Timeline

TRANSIT.

Gordon rubbed his hands together. He said, "Let's get right to the packing."

The room was small and reminded Marek of a hospital laboratory; it made him uneasy. In the center of the room stood a vertical tube, about seven feet high and five feet in diameter. It was hinged open. Inside were dull strips. Marek said, "A suntanning machine?"

"Actually, it's an advanced resonance imager. Basically it's a high-powered MRI. But you'll find it's good practice for the machine itself. Perhaps you should go first, Dr. Marek."

"Go in there?" Marek pointed to the tube. Seen up close, it looked more like a white coffin.

"Just remove your clothes and step inside. It's exactly like an MRI - you won't feel anything at all. The entire process takes about a minute. We'll be next door."

They went through a side door with a small window, into another room. Marek couldn't see what was in there. The door clanged shut.

He saw a chair in the corner. He went over and took his clothes off, then walked into the scanner. There was the click of an intercom and he heard Gordon say, "Dr. Marek, if you will look at your feet."

Marek looked down at his feet.

"You see the circle on the floor? Please make sure your feet are entirely within that circle." Marek shifted his position. "Thank you, that's fine. The door will close now."

With a mechanical hum, the hinged door swung shut. Marek heard a hiss as it sealed. He said, "Airtight?"

"Yes, it has to be. You may feel some cold air coming in now. We'll give you added oxygen while we calibrate. You're not claustrophobic, are you?"

"I wasn't, until now." Marek was looking around at the interior. The dull strips, he now saw, were plastic-covered openings. Behind the plastic he saw lights, small whirring machines. The air became noticeably cooler.

"We're calibrating now," Gordon said. "Try not to move."

Suddenly, the individual strips around him began to rotate, the machines clicking. The strips spun faster and faster, then suddenly jerked to a stop.

"That's good. Feel all right?"

"It's like being inside a pepper mill," Marek said.

Gordon laughed. "Calibration is completed. The rest is dependent on exact timing, so the sequence is automatic. Just follow the instructions as you hear them. Okay?"

"Okay."

A click. Marek was alone.

A recorded voice said, "The scan sequence has begun. We are turning on lasers. Look straight ahead. And do not look up."

Instantly, the interior of the tube was a bright, glowing blue. The air itself seemed to be glowing.

"Lasers are polarizing the xenon gas, which is now being pumped into the compartment. Five seconds."

Marek thought, Xenon gas?

The bright blue color all around him increased in intensity. He looked down at his hand and could hardly see it for the shimmering air.

"We have reached xenon concentration. Now we will ask you to take a deep breath."

Marek thought, Take a deep breath? Of xenon?

"Hold your position without moving for thirty seconds. Ready? Stand still - eyes open - deep breath - hold it… Now!"

The strips suddenly began to spin wildly, then one by one, each strip started to jerk back and forth, almost as if it were looking, and sometimes had to go back for a second look. Each strip seemed to be moving individually. Marek had the uncanny sense of being examined by hundreds of eyes.

The recorded voice said, "Very still, please. Twenty seconds remaining."

All around him, the strips hummed and whirred. And then suddenly, they all stopped. Several seconds of silence. The machinery clicked. Now the strips began to move forward and back, as well as laterally.

"Very still, please. Ten seconds."

The strips began to spin in circles now, slowly synchronizing, until finally they were all rotating together as a unit. Then they stopped.

"The scan is completed. Thank you for your cooperation."

The blue light clicked off, and the hinged door hissed open. Marek stepped out.

In the adjacent room, Gordon sat in front of a computer console. The others had pulled up chairs around him.

"Most people," Gordon said, "don't realize that the ordinary hospital MRI works by changing the quantum state of atoms in your body - generally, the angular momentum of nuclear particles. Experience with MRIs tells us that changing your quantum state has no ill effect. In fact, you don't even notice it happening.

"But the ordinary MRI does this with a very powerful magnetic field - say, 1.5 tesla, about twenty-five thousand times as strong as the earth's magnetic field. We don't need that. We use superconducting quantum interference devices, or SQUIDs, that are so sensitive they can measure resonance just from the earth's magnetic field. We don't have any magnets in there."

Marek came into the room. "How do I look?" he said.

The image on the screen showed a translucent picture of Marek's limbs, in speckled red. "You're looking at the marrow, inside the long bones, the spine, and the skull," Gordon said. "Now it builds outward, by organ systems. Here's the bones" - they saw a complete skeleton-" and now we're adding muscles…"

Watching the organ systems appear, Stern said, "Your computer's incredibly fast."

"Oh, we've slowed this way down," Gordon said. "Otherwise you wouldn't be able to see it happening. The actual processing time is essentially zero."

Stern stared. "Zero?"

"Different world," Gordon said, nodding. "Old assumptions don't apply." He turned to the others. "Who's next?"

They walked down to the end of the corridor, to the room marked TRANSIT. Kate said, "Why did we just do all that?"

"We call it prepacking," Gordon said. "It enables us to transmit faster, because most of the information about you is already loaded into the machine. We just do a final scan for differences, and then we transmit."

They entered another elevator, and passed through another set of water-filled doors. "Okay," Gordon said. "Here we are."

They came out into an enormous, brightly lit, cavernous space. Sounds echoed. The air was cold. They were walking on a metal passageway, suspended a hundred feet above the floor. Looking down, Chris saw three semicircular water-filled walls, arranged to form a circle, with gaps between large enough for a person to walk through. Inside this outer wall were three smaller semicircles, forming a second wall. And inside the second wall was a third. Each successive semicircle was rotated so that the gaps never lined up, giving the whole thing a mazelike appearance.

In the center of the concentric circles was a space about twenty feet across. Here, half a dozen cagelike devices stood, each about the size of a phone booth. They were arranged in no particular pattern. They had dull-colored metal tops. White mist drifted across the enclosure. Tanks lay on the floor, and heavy black power cables snaked everywhere. It looked like a workroom. And in fact, some men were working on one of the cages.

"This is our transmission area," Gordon said. "Heavily shielded, as you can see. We're building a second area over there but it won't be ready for several months." He pointed across the cavernous space, where a second series of concentric walls were going up. These walls were clear; they hadn't been filled with water yet.

From the gangway, a cable elevator went down to the space in the center of the glass walls.

Marek said, "Can we go down there?"

"Not yet, no."

A technician looked up and waved. Gordon said, "How long until the burn check, Norm?"

"Couple of minutes. Gomez is on her way now."

"Okay." Gordon turned to the others. "Let's go up to the control booth to watch."

Bathed in deep blue light, the machines stood on a raised platform. They were dull gray in color and hummed softly. White vapor seeped along the floor, obscuring their bases. Two workmen in blue parkas were down on their hands and knees, working inside the opened base of one of them.

The machines were essentially open cylinders, with metal at the top and bottom. Each machine stood on a thick metal base. Three rods around the perimeter supported the metal roof.

Technicians were dragging a tangle of black cables down from an overhead grid and then attaching the cables to the roof of one machine, like gas station attendants filling a car.

The space between the base and the roof was completely empty. In fact, the whole machine seemed disappointingly plain. The rods were odd, triangular-shaped, and studded along their length. Pale blue smoke seemed to be coming from under the roof of the machine.

The machines didn't look like anything Kate had ever seen. She stared at the huge screens inside the narrow control room. Behind her, two technicians in shirtsleeves sat at two console desks. The screens in front of her gave the impression you were looking out a window, though in fact the control room was windowless.

"You are looking at the latest version of our CTC technology," Gordon said. "That stands for Closed Timelike Curve - the topology of space-time that we employ to go back. We've had to develop entirely new technologies to build these machines. What you see here is actually the sixth version, since the first working prototype was built three years ago."

Chris stared at the machines and said nothing. Kate Erickson was looking around the control room. Stern was anxious, rubbing his upper lip. Marek kept his eye on Stern.

"All the significant technology," Gordon continued, "is located in the base, including the indium-gallium-arsenide quantum memory, the computer lasers and the battery cells. The vaporizing lasers, of course, are in the metal strips. The dull-colored metal is niobium; pressure tanks are aluminum; storage elements are polymer."

A young woman with short dark red hair and a tough manner walked into the room. She wore a khaki shirt, shorts and boots; she looked as if she were dressed for a safari. "Gomez will be one of your aides when you go take your trip. She's going back right now to do what we call a `burn check.' She's already burned her navigation marker, fixing the target date, and now she's going to make sure it's accurate." He pushed the intercom. "Sue? Show us your nav marker, would you?"

The woman held up a white rectangular wafer, hardly larger than a postage stamp. She cupped it easily in her palm.

"She'll use that to go back. And to call the machine for the return - show us the button, would you, Sue?"

"It's a little hard to see," she said, turning the wafer on edge. "There's a tiny button here, you push it with your thumbnail. That calls the machine when you're ready to return."

"Thank you, Sue."

One of the technicians said, "Field buck."

They turned and looked. On his console, one screen showed an undulating three-dimensional surface with a jagged upswinging in the middle, like a mountain peak. "Nice one," Gordon said. "Classic." He explained to the others. "Because our field-sensing equipment is SQUID-based, we're able to detect extremely subtle discontinuities in the local magnetic field - we call them `field bucks.' We'll register them starting as early as two hours before an event. And in fact, these started about two hours ago. It means a machine is returning here."

"What machine?" Kate said.

"Sue's machine."

"But she hasn't left yet."

"I know," he said. "It doesn't seem to make sense. Quantum events are all counterintuitive."

"You're saying you get an indicator that she is returning before she has left?"

"Yes."

"Why?" Kate said.

Gordon sighed. "It's complicated. Actually, what we are seeing in the field is a probability function - the likelihood that a machine is going to return. We don't usually think about it that way. We just say it's coming back. But to be accurate, a field buck is really telling us that it is highly probable a machine is coming back."

Kate was shaking her head. "I don't get it."

Gordon said, "Let's just say that in the ordinary world, we have beliefs about cause and effect. Causes occur first, effects second. But that order of events does not always occur in the quantum world. Effects can be simultaneous with causes, and effects can precede causes. This is one minor example of that."

The woman, Gomez, stepped into one of the machines. She pushed the white wafer into a slot in the base in front of her. "She's just installed her nav marker, which guides the machine out and back."

"And how do you know you'll get back?" Stern said.

"A multiverse transfer," Gordon said, "creates a sort of potential energy, like a stretched spring that wants to snap back. So the machines can come home relatively easily. Outbound is the tricky part. That's what's encoded in the ceramic."

He leaned forward to press an intercom button. "Sue? How long are you gone?"

"I'll be a minute, maybe two."

"Okay. Synch elapsed."

Now the technicians began to talk, flipping switches at a console, looking at video readouts in front of them.

"Helium check."

"Read as full," a technician said, looking at her console.

"EMR check."

"Check."

"Stand by for laser alignment."

One of the technicians flipped a switch, and from the metal strips, a dense array of green lasers fired into the center of the machine, putting dozens of green spots on Gomez's face and body as she stood still, her eyes closed.

The bars began to revolve slowly. The woman in the center remained still. The lasers made green horizontal streaks over her body. Then the bars stopped.

"Lasers aligned."

Gordon said, "See you in a minute, Sue." He turned to the others. "Okay. Here we go."

The curved water shields around the cage began to glow a faint blue. Once again the machine began to rotate slowly. The woman in the center stood motionless; the machine moved around her.

The humming grew louder. The rotation increased in speed. The woman stood, calm and relaxed.

"For this trip," Gordon said, "she'll use up only a minute or two. But she actually has thirty-seven hours in her battery cells. That's the limit these machines can remain in a location without returning."

The bars were spinning swiftly. They now heard a rapid chattering sound, like a machine gun.

"That's the clearance check: infrared sensors verify the space around the machine. They won't proceed without two meters on all sides. They check both ways. It's a safety measure. We wouldn't want the machine emerging in the middle of a stone wall. All right. They're releasing xenon. Here she goes."

The humming was now very loud. The enclosure spun so rapidly, the metal strips were blurred. They could see the woman inside quite clearly.

They heard a recorded voice say, "Stand still - eyes open - deep breath - hold it… Now!"

From the top of the machine, a single ring descended, scanning quickly to her feet.

"Now watch closely. It's fast," Gordon said.

Kate saw deep violet lasers fire inward from all the bars toward the center. The woman inside seemed to glow white-hot for an instant, and then a burst of blinding white light flashed inside the machine. Kate closed her eyes, turned away. When she looked back again, there were spots in front of her eyes, and for a moment she couldn't see what had happened. Then she realized that the machine was smaller. It had pulled away from the cables at the top, which now dangled free.

Another laser flash.

The machine was smaller. The woman inside was smaller. She was now only about three feet high, and shrinking before their eyes in a series of bright laser flashes.

"Jesus," Stern said, watching. "What does that feel like?"

"Nothing," Gordon said. "You don't feel a thing. Nerve conduction time from skin to brain is on the order of a hundred milliseconds. Laser vaporization is five nanoseconds. You're long gone."

"But she's still there."

"No, she's not. She was gone in the first laser burst. The computer's just processing the data now. What you see is an artifact of compression stepping. The compression's about three to the minus two…"

There was another bright flash. The cage now shrank rapidly. It was three feet high, then two. Now it was close to the floor - less than a foot tall. The woman inside looked like a little doll in khakis.

"Minus four," Gordon said. There was another bright burst, near the floor. Now Kate couldn't see the cage at all.

"What happened to it?"

"It's there. Barely."

Another burst, this time just a pinpoint flash on the floor.

"Minus five."

The flashes came more quickly now, winking like a firefly, diminishing in strength. Gordon counted them out.

"And minus fourteen… Gone."

There were no more flashes.

Nothing.

The cage had vanished. The floor was dark rubber, empty.

Kate said, "We're supposed to do that?"

"It's not an unpleasant experience," Gordon said. "You're entirely conscious all the way down, which is something we can't explain. By the final data compressions, you are in very small domains - subatomic regions - and consciousness should not be possible. Yet it occurs. We think it may be an artifact, a hallucination that bridges the transition. If so, it's analogous to the phantom limb that amputees feel, even though the limb isn't there. This may be a kind of phantom brain. Of course, we are talking about very brief time periods, nanoseconds. But nobody understands consciousness anyway."

Kate was frowning. For some time now, she had been looking at what she saw as architecture, a kind of "form follows function" approach: wasn't it remarkable how these huge underground structures had concentric symmetry - slightly reminiscent of medieval castles - even though these modern structures had been built without any aesthetic plan at all. They had simply been built to solve a scientific problem. She found the resulting appearance fascinating.

But now that she was confronted by what these machines were actually used for, she struggled to make sense of what her eyes had just seen. And her architectural training was absolutely no help to her. "But this, uh, method of shrinking a person, it requires you to break her down-"

"No. We destroy her," Gordon said bluntly. "You have to destroy the original, so that it can be reconstructed at the other end. You can't have one without the other."

"So she actually died?"

"I wouldn't say that, no. You see-"

"But if you destroy the person at one end," Kate said, "don't they die?"

Gordon sighed. "It's difficult to think of this in traditional terms," he said. "Since you're instantaneously reconstructed at the very moment you are destroyed, how can you be said to have died? You haven't died. You've just moved somewhere else."

Stern felt certain - it was a visceral sense - that Gordon wasn't being entirely honest about this technology. Just looking at the curved water shields, at all the different machines standing on the floor, gave him the sense that there was quite a bit more that was being left unexplained. He tried to find it.

"So she is in the other universe now?" he asked.

"That's right."

"You transmitted her, and she arrived in the other universe? Just like a fax?"

"Exactly."

"But to rebuild her, you need a fax machine at the other end."

Gordon shook his head. "No, you don't," he said.

"Why not?"

"Because she's already there."

Stern frowned. "She's already there? How could that be?"

"At the moment of transmission, the person is already in the other universe. And therefore the person doesn't need to be rebuilt by us."

"Why?" Stern said.

"For now, just call it a characteristic of the multiverse. We can discuss it later if you like. I'm not sure everybody needs to be bothered with these details," he said, nodding to the others.

Stern thought, There is something more. Something he doesn't want to say to us. Stern looked back at the transmission area. Trying to find the odd detail, the thing that was out of place. Because he was sure that something here was out of place.

"Didn't you tell us that you've only sent a few people back?"

"That's right, yes."

"More than one at a time?"

"Almost never. Very rarely two."

"Then why do you have so many machines?" Stern said. "I count eight in there. Wouldn't two be enough?"

"You're just seeing the results of our research program," Gordon said. "We are constantly working to refine our design."

Gordon had answered smoothly enough, but Stern was certain he had seen something - some buried glint of uneasiness - in Gordon's eyes.

There is definitely something more.

"I would have thought," Stern said, "that you'd make refinements to the same machines."

Gordon shrugged again, but did not answer.

Definitely.

"What are those repairmen doing in there?" Stern said, still probing. He pointed to the men on their hands and knees, working on the base of one machine. "I mean by the machine in the corner. What exactly are they repairing?"

"David," Gordon began. "I really think-"

"Is this technology really safe?" Stern said.

Gordon sighed. "See for yourself."

On the big screen, a sequence of rapid flashes appeared on the floor of the transit room.

"Here she comes," Gordon said.

The flashes grew brighter. They heard the chattering sound again, first faintly, then louder. And then the cage was full-size; the humming died away; the ground mist swirled, and the woman climbed out, waving to the spectators.

Stern squinted at her. She appeared absolutely fine. Her appearance was identical to what it had been before.

Gordon looked at him. "Believe me," he said. "It's perfectly safe." He turned to the screen. "How'd it look back there, Sue?"

"Excellent," she said. "Transit site is on the north side of the river. Secluded spot, in the woods. And the weather's pretty good, for April." She glanced at her watch. "Get your team together, Dr. Gordon. I'm going to go burn the spare nav marker. Then let's go back there and pull that old guy out before somebody hurts him."

"Lie on your left side, please." Kate rolled over on the table and watched uneasily as an elderly man in a white lab coat raised what looked like a glue gun and placed it over her ear. "This will feel warm."

Warm? She felt a burning rush of heat in her ear. "What is that?"

"It's an organic polymer," the man said. "Nontoxic and nonallergenic. Give it eight seconds. All right, now please make chewing motions. We want a looser fit. Very good, keep chewing."

She heard him going down the line. Chris was on the table behind her, then Stern, then Marek. She heard the old man say, "Lie on your left side, please. This will feel warm… ."

Not long after, he was back. He had her turn over, and injected the hot polymer into her other ear Gordon was watching from the corner of the room. He said, "This is still a bit experimental but so far it works quite well. It's made of a polymer that begins to biodegrade after a week."

Later, the man had them stand up. He expertly popped the plastic implants out of their ears, moving down the line.

Kate said to Gordon, "My hearing is fine, I don't need a hearing aid."

"It's not a hearing aid," Gordon said.

Across the room, the man was drilling out the center of the plastic earpieces and inserting electronics. He worked surprisingly quickly. When the electronics were in place, he capped the hole with more plastic.

"It's a machine language translator and a radio mike. In case you need to understand what people are saying to you."

"But even if I understand what they're saying," she said, "how can I answer back?"

Marek nudged her. "Don't worry. I speak Occitan. And Middle French."

"Oh, that's good," she said sarcastically. "You going to teach it to me in the next fifteen minutes?" She was tense, she was about to be destroyed or vaporized or whatever the hell they did in that machine, and the words just popped out of her mouth.

Marek looked surprised. "No," he said seriously. "But if you stay with me, I will take care of you."

Something about his earnestness reassured her. He was such a straight arrow. She thought, He probably will take care of me. She felt herself relaxing.

Soon after, they were all fitted with flesh-colored plastic earpieces. "They're turned off now," Gordon said. "To turn them on, just tap your ear with your finger. Now, if you'll come over here…"

Gordon handed them each a small leather pouch. "We've been working on a first-aid kit; these are the prototypes. You're the first to enter the world, so you may have a use for them. You can keep them out of sight, under your clothing."

He opened one pouch and brought out a small aluminum canister about four inches high and an inch in diameter. It looked like a little shaving cream can. "This is the only defense we can provide you. It contains twelve doses of ethylene dihydride with a protein substrate. We can demonstrate for you with the cat, H.G. Where are you,