole thing perfect you’ve got to have many more markers, and then get the feel of the text, so that what you construct between the markers is always right.”

“Exactly. Well, that was kind of interesting, as a piece of brain research, and it helped to explain little things like the way you’ll sometimes mistake a stranger for an old friend you haven’t seen in a while, or the way people will begin to remember something different from what happened if you repeat a story to them often enough—they start to fill in bridging material that includes some of what you tell them. But the most important application came later, in communications. It was a solution to the bandwidth problem.”

Among questions and interruptions, I sketched out the basic concepts for them. Imagine an old-fashioned Morse code transmitter, sending dots and dashes; it has a bandwidth of one. That is, either the wire has current flowing through it, or it doesn’t. Now, since no Morse signal has more than four dots or dashes, theoretically if you had four wires, you could send each character all at once, instead of sequentially, and send four times as fast. That’s a bandwidth of four. The amount of information that can pass a given point in a given time is speed times bandwidth—and since by the turn of the twenty-first century, bandwidths were running into millions and speeds to megahertz, trillions of bits per second were traveling through each junction in the system.

It still wasn’t fast enough for some purposes, and most especially not for one commercially very important one. The human senses as a whole have a bandwidth that runs into many trillions, and you need to be able to simulate all the senses all at once in real time to produce effective virtual reality. And you want to produce that really effective virtual reality because human beings seem to have a nearly unlimited demand for being made happy and taken care of all the time—we’re all big babies on some level, I suppose—and anyone who can deliver that cheaply enough can probably collect the whole wealth of the human race eventually; even now there are people, especially people born rich in some of the advanced nations in some of the world lines, who spend more years hooked up than not. So one way or another, they were going to get that bandwidth, or figure out a way to put a great deal more through the bandwidth they had.

As it turns out, you can simulate reality fast enough to do vivid VR, but getting signal into and out of the brain requires enormous bandwidth, and thus though a VR simulator could deliver enough signal to produce a vivid reality for one person or a few people, a single long-distance VR call would theoretically have required more bandwidth than the whole United States had used for radio, phone, and telegraph to get through the Second World War. Though there was an enormous market for VR worlds that could be shared as real, living, breathing experiences, to provide for that market would seem to require the construction of enormous facilities to provide enough bandwidth for all that signals traffic.

There was another enormous demand for bandwidth lurking in the wings too. Self-piloting vehicles would work best if every car on the road could share information with every other car. You wanted a car that could think and look fast enough to figure out that a ball rolling into the street was apt to be pursued by a child, or to dodge around—and alert every other car to—a board with nails lying on the pavement. Once again, bandwidth needed was just much, much bigger than the bandwidth that could even conceivably be made available.

Computer speed depends in part upon internal bandwidth— because the size of the chunks of data moving around inside the computer determines how fast the computer can rearrange information, and therefore “think.” Since VR communication had to move through the computer anyway, putting it through a faster system was highly desirable, and the fastest systems of all, by the mid-twenty-first century, were quantum computers—systems that took advantage of the peculiarity of quantum physics that a single object could behave as if it were in a distribution of several mutually exclusive states all at once. In effect, you could solve the problem of the dead cat and the problem of the live cat simultaneously, and each bit in the computer’s memory and each operation in its registers could be in parallel with itself; a single machine could be made to act like many thousands all at once, with a tremendous gain in speed.

But massively parallel processing had another use—it was exactly how computer engineers had been able to simulate many human brain functions. The ability to construct a face for recognition, or fill in the lacunae in a partial text, or smooth out a partially degraded hologram from fragments required the massive and fast parallelism that only the quantum computer could provide. The quantum computer, then, made real-time VR communication possible, for it made it possible to transmit a small fraction of the needed information for the simulation, and from that information to construct a full simulation at the other end.

But the uncertainty principle limited the user’s control of the information; you couldn’t know which state any of the quantum processors was “really” in without preventing the parallel processing you needed. If you bought into the Copenhagen Interpretation, this was no problem; you simply treated it as a computational trick that allowed you to get away with sending less information than the other side received. Likewise, in the Aphysical Interpretation, the problem was no problem—it was as if you had two ponds, with a stick in each one, and the two sticks connected by a string: a wave in one would make a wave in the other, and multiple and complex wave patterns went through because the stick could move in multiple and complex ways.

But in the Many Worlds Interpretation, what you were doing was solving the problem by using all of the neighboring worlds plus your own—and the uncertainty principle would not let you know which answer was going to which address. Those who thought about it at all, in those terms—my friends and I, in grad school, had often argued about it over beer—had always assumed that the solution must be that in a quantum computer network, there must be a great many “cosmic wrong numbers”—i.e. messages that went to the wrong universe. That always led us to argue that we had found a reason the Many Worlds Interpretation could not be the right one—because the uncertainty principle, applied to the addressing problem, seemed to say that you couldn’t know whether or not a number was wrong, and thus all those “wrong numbers” would violate it.

We had never considered that Nature might solve the problem by not allowing anyone on the receiving end of a message to know what universe he was in. And yet that solution now seemed exactly the sort of thing you might expect of Nature in her better moods. Whoever was receiving the message would exist in a suspended state, like Schrödinger’s cat, for as long as they were on the line; unlike the cat, they would not be half alive and half dead, but fractionally in many different worlds. Hanging up or briefly disconnecting—and the line-sharing protocols in any modern network guaranteed brief disconnects many times per second— was exactly the equivalent of opening the box and collapsing the probability distribution onto a singular state—living or dead for the cat, some universe or other for you.

Once the wide-band quantum network had come into use for VR, everything else had been piggybacked onto it, because it had so much room for everything else—transportation signals, fax, television, telephone, and all the rest. Whenever you went on-line in the quantum communication system, you oscillated through many of the possible system states, many times per second. This was true whether you were a person, a bale of hay, or an e-mail message.

“So,” I concluded, at the end of it all, four sandwiches, six cups of coffee, and too many arguments and diagrams to count later, “basically we’ve been reshuffling all the worlds at a faster and faster rate, and as each big family of event sequences gets VR and quantum computing, the number that we can interchange with has increased polyfold. By now nobody is in the world they began in. Mostly the worlds are enough alike so that people adapt, though I’m sure there are more street crazies and mental patients than there used to be in most worlds, and many of them probably spend all of their time trying to tell anyone who will listen that something is terribly wrong.”

Iphwin nodded, and said, “And that brings me to who or what I am. As systems grow, as you know we have to decentralize control more and more to keep them functioning. That ends up implying, among other things, that instead of a central administration governing everything, you get by with roving pieces of software that just look for whatever isn’t working as it should. That is, the system administration stops looking like a police and court system, and starts to look more and more like an immune system. Systems administration becomes a matter of operating a population of cyberphages—benign viruses that keep users from doing things that damage the system. It’s easier and cheaper than keeping everything tied to a central program that has to know everything.

“A few years ago, one cyberphage began to notice that there was a common problem in every one of the parallel universes, all at once. And that problem was the disappearance of the billions of nodes found in the United States, American Reich, Purified Christian Commonwealth—whatever you called that piece of land between San Diego and the St. Lawrence or Puget Sound and the Everglades. Once it noticed that there was no traffic at all, for several seconds, it began to track this—only to discover no traffic for periods of months or years, across all the event sequences to which it had any access—that is, across an enormous number of worlds.

“It looked very much to the cyberphage as if some large number of people and machines had either been cut off from the net, or left voluntarily, or something—but whatever it was, it wasn’t good for the network. The cyberphage thought about this for a very long time, the way an entity that lives on the net between all the universes can think—quickly and thoroughly—and decided that since no information seemed to be emanating from that country—not a transaction record, a phone call, a bill, or a bit of mail of any kind—the only solution would be to go have a look for itself.

“That took some effort,” Iphwin said. “About twenty-five years, but of course a cyberphage is immortal, and there’s the advantage of being able to operate across billions of event sequences all at once. The hard part was the need to get a physical body in which to walk around, if I was going to go and take a look myself.”

There was a long pause as we all digested that, and then, very tentatively, Jesús said, “Sir, am I to take it that you want us to believe that you are that cyberphage?”

“Well, perhaps a better term would be that I am its avatar. The cyberphage not only still exists, it runs ConTech; one reason you heard the sort of rumors you did about the company was that its only real purpose was to accumulate money and power, as a means to the more important end of getting an embodied form of myself into a physical world, with an appropriate team of people so that we could go and have a look at what’s become of America. That required a million man-years of bioengineering, as you might guess, and a great deal of tinkering with the brain-body interface, but... here I stand. If you were to lift up the flap in the back of my head, you’d find a billion-nanopin interface for reporting back to Iphwin Prime—that’s what I call my progenitor—and I was in a tank till I was physically adult, but other than that, I guess you’d have to say I’m as human as you. And just as bewildered.”

Helen had been sitting with her arms folded, sometimes glaring at Iphwin and sometimes glaring at me. Now, finally, she spoke. “And all the manipulations?”

“I didn’t have any way,” Iphwin explained, “to control who or what went to which world. Nobody has that ability—the very thing that lets you shift worlds is the uncertainty with which it happens. But while I can’t control the shuffle, I can control how fast it’s dealt, and I can look at every hand. What I did was that I recruited teams of people that I thought might be able to solve the problem, and then I kept shifting them between event sequences till I had some version of all of the critical people together in one event sequence, or to be more precise about it, until I knew it was very likely that I had all of you together.

“Then to join you, I made that voice phone call, and did it in a system that hung up and reconnected at terahertz frequencies. It kept checking against other stuff you were doing, till I got it narrowed down as much as could be managed; then in the last few seconds I just oscillated until the system found you. There was an uncertainty trade-off, as always—I have some big gaps in my memory and neither I nor the cyberphage knows exactly which Iphwin I am. Millions of Iphwins must have shuffled right out of reality to get me here.”

“But you didn’t feel them go,” Helen said.

“Does that matter?” Iphwin asked, puzzled.

“You bet it does,” she said. “I’m just wondering if by any chance you’ve noticed that most of us gave up our old lives to be here, and you never asked us if we wanted to.”

Iphwin nodded. “That’s true. And if you really insist, you can leave now. I’m hoping you’ll stay for a variety of reasons— that is, both, I have a variety of reasons to hope you will stay, and there are a variety of reasons why any one of you might. I hope you will at least hear me out.”

“I’ll do that much,” Helen said. “But right now I’m not very inclined to believe you. You’re a ghost personality, one created by a machine to embody itself. You didn’t give up relatives, friends, lovers, any of that. You were created mostly to be thrown away—”

“All human beings, ultimately, are thrown away,” Iphwin pointed out. “Most for no reason, since the universe has none, and they simply go away, used up, never to return. You were picked because, first of all, you were a likely bunch of people to care about what had happened to America. Most people don’t or wouldn’t, you know. Why should they? Whatever its importance in the world might once have been, it doesn’t have it any longer. The cultural role has been taken over by the expat culture, the physical economy of the world seems to have disconnected without anyone noticing, and in most of the event sequences there’s no active military balance-of-power problem. America seems to have faded everywhere, long before it disappeared completely. Fortunately for this project, there still are a very few people who are still concerned about it, and you all are among them.

“Then there’s the matter of skill at abduction. The cyber-phage of which I am an avatar, being a machine, may have overrated the importance of abduction, since so far no one has found a good way to provide machines with the skill. But I’m as human as you are—”

“So you say,” Helen said, making her contempt clear.

“I have a personality physically embodied in flesh made according to human DNA, and that’s good enough,” Iphwin said, firmly. His face got red as he said it, and I could hear the stress and anger in his voice.

There was a very long, awkward pause, before Iphwin finally resumed. “To summarize, Lyle Peripart is an authority on the mathematics of abduction. Helen Perdita’s discipline involves solving practical problems in abductive reasoning, plus many versions of her are skilled in operations in dangerous areas, plus of course she’s personally loyal to Lyle, which may be valuable in a tight spot. Then I needed someone who could handle command and who was closely linked to Lyle, hence your presence, Colonel. I got you your two old executive officers, with a bonus that I needed a couple of investigating detectives—which is why I got not only Esmé Sanderson, but also Jesús Picardin.”

After a minute, Kelly said, “You haven’t explained why Terri and I were brought into this, and you went to some extra effort to get us.”

Iphwin nodded. “I had no creative artists, and that’s a whole other style of abduction. And I needed someone who practiced the harder creative arts, the ones where you accommodate to the world around you rather than the ones where you just dump out whatever you’re feeling inside and then shape it for others. That kind of talent for making the piece that fits with the other pieces, that ability to fit in, the thing actors call rapport or chemistry, was a kind of creativity I wanted to make sure of, and that’s the kind that actors are good at. And then, for Terri...” he sighed. “Ethically I’m on shaky ground here, but, well, she was the only member of that VR chat room that I didn’t already have coming, and somehow that felt like a mistake. She’s physically healthy and bright, and I would guess quite adaptable.”

“And she’s right here listening to you, so you can stop talking about her in the third person,” Terri said, flushing with rage.

Iphwin went right on. “Also, Terri, like most smart teenagers, you don’t have an excessive respect for authority. My feeling is that whatever we find when we get north of the border, it’s not going to be so much finding it that’s a problem—it’s going to be understanding whatever it is we’ve found. The erasure is so complete—and so perfectly confined to the old 48 contiguous states—that it just doesn’t seem like it could be any kind of natural phenomenon. Nor does it seem like anything anyone could do on purpose. Which seems to cover all the reasonable and comprehensible possibilities, and so chances are that what we are looking for is unreasonable and incomprehensible. Hence my urge to throw a few wild cards in—purely a hunch.”

“You’re telling me that I’ve left my entire world behind because you had a hunch?” Terri demanded. Her bony shoulders were high up, and her arms were folded tightly.

“It would appear so, yes.”

“And you just decided to use all our lives?”

Iphwin seemed mildly exasperated. He was at least human enough so that he was bothered to be confronted with something he had not thought of before; few human beings really like the unexpected. “What I am doing is no different from what a president or king does when he starts a war, or from what a corporation president does when he orders a new product into production. I am changing billions or trillions of people’s lives drastically without their consent. The only difference here is that ten of you are having the opportunity to confront me about it. If the confrontation makes you feel better, I suppose that’s all right. But it doesn’t make any other difference, and I wish we could concentrate on more basic issues.”

“Not having our lives torn up is about as basic an issue as there is,” Helen said, “and Terri is absolutely right to be upset. If you want our assent, you’re going to have to offer us something better than just making us rich, or give us a reason better than just because you happened to need it and thought we would make a good team. Why should we conduct your investigation for you? Show us why we shouldn’t all walk out of here and start dialing the phone at random, until we manage to find somewhere close enough to home so that we’ll want to stay.”

Iphwin sighed and spread his hands. “I suppose in some sense that my inability to anticipate this does demonstrate the difference between human and machine. But I had thought that since in fact you have been bouncing from one world to another every time you use the phone, or the net, or ride in a guided vehicle, that you would realize that you aren’t being ripped from your homes—that in fact you’ve never been home for many years, and you were never going home.”

Helen folded her arms and stood her ground in a way very like the Helen I remembered. “Well, we only just found out we’ve been crossing from world to world a few minutes ago, you idiot. We’re still getting used to that idea. And now we learn that you’ve been deliberately causing part of it. How do you expect us to feel?”

“I have great difficulty expecting anyone to feel anything,” Iphwin pointed out. “And I am forced to admit that even in this body I don’t feel things very much myself—I suppose that’s a matter of the body not having received any emotional conditioning when it was younger. I suppose you might say I feel more like I’m wearing it than as if I am it. But I do notice that the glandular systems have a great deal of lag time—that emotions often persist long after their cause is removed. Is that the sort of problem you’re talking about?”

“It might be, but it’s a very lengthy and not-human way of expressing it,” Helen said, grudgingly. “The point is, you have to allow us some time for emotional adjustment. We’re all new to what’s going on, it’s frightening, and you are at that core of what is frightening about it. And if I may add without offending you, Terri—Terri’s godawful young to discover that you’ve separated her from her parents, possibly forever, and I don’t think your mission, however important you may think it is, is going to justify that sort of thing in any of our minds.

“I suppose what you are asking for might be logical, or reasonable, or whatever, but it isn’t even remotely sensible in emotional terms. Now, if you really want our trust, you’re going to have to give us at least some evidence that there is a good reason for us to give it to you, rather than just walk out of here. And don’t try to make it sound like a geometry proof while you’re doing it.”

Iphwin sat down at the edge of the low stage, balling his hands into tight fists, clearly frustrated. “I don’t have a good answer for you,” he said, finally. “There is something strange about the disappearance of a whole nation from the earth, from history, from everything, and the unknown forces that prevent our knowing anything about what happened. And maybe we don’t see it because we are too close, but I think there is also something strange about the way that very few people have noticed or are reacting to it.

“What I want to do is to resolve that question. The part of me that is a product of so many years as a machine intelligence really has no motivations other than curiosity, given that sex and death are beyond it. And the part of my mind that has grown into this body is just a few years old and has had no childhood, no imprinted memories to speak of, no distinctiveness from any other human body. In the circumstances, I made my best guess. I looked for people who had the knack of abduction, and who I thought might still have enough love for the idea of America. And I did what was necessary to get them together into a single event sequence so that we can work. That was the best solution I could think of. If it has not worked, then either you, with your abductive gifts, must think of a better way to solve it, or it will have to be left unsolved.”

There was a very long, awkward silence, before Roger Sykes stretched, fluffed out his white hair, and stood up, propping himself with his cane. He said, “Uh, well. You know, I’m bored stiff. And I was born into the regiment; my dad told me about being a boy in the States but I never went there myself. And I’m an old guy, if I die, you know, no big deal, I was planning to do that sooner or later anyway. So ... I guess I’ll go and take a look.”

Iphwin looked up with hope in his eyes. “Thank you.”

“You’re welcome. Long as I’m here, and so forth. But you really do need to develop your skills at asking people instead of manipulating them.”

“Yes, I suppose I do.”

After a moment, Esmé got up and moved next to Sykes. She was even bigger than my first impression had said she was—she absolutely towered over the older man. “Colonel, I’d be pleased to go with you. There’s just not that much going on in my life and I don’t have anything I’d rather do. And it would be kind of interesting to find out what’s happened to America.”

“And if Esmé is going, I better go too,” Paula said, “to keep you two out of trouble.”

Jesús Picardin spoke next and said, “You know, I have been very bored with my work, and I would have to say that there could hardly be a more interesting kind of case for a detective than having an entire nation go missing. And probably I’d never get back home anyway, and frankly this just sounds much more interesting than anything else I could be doing.”

“This is starting to seem like a lot of peer pressure,” Kelly complained. “All right, you want to go, so go. There’s not necessarily a good reason for the rest of us to go, is there?”

“Not necessarily, but let’s see what the options are,” Helen said grudgingly. “I don’t like to admit it but I think Iphwin here has us over a barrel. If I understand all this Schrödinger stuff, we can wander around for the rest of our lives picking up phones and then hanging up, and going for rides in robot vehicles, and logging on and off the net—but the odds of getting back to a world that we recognize are pretty small. And anyway, all we’d be doing is displacing some other version of ourselves, bumping someone else into our mess. For the time being I suppose we’re pretty much stuck in this world—and what world is this, anyway?”

“Well, you’ll have to take my word for it,” Iphwin said. “Because if you try to check by net or phone you’ll be leaving suddenly. But this is one of a relatively small family of event sequences where there was a coup in the United States in 1972, over the withdrawal from a war in Vietnam—Indochina to some of you. Military junta took over to restore order and honor, which basically meant to suppress political expression at home and use nuclear weapons to win in Vietnam. They got into an arms race with Communist Germany, which was the other big power in that event sequence, and eventually bankrupted the Germans. Then they stayed in power indefinitely, getting less and less repressive with time; they enforced a huge, complicated array of rules governing every aspect of daily behavior to make the country look as much as possible like it had in the 1950s of that event sequence, which was pretty dull and conformist. Not the best of worlds, not the worst. The rest of the world is mostly in small nations; devolution went pretty far. There are hundreds of prosperous small states—imagine a world full of Switzerlands. You could live here pretty nicely.”

“But good luck explaining why you wouldn’t talk on a phone or use a self-driving vehicle, eh?” Kelly said. “I guess I’d have to hope there was an American Theater in Ciudad de Mexico, or maybe start one. I don’t have too many good alternatives, since all I’ve got is travelers’ Spanish. Can you tell me what happens if I do go along?”

“If I knew what would happen, no one would have to go, and I’d never have disturbed any of you,” Iphwin pointed out. “And I do have considerable resources, so if you truly don’t want to go on the expedition, I can find you a job in my organization, probably in some office where you won’t have to expose yourself to accidental transfer. If that is what you would genuinely prefer.”

“Aren’t you worried that we’ll all take that offer?” Helen asked.

“I am, now that you mention it. But it seems like the decent thing to do, given the things you have pointed out about my having so disrupted your lives. And I already have some volunteers, anyway. As you point out, I’m really not good at working with people. This is the best I can do while improvising.”

As I listened to all the arguments, I had been thinking about my own position. This Helen didn’t much resemble the quiet historian that I liked; and if I couldn’t find the exact one I thought I knew... well, really a composite, since I must have interacted with thousands of very slightly different Helens, each of whom knew thousands of versions of me ... all the same, I could find a more comfortable connection than this one. The odds even seemed reasonably good if I just started making a lot of phone calls.

On the other hand, what had happened to the United States of America, and how had I—who had been raised as an expat patriot, proud of my heritage—never even noticed that the country itself was gone? Clearly the net extending across all of the worlds had a great deal of editing ability, and both it and the human cultures that depended on it for communication had evolved an immense and sophisticated system for suppressing excessive questions about the inconsistencies that were generated, so it was possible for whole families and complexes of facts to disappear or at least become unspoken.

But a whole nation?

I had to admit, it was an interesting problem. And if I started working that phone, I might or might not ever know the answer. Besides, I could just as easily work the phone trick, to find a more compatible Helen, after the expedition—assuming I survived—as before it.

For that matter, if there was going to be shooting, this Helen had advantages.

The room had gotten very quiet as everyone who hadn’t committed to the expedition tried to figure out what was best for them. With an effort I drew a breath and said, “Well, then, I guess I’ll go. No reasons I care to talk about.”

Helen seemed very startled, and then said, “What the hell. Me too.”

“And me,” Ulrike said. “It makes more sense than trying to do anything else; at least this might lead to something, and everything else just leads to being stranded or picking up a phone and trying for a new world at random.”

Kelly and Terri looked around the room as if we had all betrayed them, which I guess in a sense we had. With a sigh, Terri said, “You all are the only people I know in this world, you know? If you all go, I kind of have to go. ’Cause I’d rather not lose the only people I have, and I don’t have any real strong reason to not go, except maybe that I’m kind of afraid—which is a bad reason for not doing anything, I think. Am I making sense? Anyway, I guess, me too, but I’m not happy.” She looked down into her lap where her hands curled and twisted against each other.

Kelly seemed to be almost in tears, and I don’t suppose I could blame her. “I feel so forced into this.”

Helen grunted. “You should. That’s what’s happening, you know, no matter how rational it is to do what you’re doing. It’s perfectly rational to give a man with a gun your wallet, and it’s your decision to give it to him, but that doesn’t mean you aren’t forced. You might decide to have your leg amputated if it was badly enough injured and infected, but that doesn’t make it a free choice.”

Kelly swallowed hard and brushed tears away from her blue eyes, smearing her mascara and making her look messy. “Well, it’s a pretty bad deal, but I do think you’re right—it’s the only one I’ve got going. I guess what I’d better do is come along. Am I required to have a positive attitude?”

“Not at all,” Iphwin said. “I don’t.”

The vehicle that the ten of us moved into the next day was an ugly old museum-piece of military hardware, but with Iphwin’s resources applied to getting it, it also happened to be the perfect thing for the job.

It was a hideous old American Army Model 2018 Squad Transporter, which Roger, Esmé, and Paula all groaned at the sight of. They informed us that it was most commonly known as an “esty” and that “although officially it was a device whose whole purpose was to carry up to a dozen people into harm’s way in a way that protected them and allowed them to do some harming back, its actual role was to maximize human discomfort as part of a sadistic and pointless research experiment,” as Roger Sykes put it.

This particular esty had apparently been used as a bus by someone with an odd idea of what colors went together, so it had had to be repainted, but the lines and cracks of previous paint jobs showed through the new charcoal-gray paint everywhere. Windows were small and thick with a self-closing gunport beneath each one; the windshield was in two layers spaced about a handwidth apart. Heavy flat rectangular boxes of metal, filled with something to stop projectiles, were placed all over it in a not-too-symmetric way, hanging all around the engine compartment, off the doors and side panels, and so forth. The roof had an unlikely number of roll bars, some of the metal boxes, and just enough thickness to make me pretty sure it was armored all over. The one real weak spot was the rear window, which had clearly been replaced, long ago, with ordinary glass. Roger and Paula fretted about it a little, and rather upset the rest of us with the concern, but since we had no way, in any timely manner, to replace the rear window with any real armored glass, the upset was all they accomplished.

Naturally it was hand-steered and without any sort of net-based navigation.

“Must have spent a few years in the American Army,” Paula commented as she ran a series of checkouts and I looked over her shoulder, “and then come to Mexico to be modified for use in one of the many dustups down here, and then gone civilian, oh, I don’t know, twenty years ago, probably in the early ’40s. After all these years, it’s finally going home—even if it has to go armed.”

Paula was driving and since I was the current apprentice driver, I sat next to her. The Colonel sat in the middle seat to the right, behind me, so that he could see as much as possible from a protected position, since he was our de facto commander in the event of trouble, and also so he could cover one gunport. Esmé sat on the other side. Jesús and Helen were at the rear corners, able to use either side or rear gunports, and the front was covered by the remote-sighted machine gun on the roof, which either Paula or I could operate from controls on the dash, sighting through a small video screen between us. We weren’t a tank, but we were likely to be more heavily armed than any casual opponents, and that was the real idea—we didn’t want any trouble from the bandits who had come to infest the north in recent decades, so we were trying to be too tough a nut for them to crack. If there were an “other side” out there, we knew nothing of its resources but would have to guess that they were far, far more than this little armed bus could possibly handle.

There were four people, besides me, who weren’t arms-proficient—Terri, Kelly, Ulrike, and Iphwin—and they were allowed to float more or less freely with the understanding that in the event of any trouble, they would get down on the floor in the middle and stay there.

“What kind of range does this thing have on a tank of fuel?” I asked Paula.

“It has Telkes batteries,” she said. “It’s all electric.” Seeing my blank look, she added, “Telkes batteries are nuclear batteries, and they are supposed to be good for a million miles, and there’s only 350,000 in the mileage record on the central computer. Which doesn’t appear to have been tampered with, unlike the odometer.”

We were pulling slowly out of our spot in the parking lot of the expensive hotel in Mexico City, and Paula turned around to holler, “Anyone who is about to suddenly remember something that belongs in the baggage locker is welcome to do it now.”

“Everything’s down there,” Terri said. “Nobody’s got anything bigger than a purse up here.”

“Just making sure,” Paula said. “In the event of an accident I want to be hit by a nice warm soft human body, not by a suitcase. All right, pulling out, heading north, and if you can sleep where you are, do it, because today is a good day for resting up; we don’t really hit bandit country till tomorrow afternoon.”

The first day’s drive was as uneventful as she said; we cruised along a potholed but perfectly adequate road, and I got to drive more than half of it. Getting used to pointing the wheels with the steering wheel was easier than it seemed, and the load-balancer that fed power to the electric motors on the wheels worked pretty smoothly so that the response of the esty to the steering wheel was consistent. The thing I had thought was the accelerator was more properly speaking a speed pedal, the device that set the velocistat—i.e. it was the device you used to tell the car how fast you wanted it to go, rather than to make it go faster or slower. Push the pedal twice as far down and the vehicle adjusted its speed to go twice as fast regardless of what slope you might be on. The biggest problem, and the object of plenty of backseat-driver humor, was the brakes.

“The main brakes are recovery brakes,” Paula explained. “Basically when you apply the brake, a rotor on the wheel generates an electric current that sets up a field that opposes its own motion. It uses the car’s own energy against its motion—the faster you’re going, the harder the brake works, and if the tire locks, the brake lets go right away. Skidproof and stops you in the minimum possible distance—or rather it stops the esty. If you’re not wearing your seat belt, it might not stop you—or rather it will, but it will use the windshield instead of the belt.”

“Very comforting,” I said. “And I’ll try to keep it in mind.”

“Road’s nearly empty,” Paula said, turning and looking around, “and the whole group is belted in. You might as well practice. Give it a shot—try to brake smoothly.”

I pushed down as slowly as I could on the brake, and felt the drag slowing us down, but then the brakes seemed to grab and the truck jerked a couple of times.

“You have to lose that habit of pushing harder and harder on the brake,” she said.

“He sure does,” Ulrike said. “Are you really learning to drive this thing, Lyle?”

It was a stupid question in a tone that I think was intended to be flattering, so I said, “No, I’m not learning a thing and I haven’t a clue how to do this. Paula put me in this seat because she’s trying to kill us all.”

Ulrike managed to be perfectly quiet while still letting me know that she was wounded and that I had better apologize. I was really wondering what my other selves, in whatever other worlds, had been thinking, in marrying her. At least I could make a good guess about what they had been thinking in divorcing her.

The morning and then the afternoon rattled on, bouncing our way along the road that became more and more potholed, more and more badly marked, and more and more deserted, until finally we reached the mostly deserted fortified town of Torreón, the northernmost garrison on Federal Highway 49. Most of the old town was block after block of charred and bulldozed ruins, because as the city had lost most of its population the abandoned buildings had become cover for bandits, rebels, and other marauders, and so the local commandants had gradually smashed down everything outside the fences and walls of the central compound, which embraced the former town hall and church, and surrounded, for a radius of only about a block, what had once been the zócalo.

Iphwin had set us up with one whole floor of the one surviving large hotel in the compound, and had managed enough bribes to the garrison commander to get us electricity and hot water for the night. “This is it,” he said. “Last comforts, that we know about, anyway. Enjoy it while you can.”

A day of being shaken around, as we had been in the truck, takes a lot out of you, and everyone elected to eat in our rooms and get to bed early. Helen joined me in my room, just for company, and after the dinner had been delivered, we ate quietly for a while. “Not bad for where we are,” I ventured, at last.

“The food? Decent, I guess. Though I can see why they shred the beef—there’s probably not a knife that can even scratch the local stuff. But somebody knew his way around the kitchen, and that’s got to be pretty rare in a place this remote.”

“Isn’t that strange,” I said, having been hit by the thought. “I’ve never really been anywhere remote in my life before, you know. And I bet neither have you.”

After we’d finished eating, Helen said, “All right, I guess you really did think it was obvious. Why haven’t you ever been anywhere remote before?”

“Because with the net—and more generally the global information system—everyone’s equally in touch with everyone else. Even across event sequences, as it turns out. In terms of time and effort, which are the meaningful terms, everywhere is the same distance from everywhere else, and that distance is so small it might as well be zero. Now, since we don’t dare to connect to any of the global information system while the mission is on, places are now different distances from each other, and some of those distances are pretty big.”

She shuddered. “That’s weird. It really makes me feel alone.”

“I find it pretty weird myself.”

Helen sat for a long time, staring into space, and then finally said, “Uh, the other night—that wasn’t an act, was it? You really don’t like playing rough in the bedroom?”

“I really don’t.”

She sighed. “I was afraid you’d say that. Damn. Lyle, you have no idea how long it took me to find the other Lyle. And I always thought you had just suddenly changed your mind one day. But if the Lyle that likes rough stuff is so uncommon, how come I’ve been with him for so long?”

I shrugged. “We talked about that before. Obviously there’s some kind of conservation rule happening somewhere that keeps most people relatively near the same event sequence they left— the big jumps are less common. You were in some braid of worlds that included that Lyle. Now you’re on a different braid. Neither you nor I know anything about how many times you’d have to jump to get back on that braid. Or maybe I’ve crossed over into your braid, where you like that kind of thing, and one of the Lyles that you are compatible with is now somewhere else. We don’t have any way of knowing—everyone gets shuffled so much that no one has a ‘home’ or original event sequence, just some places that are more and less familiar.

“Now that I think of it, it even explains all the odd little coincidences; event sequences that contain a President named Abe Lincoln will tend to be closer to others that contain a president by that name, but he doesn’t have to be exactly the same guy or do the same things. Probably it had something to do with conservation of energy, or with the way the system tried to keep you from noticing the differences between worlds—it’s easier to get the trivial stuff to line up than it is the big things. To keep people from noticing that in some event sequences America was a kingdom ruled by Washington’s heirs, and in others it was a People’s Republic, you have wildly different worlds that all have Pepsi and Coke. That’s part of what keeps people from noticing—most of life is made up of trivia, and if the trivia is consistent, you don’t necessarily notice right away when the big things are different.”

She suddenly sat bolt upright as if the couch had given her an electric shock. “Oh, my god.”

“What?”

“Oh my god. Oh my god. Maybe five times since you started to like it—I mean since I met the you that liked it... all of a sudden you’ve been struggling and yelling like you’d never had it happen before. I’m in better shape than you are, Lyle, and I hope you don’t mind my pointing out that I’ve got more fighting skills than any version of you I’ve ever run into, and ... I thought they were acting! Shit, those poor guys must have wondered what had gotten into me and must have been scared out of their minds. There was one that... oh, shit, oh shit. What have I done to all those poor guys?” Tears were running down her face.

“You’d never have done it if you’d known,” I pointed out—a useless observation but the only one I had then. She just started to cry harder, so I eased over next to her and put an arm very awkwardly around her shoulders. Now that I was touching her without being scared to death of her, I could feel that she had a good deal more muscle in her back and shoulders than my Helen did. She also didn’t lean into me in just precisely the way that the Helen I was used to might have—it was clear that I was comforting, but she hadn’t exactly thrown herself into a fit of despair against my shoulder.

I missed my familiar Helen more than ever. At the same time, I had to admit that this one had a much better prospect of succeeding in the rough and dangerous world in which I found myself. And since I couldn’t do much more than keep the arm around her and tell her that it was all right, she wasn’t a bad person, this was just one of those things that happens, I had plenty of time to think—a bad thing, because in my circumstances thinking led directly to self-pity.

After a while she calmed down, and thanked me. We didn’t say anything but I think we figured out then that we wouldn’t be staying with each other; probably she really missed the Lyle who could give her the kind of experience she craved, who would share it and enjoy it. What had she said the other night? That it sharpened her eye and shortened her reaction time. Considering where we were going and what she might be doing, I could see how she might miss that a lot.

Next morning we were on the road early, and we went quietly and quickly, making as little fuss as possible loading the esty, since the Mexican Army officers at the fort had all said that it was a bad idea to give too much advance notice when you were on your way out the gate—better to just pop out sometime shortly after dawn, when gangs were less likely to be abroad, and then make time north as fast as you could, before they could get their act together to set an ambush.

“Who goes north anymore?” I asked.

The Mexican commandant shrugged. “People who come here from there, and go back. Traders and merchants of one kind or another. They come in bringing old electronics, spare parts, stuff like that to sell in the market. Things the poor people still use, you know. Sometimes even things like moving picture film, vinyl records, audio cassettes.”

I had no idea what an audio cassette was, and knew there was no real point in asking. “And where do they go, up north?”

“Up north,” he agreed. “I don’t think as far as the big river. I think they are just looting towns in the old northern states, places like Chihuahua, maybe. If they go into the old United States they don’t go far and they don’t look around much. Sometimes I ask them what it’s like up there, and they say there aren’t many people and there is all sorts of junk just lying around, which is what I could have guessed anyway.”

For the first few hundred yards heading north the road really looked no different than it had the day before—but this time we had to pass through a rolling gate and under the watchful guns of two towers to get out of the inner compound, and weave around through a series of adobe curtain walls, at the beginning of the trip. The sun was just clearing the horizon as we set out, with me driving the first shift, on the ruined north road through the rubble of Torreón. I tried to pick my way between potholes, and then to pick a way that minimized potholes, and finally just to pick the least savage potholes.

Everyone was in the same positions they had been in the day before, but nobody seemed to be sleeping. I don’t know what strange radar human beings have, but everyone seemed to know, immediately, that Helen—or at least this Helen—and I were no longer a couple. I couldn’t imagine that she had told them over breakfast while I was in the bathroom, but they all seemed to know just as surely as if she had.

This had the unfortunate effect of causing Ulrike to lean over the back of my seat and try to talk with me while I was coping with the vagaries of the rutted and broken road, plus the fact that the job of driving was still mostly new to me. Paula figured that she might as well let me have the first shift because the road was almost certain to be even worse further on, and an ambush more likely, and while she was a better gunner just as much as she was a better driver, if we got into an ambush we would need a driver to get us out of there just slightly more urgently than we would need a gunner. Consequently she was playing around with the gunsights, watching her results on the TV screen; as she said, the machine gun, in its turret on the roof, moving around up there and sighting in purposively on every rock, tree, and cactus in the landscape, might also give anyone who was watching pause.

“Is it as hard as it looks?” Ulrike asked.

“Driving? I don’t know how hard it looks to you. It’s kind of complicated but the individual parts don’t seem terribly difficult.”

“You might try some braking practice on this rough road,” Paula said casually, “so you can find out how that goes. It’s different from smooth pavement. Just keep in mind that you’ve got to have a light foot on the brake, eh?”

I gave it a shot, slowing the esty somewhat, and found it fishtailed slightly in the gravel, and bounced pretty hard in the holes, both of which made my foot slip a little on the brake. I didn’t lose control but I didn’t exactly have perfect control either.

“Perfect,” Paula said.

“I thought it wasn’t very good,” I said.

“You need to have more confidence in yourself,” Ulrike said, helpfully.

I saw from the corner of my eye that Paula raised an eyebrow. I made a slight face, just tightening my lips, and Paula grinned.

“It was perfect,” Paula said, “because it can’t be done any better than that. On this kind of surface that’s the practical limit. You didn’t do anything that might roll us or send us over a cliff, and you did get the speed down pretty quickly. So I’d have to say you did a perfect job—it’s just that the local definition of perfect is different from the global one.”

“See?” Ulrike said. “All you need is more confidence. Does anyone know how this area came to be abandoned? Is something creeping down out of America, maybe?”

“Like a pollutant or a vapor?” I asked. “That’s an interesting notion. Has anyone been having trouble communicating with Toronto these days? Or with Vancouver, or any other Canadian border town?”

Everyone volunteered what they knew, which didn’t reveal anything, though at least it got me away from Ulrike’s attention for a while. Communication to Canada was working just fine. Several of our group had friends somewhere in Southern Canada but it had never occurred to anyone to ask any of them what they saw when they looked south, or whether they had been across the border, or any of a dozen other questions that might have shed light on the whole situation.

“Then why aren’t we entering from Canada?” I asked Iphwin. “This is really the long way round.”

“It is,” he agreed, “except for two things. One, experiments with sending agents in from Canada have already been tried, and the result has been that they’re never heard of or seen again. They drop out of the public databases and out of communication with us as soon as they get near the border with the intention of crossing it. We tried sending in a man who was not continually linked by phone, and had his partner watch him try to walk through a border crossing way up along the Manitoba-Minnesota line. No luck there, either—the camera went dead, she can’t remember, and he’s gone. Sort of like the attempts we’ve made to reconnoiter by phone call.”

“You could have told us about all these things before we agreed to do this,” Ulrike said. “You’re telling us that you’ve lost everyone who’s ever tried?”

“We’ve only lost contact with them. We don’t know what happened to them. They may well be fine, and in the United States. Anyway, since the quick approach across Canada didn’t work out, now we’re trying something different—sneaking in via Mexico—and seeing how this works. As far as we can tell, this is a completely different experiment.”

“I still really hate that you do this kind of thing with other people’s lives,” Ulrike said. The whine was coming back into her voice, and as much as I found Iphwin annoying, I preferred listening to him.

So I asked a question. “You said there was a second reason?”

“Well, yes. We had records in several different event sequences of a Cabinet office that was created very late in the life of the United States—or the Reich, Christian Commonwealth, Freedom Reservation, or People’s Republic, or whatever that territory was called in its event sequence. The Department of the Pursuit of Happiness. It had four major offices—one each in Washington, Buffalo, Topeka, and Santa Fe. And it seems to have been mixed up in the whole issue of quantum computing, bandwidth, compression, all the technologies that have scrambled the worlds. As a secondary mission, besides just seeing what is going on in the United States, we also thought perhaps we’d try to get a look at one of those. But we had very bad luck up by Buffalo, as I’ve told you, and that was the closest by land. Now—if we get through, and if things look good—we thought we might try Santa Fe. The clues that seemed to indicate that the Department of the Pursuit of Happiness has anything to do with it are very ambiguous, of course, but all the same—”

I saw the flickers of light from the low rock outcrop ahead, and was shouting “Ambush” even as I reached for the brake with my foot. My guts fell into my shoes, but I couldn’t afford to freeze.

“Try to run it!” Paula bellowed. I moved my boot and stood on the speed pedal; the washboarded road with its big holes shook the esty violently, but I managed to hold it on the road and gain some speed. Ahead of me, the road bent along the edge of the rock outcrop, and then swept on through the desert in a big open area; if we could get past this ambush, we would have clear room to run.

Two shots banged off the outer windscreen, and Ulrike made a whimpering scream that was stifled by Terri grabbing her and covering her mouth, pinning her to the floor. Everyone got to stations in an instant, and Paula fired two short bursts from the machine gun. “Just making them keep their heads down,” she said. “With the magnification I can see four snipers with rifles, and I can point at them, but hitting them is out of my hands.”

“Everybody armed, over to the left side and find a gunport.” Roger’s voice was calm and clear, and people quietly moved into position.

Another shot caromed off the roof. “No damage,” Paula said, looking at her screen. She gave them another burst of machine-gun fire. Two scars appeared on the over-windshield but so far nothing had penetrated. The thundering guns above, the rumble and crash from that appalling road, and the grinding scream of electric motors working above their ratings combined to be so deafening that I barely heard our shots fired, and couldn’t hear theirs hit.

We rushed under the outcrop, and shots plinked off the roof like the beginning of a hailstorm; as we swung into the turn, the gunners on the left side opened up and the esty was filled with even more of a din, but not enough to drown out the desperate hope in my head that somehow I would not fuck up. Above it— faintly, though he was not even two yards from me—I could hear the Colonel bellowing for people to move to the rear gunports, and a moment later his shouting was drowned out by the big motor above my head, whirling the machine gun around to face the rear.

I became aware that they had shot out the rear window, that cheap chunk of civilian glass that had first worried us, when pieces of it flew against the windshield in front of me, and back away over my head. A big piece of the rear window slammed into the back of my headrest, making my head bounce, but I kept the esty on the road and the speed pedal floored.

“Keep it going a few miles, Lyle!” the Colonel shouted. I drove like a madman until the odometer had clocked off ten miles. The whole way, my bowels felt like they were on the brink of letting go and my shoulders waited for a bullet.

We had seen no cloud of dust from any pursuers, nor any trace of any other ambush ahead. A hollered conversation reached the agreement that I could drop down to normal speed again, which I was delighted to do. The rumbles and crashes fell to a tolerable volume, the world stopped bouncing around as if it were on some mad roller-coaster, and it was now possible to converse merely by raising voices.

Terri shrieked, a horrible sound that became a sob, and a moment later Roger was next to her. I couldn’t tell what was going on back there but it didn’t sound good.

“Better stop, Lyle,” the Colonel said.

I stayed on the road, preferring a quick getaway. Besides, I had seen no other car since we started that morning.

When we had come to a halt, I turned around.

Kelly and Ulrike were lying still where they had huddled together; Esmé and Jesús had rolled Ulrike over, revealing a big exit wound in her forehead.

Kelly was gasping for breath, hit in the chest.

“Damn, damn, damn,” the Colonel said. “They had two snipers down in the ditch, below our level. Must have gotten shots in through that broken back window. Caromed off the roof just behind the window, and came right down into the middle of the esty. Shit, I hate to lose somebody.” He wiped the rim of sweat from around his face with his shirtsleeve.

Paula was working on Kelly with the first aid kit. “It missed the lungs,” she said, “and probably the other vitals, so Kelly should be more comfortable with the pressure patch.” She sprayed that down. “As far as I can tell, she should be fine if we get her to an ambulance and a hospital. I’m assuming she has the Iphwin resources to pay for treatment?”

Whether or not that was what Iphwin intended, Paula’s tone made it clear that it was what was expected, and Iphwin agreed immediately.

We made Kelly as comfortable as we could. It was obvious that she was furious at all of us, and most of all at Iphwin, but she wasn’t going to annoy herself further by speaking with us. We propped her up a few yards behind the esty, by the side of the road, and gave her a phone, and Iphwin gave her a number to call.

When she had finished the call, we walked up to her to move her back into the shade of the esty, to wait for the ambulance. “I’m from a world near enough to this one—maybe I’m even the same Kelly you handed the phone to. Still wounded in the same place and I still remember that Ulrike is dead.” She grunted. “I think my brain hurts more than my chest. I don’t know how they’re going to do it,” she said to Iphwin, “but your team said they’d be here in five minutes, so don’t bother moving me. That is, about a thousand versions of them said it to about a thousand versions of me, I suppose, and since they’re in a self-driver, they’ll probably all get reshuffled on the way. But the overwhelming majority of us are going to get picked up by the overwhelming majority of them.” She grunted again; I realized she was trying to sigh, and then her wound would hurt and she’d be stopped before it came out as a sigh. “I knew this was a really stupid idea, and I went ahead with it, didn’t I? I suppose that ought to be a lesson to me. But then Ulrike was pretty willing to do it, and she got killed.” She stared into space. “I guess this is life for the time being. If I like where I am, don’t pick up a phone; if I don’t, just keep making phone calls till I find something better.”

“It’s not even that simple,” I pointed out. I wasn’t sure it was what she would want to hear, but it only seemed fair to tell her. “Any version of you who knows about it, and is in a nice world, won’t be making many calls. Only the ones that are unhappy will be on the line, and those are the only ones you’ll be changing with. You see? And since you know that...”

“I’ll only call when things really turn to shit. And so will everyone else,” Kelly said. “All we can do, at best, is exchange shit. And mostly it’ll just be a jump to a pile of shit indistinguishable from the one I was in—the same thing that would happen if nothing happened. It’s not exactly like being able to click my heels together and say ‘There’s no place like home,’ is it?”

There was a thunder in the sky above us, and a huge, three-rotor helicopter, its body shaped like an equilateral triangle, was descending from high above. We looked up, squinting against the noonday sun, and Iphwin said, “It’s all right, that’s one of mine.”

“Well,” Kelly said, “this is good-bye, Terri. I’m sorry we got caught up in having adventures and I hope you find a world you like. Maybe some versions of us will see each other.”

“We can’t think like that,” Terri said, “or we’ll all be seeing each other in the crazy house, you know? So just take care of yourself, and, well, arrivederci, à bientôt, vale, and adiós.”

The helicopter was thumping in lower now, out of the washed-out blue of the desert sky, and we backed off. In a few minutes, it had descended onto the road itself, not far from Kelly. A crew got out, put her on a gurney, and wheeled her inside. One of them saluted Iphwin, and he saluted back.

Then they were off, and we remaining ones were alone; Kelly would land in some world or other, and Ulrike was simply gone.

Working slowly and awkwardly, we got out the utility robot from the underside of the esty—a really nasty job, as its bolts were rusted on, and there were some scraped knuckles in the process. Jesús and I both took turns lying on our backs and trying to turn those bolts, banging on the wrenches in frustration when it turned out that the little power bolt drivers from the repair box didn’t have the force to do the job. At last we got the robot out, put the shovel attachment on it, and discovered that since it was a military machine, sure enough it had a preprogram for a burial. It crawled away a couple of dozen yards, sonar-sounding the soil to find a good place to dig, before settling on one location for a grave.

Jesús and I cleaned up in a little bit of water while the dirt flew around over there. At least the robot had both the patience and the speed to make digging a real grave practical; it was going down six feet and making a level bottom, no matter what.

By the time it had finished, we were as clean as we were going to get, which was pretty gritty, and we found ourselves elected as pallbearers, along with Helen and Esmé (since they were the two biggest women). We wrapped Ulrike up in a blanket, after brushing the clean parts of her hair out. One of the others, while we had been working on the robot, had gotten most of the removable gore cleaned up, but nothing could be done about the red crater in her forehead, and they had been unable to close her staring eyes, which were partially popped from their sockets^.

As Jesús did some quick, rough stitching to get the blanket closed, he asked me, “And you were married to her in some worlds, but didn’t know her in this one?”

“Yeah.”

“It must have been terribly difficult for her.”

“I think it was,” I said, “and it was worse because I didn’t feel attracted other than physically, and emotionally she was light-years from my type. I thought she was very pretty but she was somewhere around the end of the affair and I hadn’t started yet. But now I wish I’d done something or other for her. If I had known these were her last days, I might have.”

“And what could you have done for her?” he asked, putting in the last few stitches. “I suppose you could have given her the impression that you cared for her, if you really knew she would end like this in a few hours—but if she had not died, and you had no very strong reason to think she would—well, what then? You chose not to behave like a cad. Why fret about the difference? It cannot make a difference to anyone else.”

“You’re probably right.”

“In this world, I’m right. Probably in billions of others, I am wrong. Just as she is dead here and alive in many other worlds.”

“I think it’s more accurate to say that this Ulrike is dead, and many other Ulrikes are alive. It still makes a difference to this one.”

He cut the waxed cord and looked over the package he had sewn together. “Lyle, my friend, nothing makes a difference to the dead.”

Jesús, Helen, Esmé, and I lifted the body—surprisingly heavy, I guess because it settled to the middle of the blanket— and carried it to the grave without dragging it on the ground. Those who weren’t keeping watch came along with us, Roger standing guard over the funeral with his rifle.

We didn’t have any gentle way to lower her, so Esmé and I climbed down into the grave and Jesús and Helen rolled her into our arms. Fortunately the grave had been dug wide enough for a regulation coffin, and so there was just room to lower her down till the body lay across our toes, and then, with a big heave from Helen on one hand and Jesús on the other, to get each of us back out of the hole.

We weren’t sure what to say or do—we hadn’t planned on any funerals, after all—but before we had time to do more than feel a moment’s discomfort at the pause, the robot sprang back into business. Apparently its programming said that once all the live people were out of the grave it was time to get to work.

“Dear friends,” it began, “in the name of the President of the United States, of the Congress, and of the People, it is my sad duty to declare that speak deceased’s name clearly.”

We all stared at each other for a long minute before I figured out that that was a direction, and said, “Ulrike Nordstrom.”

“It is my sad duty to declare that Already Morstung has died in the line of duty, defending the nation which you and she loved. She was a good comrade and a loyal friend. She had a deep and abiding faith in the god or gods of her choice or else she was true to her philosophical beliefs to the last. She had a solid, deep, and loving relationship with her family with whom she would deeply wish to be reconciled if-there are any publicly mentioned family issues. Already Morstung had her human failings, as we all do, but still she stands as an example of what a soldier should be. We will miss Already Morstung and we will keep her in our hearts always. We now commend her soul to the god or gods of her choice, with the thanks and grateful prayers of the President, of Congress, and of the American people.”

A tinny version of “A Mighty Fortress Is Our God” began to play through the small speaker on the top of the robot, and it rolled forward to its dirt pile, which it began to energetically hurl back into the grave. We all stood and stared for a while, trying to think of something to say or do, I suppose, until Roger Sykes took charge. “Well,” he said, “it wasn’t a very nice funeral, but they never are. If anyone would like to say a few more appropriate words, we might all appreciate it. But if no one really has anything to say—and that’s understandable, none of us knew her—well, then, I guess we should get back to the esty and take care of the living.”

“That was four hours we could ill afford,” Iphwin said.

“Is that all you can say?” Terri demanded.

“I—I just don’t know what would be appropriate for me to say, because, as you well know, I don’t feel much, and besides—”

“You could try a really sincere ‘Ouch!’,” Helen said.

He looked baffled and said, “A really—”

She belted him, with all her considerable strength, right across the face, a great big side-armed haymaker that wouldn’t have taken anyone with any experience on a playground, but delivered a huge wallop. But of course Iphwin had no childhood memories to draw on, no idea that he needed to watch out or duck, and she flat decked him.

Roger, Esmé, and Jesús grabbed Helen and dragged her off, more to keep her from attacking Iphwin again than because they wanted to restrain her.

Iphwin lay there moaning in pain, and Paula and I attended to him. Not feeling too terribly concerned myself, I checked his pupils. They were the same size. I held up fingers for him to count and asked him a couple of short-term-memory questions. By that time he was sitting up, holding his jaw.

“Any of your teeth get loosened?” Paula asked.

“I don’t think so. The blow landed on the tip of my chin, and my jaws closed on my tongue, which is why I’m having some trouble talking. I suppose—”

Paula reached forward and grabbed his head below the ears; I’m not sure what she did, but he gave a little gasp of pain. “Just seeing whether there was anything screwed up with your jaw joint,” she said. “Did it hurt when I did that?”

“Yes!”

She grabbed him and did it again. He struggled feebly, squealing through his closed mouth. When she let him go there were tears of pain in his eyes. “Now does it hurt here, or here?” she said, stabbing her finger into two different spots on his jaw, not even slightly gently.

“Ouch! The second one!”

“Oh, good,” Paula said, “then you’re not seriously hurt. That’s normal.”

As we walked over to join the others and see what had become of Helen, I said to Paula, “That was really callous.”

“Yep. Nothing like callousness to give people an appreciation for callousness. Maybe to decide they don’t want to inflict it on others, maybe to decide they just want to avoid it themselves, maybe even to find out that they like being callous. Whichever. Anyway, it’s the big chance to find out what choice they’re going to make, and self-knowledge is the beginning of wisdom.” She tossed her long, dark red hair back, shook it, and started binding it into a ponytail. “If we have to work with him, the least he can do is work on becoming a little less of an asshole each day. I was just helping him with his homework.”

Somehow I had crossed over to a world of women who scared the living daylights out of me.

Helen had not only calmed down, but had adopted an attitude similar to Paula’s—”If a goddam artificial intelligence is going to put on a body and walk around among us, it had better adapt itself to us and our way of doing things. People have been adapting to computers and robots for more than a century, and it’s high time it was the other way round. And besides, whacking him in the face is just a way to access the nervous system more directly at a simpler level. You could think of it as pushing his reset button, or programming him in machine language.”

I don’t know exactly what effect it had; Iphwin could tell that Terri didn’t like him, and since he sat in the middle with her, he was trying not to anger her by speaking, I suppose.

Paula said I was now a proven getaway driver, and she was still a better gunner. I told her I had been terrified.

“Well, then, it’s even better that you did such a fine job, if you were also coping with fear at the same time. We’d better keep you on the task.”

I drove till almost sunset, miles and miles of rocky and scrubby desert broken by some fields of dunes, and distant views of the high mountains. It was beautiful country, but there was way too much of it. We were only averaging about thirty miles per hour—a necessity on that long-neglected highway, even with puncture-proof permatires and an extra-heavy suspension. After the delay, we could no longer hope to reach Juárez before dark, and in fact sunset would find us only a few miles north of the ruins of Chihuahua. Iphwin, however tactless, had been absolutely right.

“My vote is to camp here for the night and make a short, fast run in the morning,” Esmé said. “Maybe stop forty miles short of Chihuahua, first good place where there’s cover, eat cold, set watches, depart early. That’s what I’d like.”

“Same here,” Paula agreed. “This is rough country in several different ways; I’d be very happy not to have to do anything that gave any advantages to any bad guys out there.”

Everyone agreed; Terri and I were both badly shaken, the more violence-proficient among us probably were too but weren’t about to show it, and god alone would have any idea what Iphwin was thinking. Just by the rusting old sign that said “CHIHUAHUA 60 KM” there was a heap of rocks tumbled together, perhaps a much-eroded cinder cone, and behind it, out of view of the road, we parked and made what camp we could.

I was selfishly glad that our soldiers and cops largely volunteered to sleep outside on the ground, and being a little ashamed of being selfishly glad, I agreed to stand a watch, up on the rocks above, in a secure spot that the Colonel and Esmé picked out. Paula and Roger would stand watch till ten, since she was driving the next day; Helen and Jesús would stand ten to two, and that left the short early morning watch to me and Esmé. I suppose I should have been flattered that I was the one of the noncombatants that they trusted to take a turn at watch, but since the alternatives were a teenager who seemed to be nearly in shock, and Iphwin, whom no one could figure out, I thought it more likely that I was chosen by default.

I stretched out on a middle seat, with the sun still up. I would stand my watch from 2:00 A.M. to 5:30. At 5:30, everyone would be up and getting ready to roll out at first light.

It seemed like a long time away, and I didn’t think I could sleep that long, or at all, but I snugged the pillow under my head, undid a couple of shirt buttons so that I could move my chest freely, and had just a moment to notice that the warm sun on my face was pleasant, so perhaps I would enjoy it for a few minutes before pulling a coat over my head to get some darkness.

Sometimes when you think you couldn’t sleep to save your soul—perhaps because of a dreadful day like the one I had just been through, or when the future seems to be pure menace hidden by dark fog—you fall asleep so fast that it comes as a shock, as if a trapdoor opened in unpleasant reality and you fell down a dark well and plunged to somewhere else at the bottom. The exhaustion lurking behind my eyes leaped up and yanked me down the dark well of sleep, and it was seven hours later and Esmé was giving me a friendly shake. “Come on, we get to go climb a hill in the dark so we can sit on cold rocks and watch an empty road. You don’t want to be late for that!”

I sat up, stretched. Though it was the middle of the night, I was feeling pretty good. I checked my watch, and it was quarter till two; there was just time for a swallow of coffee from a thermos and a quick leak behind a rock, and then I was picking my way along behind Esmé, a pistol strapped awkwardly onto my belt most of the way behind my back, bumping me in a way I wasn’t used to. Esmé had cheerfully told me that in the event of trouble I was to keep it in my holster unless she was immediately killed, in which case I should fire it to alert the camp. “Or if you get a guy coming at you so close up that you could club him in the nose with the muzzle, try to do that. You might as well pull the trigger when you do.”

I managed to keep any wounded dignity out of my voice. “I did carry one of these, off and on, when I was in Her Majesty’s Navy. And I had to fire it a few times a year, on a range.”

“Well, good. Then you’ve had enough training not to shoot me by accident, or yourself in the foot. How good a shot were you?

“I was planning to use this thing as a club, if it came to that. Your suggestions weren’t wrong, but you were suggesting them because you thought I didn’t know anything. The reason they were good suggestions was not that I don’t know anything—they were good suggestions because I’m a shitty shot.”

The big woman chuckled in the darkness. “You’re different, Lyle Peripart. I might even get to like that.”

Now we were far enough up the hill to be staying quiet, at least until we got to the sentry post and found out how things were going. The boulders were middling big and pretty well jammed into place by the millennia, so that the footing and grips were much more secure than they looked; the trick was only to find a way to stay low while going over them, and there was enough light from a half-moon, still relatively low in the sky, to make it almost easy going. Ten minutes of sweaty scrambling on the dark hillside got us to the top, looking down over a little pit in the rocks, where we saw Helen and Jesús, both looking across the road, sitting crouched side by side in the space behind a large boulder.

“We’re up here,” Esmé said.

“We heard you coming,” Jesús said, softly but not bothering to whisper. “You can probably do better next time. But I don’t think it matters right now. There hasn’t been a breath of half a sound, and there’s no trace of anything moving out there. Paula and Roger had a very quiet watch as well. I think the bandits that fired on us probably just take a shot at everything going by, and don’t pursue anything they don’t hit hard enough to stop. And we’ve seen nothing and no one since.”

“Where do you think Iphwin’s helicopter came from?” I asked. “It showed up within five minutes.”

Helen snorted. “At a guess, a hidden base near the road, which he could probably have flown us to but didn’t, for some obscure reason of his own. Or possibly he had a hundred helicopters in a hundred different worlds do something or other to cause them to cross over to other worlds, and this is the one we got. Or maybe it jumped straight in from orbit using a technology none of us knows even exists. Or the most likely possibility— something completely different that none of us has thought of.”

“He is confusing to deal with. Did you really have to slap him around?”

“If I answer that question, we’ll spend an hour quibbling about the connotations of ‘have to.’ And I’m good and tired and headed down the hill for bed. Have a quiet watch,” she added, as she climbed up and over the rocks.

“You probably will,” Jesús added as he scrambled up to follow her. “The moonlight helps, and there’s a wide stretch without much cover; anyone who sneaks up on us from that side will have to be pretty good.” A moment later they crunched over the rocks beside us and were gone; I heard the faint scuff of their feet once or twice behind me, as we climbed down into the narrow space behind the big rock, and then nothing. We settled in, taking only a moment to agree that in general I would watch to the south and center, and Esmé would watch north and center.

I was surprised at how awake I felt. True, I had just had some very deep sleep and some strong coffee, but I felt rested, comfortable, ready to be up for a long time, and it was not yet three in the morning.

The landscape in front of me took a while to resolve to my unfamiliar eyes, but there wouldn’t have been any problem spotting anything moving. It was all dark curved shapes out there with patches of bright moonlight between them, and the shadows were small—the half-moon was already getting on toward halfway up the eastern sky, its light beginning to spill over the hill behind us. Further, there was a big swath of dune sand that splashed almost all the way across the road to the south, and though someone might have been able to lie hidden in its shadow, I didn’t see any pathway to that shadow that wasn’t exposed. The air was cool but not unpleasant; there should have been more wildlife out there making noise, I thought, but then big animals are scarce in that sort of country, and more than likely the quiet struggle between the predators and prey was going on all around us, in the little dark corners between rocks. No doubt it would become fiercer, and perhaps more audible, in the hours just before and after the sun came up.

“Whoever fired on us hasn’t been bandits long, or is very lazy, or isn’t very talented,” Esmé said, her voice barely above a whisper, a long time after we had settled in to watch.

“Why do you say that?” I tried to keep my voice lower than hers.

“Because this is twenty times as good a place for an ambush, and it’s not that far away. If they had just scouted up the road a little, they’d have found this. And there’s no place anyone in his right mind would stop, or turn off, between there and here. Any truck or car that went by there would go by here. Either they must have set up at the first convenient place and never bothered to move, or else they’re too stupid to see that from the rocks down below us, they could rake a vehicle from one end to the other with fire, and the vehicle could never get off the road because of the dunes to the side. If they held fire till the right moment, people in a vehicle would never be able to go either forward or back. They’d just be pinned down until enough rounds found enough vulnerable spots. I’d put the main force down by the road, and the lookout—geez, I’d put it right—”

She stopped and gestured for me to listen. I did, listening harder than I ever had in my life, as if I were throwing my mind into the surrounding rocks and desert, trying to pick up anything other than the soft susurrus of our breathing and the gentle creak of wood and leather as Esmé drew a knife from a sheath and wriggled through a shadow, out to the side, and down the hill. I thought about whether or not to draw my pistol, but I suspected that moving as quietly and carefully as Esmé was, she would be taking a long time getting down the hill to whatever sound she was checking out, and I knew I would be getting steadily more nervous the whole time. I didn’t want to be holding a pistol when she came back, if I was going to be jumpy; I couldn’t see any way that could be a good thing. At best, I’d be more worried about not shooting her accidentally than about identifying anyone else who might be approaching. And at worst, I might cost us a fighter and give away our position. I left the pistol where it was and tried to do nothing but watch very actively and very quietly for any sign of motion.

There was a blur of motion in the shadows about sixty yards in front of me and perhaps thirty feet lower. I moved forward cautiously, keeping my head in shadow, and peered at it, but saw nothing. A very long time went by, and I turned everything over and over in my mind while I tried to stay ready, calm, and watchful. Esmé had found something or someone creeping up on us, and had had a quick, silent, deadly fight with it down there. Probably someone on their way up to our present position.

If Esmé had won, she would now be creeping down the trail of shadows, over the boulders, to the place she had picked for setting a main force for the ambush, probably hoping that the force there would be small, maybe just one or two, so that she could take it out herself—or if it were large, she could see it, crawl back, let the rest of us know, and come back with some firepower. No doubt she was going to take a while about it—if she had won.

If she had lost, whatever beat her was now on its way here. I moved the pistol around on the belt, carefully, never taking my eyes off the slope below, scanning as hard as I could, my hand resting on the butt. I could now draw it fast, I knew where the safety was, and I would draw it as soon as something moved, and fire as soon as it wasn’t Esmé. I thought that anything that had overcome her, when she had the advantage of surprise, would probably get me, but a shout and a shot might make all the difference to our people back at the esty.

I squatted, changing my position slowly, just often enough so that nothing would stiffen or go to sleep, and watched and tried to be in the state of empty readiness for anything that is supposed to be characteristic of martial artists. The slope was motionless and silent. The shadows were imperfectly dark; a blade of grass, a bit of saguaro, or a white rock might shine a little in them, and might seem to move now and then, helping to keep me alert but nervous. The bright spots where the moonlight hit fully were distracting and tempting as places to rest the eye, but if you did that, they seemed after a while to float up away from the shadows, and instead of a dimly lit rocky, scrubby hillside, you could find yourself looking at an uninterpretable set of blobs of light and darkness that made no particular sense and might not interpret into reality fast enough.

I tried to check the road and the desert beyond it regularly too, and to keep an ear out behind me in case someone with even more night-fighting talent than Esmé had crept around behind me and was about to drop on my shoulders.

I wasn’t moving much, but I was busy, as the shadows shrunk and reached westward, and the half-moon—now too bright for me to look at as my eyes had become completely dark-adapted— crawled up the sky toward the zenith, shortening the shadows and lighting more of the landscape. I guessed that it had moved about thirty degrees, roughing it as a third of a right angle, since I took my post, which meant around two hours had passed. It seemed like much less.

How long had it been between taking up our position and Esmé’s going forward? I had no idea, but not as long as I had been waiting here, I figured.

A half-moon with the curved side east, like this one, is bang overhead just when the sun comes up, and since I was really beginning to hope the sun would come up, I stole a couple of upward glances. The moon was perhaps ten degrees, which would take about twenty more minutes, from the zenith; the first glow before dawn should be happening any moment. I watched and waited.

A voice behind me said, very softly, “Lyle, please take your hand off that gun. If the safety is off, please put it back on.”

“Safety is on,” I said, and very slowly took my hand away from the pistol butt. “Esmé?”

“Yes, it’s me.” She sat beside me, her teeth chattering as if she’d just been drenched in a freezing bath and then sent out into a winter wind.

I ventured to ask, “Any chance there are any more?”

“I don’t think so. God, I have to hope there aren’t. I can’t... oh, god, Lyle, no, I think we can just talk, now, if you want to. And I want to, need to, even I’m just having a lot of trouble doing it. Give me a minute and I’ll tell you what happened. But it’s pretty goddam gruesome and I’ve never felt so shook in my whole life, and I would really appreciate it if whatever you say or do is the most soothing thing you can come up with.”

“I’ll do my best,” I said.

She leaned back against the rock, and then moved so that her shoulder rested against mine, obviously needing the comfort of the touch. Just in case she’d made a completely wrong guess about whether there were any more attackers, I kept my eyes on the slope, but I listened as she said, “I found a barely marked trail—mostly just little bitty cut handholds and footholds, and some trampled spots in close to rocks, it was a very clever setup to keep people from noticing that there was any trail there—and I followed it down, staying about five meters off to the north of it. Sure enough, after a while I heard some noise—not much, a boot scrape maybe, or a breath. I had someone coming up that trail. I crept on over and got into a shadow. Somebody passed by me, and I jumped in behind them and went for a silent kill.

“Well, guess who it turned out to be when I jumped onto the trail? Our old multi-lived friend, Billie Beard. This version of Billie knew her stuff, too—I jumped her from behind, hard as I could, and got her trachea squeezed and stuck her in the kidney before she could get into the fight properly, and I still felt like I was trying to hog-tie a steer with masking tape. I sawed through her carotid while I had her in a half nelson, which is incredibly messy and scary. I hope we get to someplace where I can wash, and soon.

“At that point I figured, okay, Billie Beard was going to be a lookout, and there had to be an ambush right in the place I had picked out. I crawled down the hill and was delighted to smell some kind of cheap booze—rotgut bad enough that it might have been vodka, tequila, maybe just straight grain alcohol. Quiet little noises, almost like someone wrestling.”

She leaned in close and said, “This is not romantic, but if you would just put your arm around me, I would really, really appreciate it. Right now I’m afraid I’m either going to cry or throw up. I promise if it turns out I’m going to throw up, I’ll get away from you. But I think more likely I’m just going to cry, and I guess I’m literal enough that I want a shoulder to do it on. And I’ll say I’m sorry, in advance, if I accidentally get any blood on you.”

I hugged her in one arm, and sat back, where I could no longer see the slope below us, figuring that it made much more sense for me to trust her judgment than my paranoia; if she thought all threats were ended, then anything that could surprise us was something I wouldn’t stand a chance against, anyway.

After a few deep breaths and a couple of “Uh” and “Well” false beginnings, she said, “I was almost laughing, with relief that this was going to be so-easy, and at the chance for some revenge. I crawled forward and there were two high-powered rifles and a couple of grenade launchers, leaning against a rock—and two people moving around in the shadows. The reek of booze was amazing.

“I could have laughed out loud when I realized that there in the near shadows I was seeing two pairs of Levi’s, and two holsters with pistols, and that in the deeper shadow there was a couple fucking doggie-style, giggling, drunk out of their minds.

“Now, in my years with the Colonel, we were on various sides of a bunch of civil wars all over Central and South America, and those are the kinds of situations in which you really, really lose all concept of sportsmanship. If they’d made themselves that vulnerable, then the evolutionary process needed to remove them before they could breed—and here I was, just in time.

“I figured out my footing and position, got into place, and then dropped in right behind the man, bracing a knee in his back and cutting his throat before he knew more than that he was startled. And just that second, damn if that woman didn’t grab a knife from a back sheath, roll to put the dying man between her and me, and come right at me fast and hard, ready to kill me. Never saw anyone handle anything so fast before, Lyle, and I’ve seen plenty. Shit, Lyle, if my mind isn’t playing tricks on me, I even remember thinking that I had finally met my equal.

“I got a footsweep on her and gave her a good gash in the arm on her way down—I think I must have nicked an artery, to judge by how much blood there was. She came back at me, maybe already getting weak, and I managed to get inside her blade and drive mine into her eye, hard enough to crunch bone and get right into the brain. Nasty, messy way to go, but fast, and she didn’t make a sound as she died.

“Something made me drag the bodies into the moonlight— some part of my mind must have already known, and thought the rest of me should know. I wiped the faces clean.

“The man was Jesús Picardin—or rather a different version of him. And the woman was me. No wonder she was so handy with a knife, and no wonder our little clash of blades seemed almost choreographed, as if we were anticipating each other’s moves and my little advantages—having clothes on, being less surprised, not being drunk—sort of gave me the win on points.”

She shuddered again, violently, and pressed her face against my shoulder.

I hadn’t the slightest idea what to say or do. We sat like that until the sun was fully up and it was time to go down to the others. Despite having been well rested before my watch started, and having only been awake a few hours, I went right to sleep as soon as we rolled north in the esty, sleeping back in the middle seat. Terri sat up with Paula for driving lessons; I think everyone thought that some distraction or other might be good for her, and besides nobody much wanted to be near Iphwin. It didn’t bother me because I was asleep.

I was told later that the ruins of Chihuahua were particularly impressive, for it had once been a big, prosperous city, and thus it had come in for more than its share of looting and burning as the north of the country had gotten more and more dangerous; somehow, though, I was content to be spared the sight of a vast expanse of burned and wrecked human dwellings, silent and empty in the early morning sun.

It was almost noon when the Colonel awakened me and said, “Hate to disturb you, Lyle, but we need to hold a little conference before we go further, and I thought you ought to be part of it.”

“Perfectly all right, Roger.” I sat up, rubbing my eyes, and noticed the esty was no longer moving. We were stopped dead in the middle of the road, sitting in the usual environment—desert surrounded by mountains, on a road that connected a meaningless spot on the southern horizon with an equally meaningless spot on the hills to the north of us. While I was asleep they had “fixed” the rear window by taping clear plastic over it. I gathered my wits and managed to ask, “What’s up?”

“According to our map, which is forty-five years old, this line of hills up ahead is the last one before the Rio Grande. Then we’re about three miles from a bridge that should take us over the river and into the United States. If the bridge is still there. If the United States is still there. You might say there are a few complications.”

I yawned and stretched and said, “All right. I’m with you, more or less.” I dragged myself to the edge of the seat and found that all the others had managed to range themselves in a rough circle among the esty seats and aisles.

“And there’s a few things we want to ask Iphwin about,” Esmé said, making it sound like a threat. To judge by the way Iphwin reacted, he surely heard it as a threat too. Esmé smiled at him, an unpleasant smile that registered satisfaction more than pleasure, and said, “Such as who the hell is Billie Beard—what the hell is Billie Beard—and how come I just ran into versions of people who already exist on this side. I still get a feeling someone is not being perfectly honest with us.”

“Before you answer,” Helen said, “think about what you learned about pain, yesterday.”

Iphwin tried to speak, twice, and then finally drew his knees up to his chest, tears leaking out around his eyes, shaking his head. There must have been three full minutes, or more, during which we just sat and stared at him.

Terri realized before any of us, bent over the huddled little man, and said, “I bet you’re really afraid.”

Iphwin nodded miserably.

“That was the first time you’d ever really been hurt and besides you don’t understand what we want or why we do things, so now all of a sudden you’re really afraid that we might decide to hurt you again. And nobody’s talked to you all day and you’re probably also really lonely.”

His shoulders started to shake and tears gushed down his face. Terri put her arms around him and told him, “No one is going to hurt you. We’re sorry. And we’ll be your friends again, if you forgive us and if you promise to try to learn to respect our feelings. Promise?”

“I promise,” he sniffled.

“Oh, Christ,” Helen said, her voice dripping with contempt. There was an echo in it, somewhere, of the way she had been with me in the bedroom. “The ruler of the economic universe turns out to be a big baby.”

I looked at her with some irritation, but before I could think of some suitably adult and urbane insult to toss at her, youth and energy jumped into the breach.

“I guess you’re never too old to be a bully,” Terri said, straightening up and glaring at Helen over the tops of her small wire-rimmed glasses. “And I suppose once you take it on yourself to bully other people, there’s no such thing as a victim that’s too helpless.” The skinny girl looked even younger than her age—like an angry choir boy who might fly at Helen and start slapping or pulling hair—but she pushed her glasses up her nose, raised her chin, planted her feet, and made it dead clear she wasn’t giving any ground.

After a long pause, Helen shrugged, as if it were simply too trivial to take notice of, and said, “Iphwin, I am sorry I hit you, and I shouldn’t have done it. And if you need to cry, well, that’s none of my business. It was rude of me to make fun of you.”

“It’s all right,” Iphwin said, sniffling. “I do feel awful but I think you were right yesterday that I needed to know this sort of feeling was possible. I had no idea that one human being could do this to another one. I don’t mean as a matter of conscience, I mean I had no idea what the effects could be like. And I’m very afraid I might have done things like this to the rest of you, and I really didn’t know what I was doing, and that’s no excuse at all because I should have known, and ... oh, oh, oh, shit.” He started to cry again, and Terri sat down next to him, patting his arm.

“He’ll be fine in a minute,” she said. “Just needs to get it out of his system, and he isn’t used to it. Why don’t you all take a walk or something?”

There was a long pause, and then Roger got up and went out the door of the esty, silently. Esmé, Paula, Helen, and Jesús followed, sullenly. I trailed after them.

Outside I discovered that everyone, except Roger, was competing to think of how to complain about Iphwin and “that stupid kid.” I thought Terri was the only one in the bunch that had shown anything like normal human feelings, and when I couldn’t stand the nastiness any longer, I went back inside. The Colonel shrugged and followed me in.

Iphwin was washing his face in a bowl of water, saying softly, “You’re right, that does help to make me feel better. Hello, Lyle. Hello, Roger. I’m really sorry about all this. Are the others still angry?”

“Yeah, but I think they’ll cut you some slack now,” I said. “Terri, before anyone gets a chance to bitch at you about it, I think the way you’ve just treated Iphwin is really a fine thing.”

Roger nodded, emphatically. “I don’t think I have half your compassion and empathy.”

She shrugged. “Hey, I know what it feels like when I feel all alone and like nobody understands me. They say that’s normal for a teenager.”

“It’s normal for a human being,” I said, thinking about Helen and how much I missed the other version of her—and how much she must miss her preferred version of me.

“And is this what it feels like every time you get your feelings hurt?” Iphwin said. “No wonder you all spend so much time on human relations—it’s just sheer self-protection.”

I shrugged. “Most of us got our feelings hurt many times every day when we were children—because we were vulnerable then the way you are now, and not able to defend ourselves. We learned not to feel it so much, or not to admit it, or something. It takes practice to learn to cope with cruelty, but luckily, I guess, human beings will almost always supply enough cruelty to give you all the practice you will ever need. Everyone else here probably experienced things the way you do, once upon a time, but all of us are past it-—or at least we’ve reached a point where we don’t have to be overwhelmed by it.”

“Lyle, I’m really sorry. I had no idea how much disturbance I was causing all of you.”

“Another uncomfortable lesson,” I said, “is that since ‘sorry’ doesn’t fix things, you can really only say it a few times. And you do have to get used to the thought that now and then you are going to hurt somebody’s feelings, and you won’t be able to fix that—you just have to hope to be forgiven sooner or later. Your mechanical progenitor just had no idea what he was going to get you into, did he?”

“Not really.” He splashed the water on his face again. “That really is remarkably refreshing,” he said. “I know that tears carry off some stress-related biochemicals, so I suppose that rinsing the face helps get rid of them.”

“That, and while you’re covered in tears and snot, you don’t have much dignity,” Roger said, practically. “The others are standing outside in the sun, and probably getting bored and angry and cranky and all that. If you’re feeling well enough to talk, maybe we should have Lyle get them in here, in the air-conditioning, where there’s somewhere to sit down.”

Terri added, “It’s called being considerate.”

“I know,” he said. “I’m ignorant about emotions, but I have a great vocabulary.”

I went outside and saw that the bitch session was still going on. “I don’t understand it,” Esmé was saying. “What kind of mission is this? Civilians along for no particular reason anyone can name, except this thing about the mathematics of abduction. No clear-cut job like ‘get to the center of the disturbance’ or ‘find out where everyone went.’ We get shot at and he doesn’t even identify the enemy. I mean, what’s the whole idea?”

“I think we can talk now,” I said.

“Well, fucking great,” Esmé said, and strode toward the bus, Helen at her elbow. The rest sort of shrugged and trailed along.

The story we got out of Iphwin was reasonably simple: the program that had made him wasn’t the only cyberphage that ran in the net as a whole. His job was to reconcile messages, which was why over time he had become concerned with the number of people and places that were disappearing, and set out to find out where so much stuff had gone.

Billie Beard was another cyberphage—in fact, she had brought herself into physical being by copying Iphwin’s process for doing so. “It didn’t bother me to have my work plagiarized when I was entirely a machine intelligence,” he added, “but oddly enough, now that I have a fleshly body, it bothers me. Anyway, you could think of her as the department of pain control. Her job was to prevent things that were too distressing from traveling through the net. Now, as you all well know, the fact that every time you go into contact with the net you come back to a different world is, well, extremely upsetting. The artificial intelligence that was to become Billie Beard spotted this early, since it was part of her job, and began to re-engineer the net to make it harder for people to ‘hurt themselves’ by realizing what was going on.”

“Wait a minute,” Helen said. “She’s also been beating the shit out of us whenever she gets the chance, and she’s tried to kill us—”

“Has killed one of us,” Iphwin agreed. “I think that must have been her, and some assistants, who ambushed us yesterday. As Esmé has pointed out, the behavior didn’t make any sense for bandits but it made perfect sense for someone trying to kill or stop us.”

Helen sighed. “What I’m getting at is, I don’t see how a program that is supposed to prevent pain is doing all this brutality.”

“A little failure of definition,” Iphwin said, sadly, looking down at his feet. “I can see why it’s confusing, but believe it or not, Billie Beard wouldn’t understand what confused you. Her definition of pain is emotional distress you experience while you’re on the net, which is when she can experience your emotions with you. If she kills you or hurts you while you’re offline, she doesn’t experience the pain—and therefore it doesn’t exist, as far as she’s concerned.”

“It sounds as if from her standpoint the world would be a better place if she could kill the whole human race—as long as she did it off-line,” Roger said.

“That’s it,” Iphwin agreed. “When they go mad, machine intelligences go mad in the direction of excessive consistency. She’d need to kill everyone and suppress the news of it, because people receiving the news would feel pain of a kind she could recognize.”

There was a long silence as we thought that over. “Will she be on the other side of the border?”

“Not to my certain knowledge, but if I can get there, she can get there.” Iphwin sat back, folded his arms, and said, “Well, that’s as much really as I know about her. And before one of you points it out, yes, now that I have a body, I have a somewhat better idea of what ‘real’ is, and I know that you don’t much like being in a war between two machine intelligences whose objectives and purposes aren’t as real as the bodies that are being sacrificed to them.”

“True,” Helen said, “but most wars are fought over ideas just as abstract, so let’s not quibble. Now, how was she able to bring along Jesús and Esmé—or versions of Jesús and Esmé— when they already existed here?”

“I myself don’t fully understand the consistency rule,” Iphwin said, “but basically all it says is that the less noticeable a crossover is, the more likely it is. No crossover is prohibited, just more or less likely. I imagine that Jesús and Esmé were two of her best soldiers, and she probably just kept batting at the system till she got a version of them in the place where she wanted them. That’s how I got you all here—leaving a wake of versions of all of you stranded all over trillions of event sequences. Think about the odds of a royal flush in cards, and they ought to be rare. But if you could shuffle and deal a million times per second, and stop whenever you did get a royal flush, you would get them reliably.”

There was a long pause and we all realized we didn’t have any more questions just then, and we had come to the moment of decision.

“Do we have any kind of plan?” I asked. “If the bridge is right ahead ...”

“Well, if something tries to stop us from crossing, we either fight it or run away from it, depending on how strong it is,” the Colonel said. “And if we get to the other side, then if we’re under attack, we fight back, and if not, we group up and decide what to do next. There’s a good chance that Beard and her sidekicks will be guarding that bridge, and that means we really don’t have any options until we either get past them or around them. After that, when we’re on the other side, since we might know something then, is the time to try to figure out what to do next. Till then it’s just theorizing in the absence of data. Let’s see if there’s still a bridge there, and if so, let’s see if we can just drive straight over it. Till we try, we don’t have any way of knowing that we can’t—or why we can’t.”

It was disagreeably true, and no one had much to add. A few minutes later, we were in the esty at the top of a low rise. I was driving, again, so that Paula could work the top gun. Terri and Iphwin crouched in the center, and I quietly hoped that they didn’t notice that they were on top of spots and spatters of dried blood. Bits of rubbled safety glass from the rear window still lay all around the inside of the bus. I did my best to forget about all that and just drive forward slowly and carefully; meanwhile, Paula kept working the guns around the ninety degrees facing us, looking for anything that moved or was the least bit suspicious.

“Any reason to think they won’t have planted a mine?” I asked Iphwin.

“No reason I am aware of except a pattern in her behavior: she seems to prefer one-on-one killing to blowing up large numbers of people,” he said. “But remember she could have put an atom bomb under the road yesterday and wiped us off the face of the earth—and that’s not what she did. I really hope it isn’t only because she didn’t think of it.”

I drove slowly down the street. There was a bridge there, at least, and nothing obviously between us and it. The river had shifted during the years since anyone had been here—it flowed against the opposite bridgehead and had eroded away most of the road facing it—but it looked like there was still more than enough solid ground to get the truck through. No buildings showed beyond the ridgeline, but there were phone or electric poles, without cables, standing like bare sticks, going up the hillside. For a first sight of the country I had pledged allegiance to all my life, it wasn’t impressive, but no doubt there would be more.

Unlike Torreón, Juárez had not been leveled, and unlike Chihuahua, it hadn’t been burned. It had merely been abandoned, and we had crawled through its empty streets past miles of crumbled and collapsed buildings without seeing anything of note. The road wasn’t even particularly badly potholed, and toward the bridge it was almost decent, as if it had had no traffic at all and been sheltered. I took it slowly all the same.

As we reached the bridgehead, I slowed further.

“Roadbed looks decent,” the Colonel said. “It should take our weight easily.”

There was a huge crash that made my ears ring so hard that I couldn’t hear a thing. The bus slewed sideways as if a giant child had slapped its back end. The motors all stopped dead, and I looked to see what had become of the others. From the way their mouths opened, they were screaming. From the way my throat felt, so was I.

The roof had been torn right off the bus, leaving a rim of jagged metal. The windshield and windows were shattered and the bus stood, its sides peeling away in immense jagged pieces, sideways across the bridge.

I barely heard the Colonel shout, but he pointed, with big violent waves of his cane, across the bridge, shouting “Run! Run! Go! Hurry!”

I jumped off the bus and dashed for the other end of the bridge, running for all I was worth. There was an old painted line, probably the center line of where the river had once been, I thought, in bright green paint—then I saw that it didn’t go all the way across the bridge, stopping just short of the edge. Where it ended there was the shape of a human body printed in the green paint, and an old bucket lying on the other side. Someone had been painting that line when something had knocked him flat; then he had—gotten up and walked off and never tried to paint that line again? died and been carried off? decayed in place? I had no idea.

There was a sort of orange fire dancing all around the bridge, and though I still could not hear, I could sense that there was a loud roar around me, and feel other people running beside me. Not wanting to touch that line, I jumped over it. Things hit the deck and walls around me. Someone was shooting at me. I dashed on, zigging and zagging, trying to present a lousy target, and a few terrifying seconds brought me to the foot of the bridge, where I got behind a column and flattened myself to the ground.

I drew a long breath and exhaled, drew another, peered again. We had some people down on the bridge, and I tried to see if there were any of them that I should be going back to get, but naturally they were lying still—I couldn’t tell if they were dead or playing dead.

Paula jumped in beside me, clutching a rifle, and shot back, shouting to the others to run, run, run, she would cover for them. I tugged her pistol from its holster, rolled to the other side, and started to shoot too, not sure at what, just thinking that perhaps we could draw fire away from any living comrades who were stranded on the other side or lying on the bridge itself.

Then I was nowhere and remembered nothing.