Timeline

She stopped.

Out of the corner of her eye, she'd caught a glimpse of something shiny. She turned, looked again. For a moment, she couldn't find it, but then she did.

It was a small piece of glass, protruding from the earth.

"Andre?" she said. "I think there's more."

The glass was thin, and perfectly clear. The edge was curved and smooth, almost modern in its quality. She brushed the dirt away with her fingertips and exposed one lens of an eyeglass.

It was a bifocal lens.

"What is it?" Andre said, coming back to her.

"You tell me."

He squinted at it, shone his light very near. His face was so close to the glass, his nose almost touched it. "Where did you find this?" He sounded concerned.

"Right here."

"Lying in the open, just like now?" His voice was tense, almost accusing.

"No, only the edge was exposed. I cleaned it off."

"How?"

"With my finger."

"So: you are telling me it was partly buried?" He sounded like he didn't believe her.

"Hey, what is this?"

"Just answer, please."

"No, Andre. It was mostly buried. Everything but that left edge was buried."

"I wish you had not touched it."

"I do, too, if I'd known you were going to act like - "

"This must be explained," he said. "Turn around."

"What?"

"Turn around." He took her by the shoulder, turned her roughly, so she was facing away from him.

"Jesus." She glanced over her shoulder to see what he was doing. He held his light very close to her backpack and moved over the surface slowly, examining it minutely, then down to her shorts. "Uh, are you going to tell me - "

"Be quiet, please."

It was a full minute before he finished. "The lower left zip pocket of your pack is open. Did you open it?"

"No."

"Then it has been open all the time? Ever since you put the pack on?"

"I guess. . . ."

"Did you brush against the wall at any time?"

"I don't think so." She had been careful about it, because she hadn't wanted the wall to break loose.

"Are you sure?" he said.

"For Christ's sake. No, Andre, I'm not sure."

"All right. Now you check me." He handed her his light, and turned his back to her.

"Check you how?" she said.

"That glass is contamination," he said. "We have to explain how it got here. Look to see if any part of my pack is open."

She looked. Nothing was.

"Did you look carefully?"

"Yes, I looked carefully," she said, annoyed.

"I think you didn't take enough time."

"Andre. I did."

Marek stared at the earthen mound in front of them. Small pebbles trickled down as he watched. "It could have fallen from one of our packs and then been covered. . . ."

"Yes, I guess it could."

"If you could clean it with a fingertip, it was not tightly buried. . . ."

"No, no. Very loose."

"All right. Then somehow, that is the explanation."

"What is?"

"Somehow, we brought this lens in with us, and while we were working on the oilskin documents, it fell from the pack, and was covered by dirt. Then you saw it, and cleaned it. It is the only explanation."

"Okay. . . ."

He took out a camera, photographed the glass several times from different distances  -  very close, then progressively farther back. Only then did he bring out a plastic baggie, lift the glass carefully with tweezers, and drop it into the bag. He brought out a small roll of bubble wrap, encased the bag, sealed it all with tape, and handed the bundle to her. "You bring it out. Please be careful." He seemed more relaxed. He was being nicer to her.

"Okay," she said. They climbed the dirt slope again, heading back outside.

They were greeted by cheers from the undergraduates, and the oilskin package was handed over to Elsie, who quickly took it back to the farmhouse. Everyone was laughing and smiling, except Chang and Chris Hughes. They were wearing headsets, and had heard everything inside the cave. They looked gloomy and upset.

Site contamination was extremely serious, and they all knew it. Because it implied sloppy excavation technique, it called into question any other, legitimate discoveries made by the team. A typical instance was a minor scandal at Les Eyzies the year before.

Les Eyzies was a Paleolithic site, a habitation of early man beneath a cliff ledge. The archaeologists had been digging at a level that dated to 320,000 B.P., when one of them found a half-buried condom. It was still in its metallic wrapper, and nobody thought for a moment that it belonged at that level. But the fact that it had been found there  -  half-buried  -  suggested that they were not being careful in their technique. It caused a near panic among the team, which persisted even after a graduate student was sent back to Paris in disgrace.

"Where is this glass lens?" Chris said to Marek.

"Kate has it."

She gave it to Chris. While everyone else was cheering, he turned away, unwrapped the package, and held the baggie up to the light.

"Definitely modern," he said. He shook his head unhappily. "I'll check it out. Just make sure you include it in the site report."

Marek said he would.

Then Rick Chang turned away and clapped his hands. "All right, everybody. Excitement's over. Back to work!"

In the afternoon, Marek scheduled archery practice. The undergraduates were amused by it, and they never missed a session; recently Kate had taken it up, as well. The target today was a straw-filled scarecrow, set about fifty yards away. The kids were all lined up, holding their bows, and Marek strode down behind them.

"To kill a man," he said, "you have to remember: he is almost certainly wearing plate armor on his chest. He's less likely to have armor on his head and neck, or on his legs. So to kill him, you must shoot him in the head, or on the side of his torso, where the plates don't cover."

Kate listened to Marek, amused. Andre took everything so seriously. To kill a man. As if he really meant it. Standing in the yellow afternoon sunlight of southern France, hearing the distant honk of cars on the road, the idea seemed slightly absurd.

"But if you want to stop a man," Marek continued, "then shoot him in the leg. He'll go right down. Today we'll use the fifty-pound bows."

Fifty pounds referred to the draw weight, what was needed to pull the string back. The bows were certainly heavy, and difficult to draw. The arrows were almost three feet long. Many of the kids had trouble with it, especially at first. Marek usually finished each practice session with some weight lifting, to build up their muscles.

Marek himself could draw a hundred-pound bow. Although it was difficult to believe, he insisted that this was the size of actual fourteenth-century weapons  -  far beyond what any of them could use.

"All right," Marek said, "nock your arrows, aim, and loose them, please." Arrows flew through the air. "No, no, no, David, don't pull until you tremble. Maintain control. Carl, look at your stance. Bob, too high. Deanna, remember your fingers. Rick, that was much better. All right, here we go again, nock your arrows, aim, and . . . loose them!"

It was late in the afternoon when Stern called Marek on the radio, and asked him to come to the farmhouse. He said he had good news. Marek found him at the microscope, examining the lens.

"What is it?"

"Here. Look for yourself." He stepped aside, and Marek looked. He saw the lens, and the sharp line of the bifocal cut. Here and there, the lens was lightly spotted with white circles, as if from bacteria.

"What am I supposed to see?" Marek said.

"Left edge."

He moved the stage, bringing the left edge into view. Refracted in the light, the edge looked very white. Then he noticed that the whiteness spilled over the edge, onto the surface of the lens itself.

"That's bacteria growing on the lens," Stern said. "It's like rock varnish."

Rock varnish was the term for the patina of bacteria and mold that grew on the underside of rocks. Because it was organic, rock varnish could be dated.

"Can this be dated?" Marek said.

"It could," Stern said, "if there was enough of it for a C-14 run. But I can tell you now, there isn't. You can't get a decent date from that amount. There isn't any use trying."

"So?"

"The point is, that was the exposed edge of the lens, right? The edge that Kate said was sticking out of the earth?"

"Right. . . ."

"So it's old, Andre. I don't know how old, but it's not site contamination. Rick is looking at all the bones that were exposed today, and he thinks some of them are later than our period, eighteenth century, maybe even nineteenth century. Which means one of them could have been wearing bifocals."

"I don't know. This lens looks pretty sharply done. . . ."

"Doesn't mean it's new," Stern said. "They've had good grinding techniques for two hundred years. I'm arranging for this lens to be checked by an optics guy back in New Haven. I've asked Elsie to jump ahead and do the oilskin documents, just to see if there's anything unusual there. In the meantime, I think we can all ease up."

"That's good news," Marek said, grinning.

"I thought you'd want to know. See you at dinner."

They had arranged to have dinner in the old town square of Domme, a village on top of a cliff a few miles from their site. By nightfall, Chris, grumpy all day, had recovered from his bad mood and was looking forward to dinner. He wondered if Marek had heard from the Professor, and if not, what they were going to do about it. He had a sense of expectancy.

His good mood vanished when he arrived to find the stockbroker couples again, sitting at their table. Apparently they'd been invited for a second night. Chris was about to turn around and leave, but Kate got up and quickly put her arm around his waist, and steered him toward the table.

"I'd rather not," he said in a low voice. "I can't stand these people." But then she gave him a little hug, and eased him into a chair. He saw that the stockbrokers must be buying the wine tonight  -  Chateau Lafite-Rothschild '95, easily two thousand francs a bottle.

And he thought, What the hell.

"Well, this is a charming town," one of the women was saying. "We went and saw the walls around the outside. They go on for quite a distance. High, too. And that very pretty gate coming into town, you know, with the two round towers on either side."

Kate nodded. "It's sort of ironic," she said, "that a lot of the villages that we find so charming now were actually the shopping malls of the fourteenth century."

"Shopping malls? How do you mean?" the woman asked.

At that moment, Marek's radio, clipped to his belt, crackled with static.

"Andre? Are you there?"

It was Elsie. She never came to dinner with the others, but worked late on her cataloging. Marek held up the radio. "Yes, Elsie."

"I just found something very weird, here."

"Yes. . . ."

"Would you ask David to come over? I need his help testing. But I'm telling you guys  -  if this is a joke, I don't appreciate it."

With a click, the radio went dead.

"Elsie?"

No answer.

Marek looked around the table. "Anybody play a joke on her?"

They all shook their heads no.

Chris Hughes said, "Maybe she's cracking up. It wouldn't surprise me, all those hours staring at parchment."

"I'll see what she wants," David Stern said, getting up from the table. He headed off into the darkness.

Chris thought of going with him, but Kate looked at him quickly, and gave him a smile. So he eased back in his seat and reached for his wine.

"You were saying  -  these towns were like shopping malls?"

"A lot of them were, yes," Kate Erickson said. "These towns were speculative ventures to make money for land developers. Just like shopping malls today. And like malls, they were all built on a similar pattern."

She turned in her chair and pointed to the Domme town square behind them. "See the covered wooden market in the center of the town square? You'll find similar covered markets in lots of towns around here. It means the town is a bastide, a new, fortified village. Nearly a thousand bastide towns were built in France during the fourteenth century. Some of them were built to hold territory. But many of them were built simply to make money."

That got the attention of the stock pickers.

One of the men looked up sharply and said, "Wait a minute. How does building a village make anybody money?"

Kate smiled. "Fourteenth-century economics," she said. "It worked like this. Let's say you're a nobleman who owns a lot of land. Fourteenth-century France is mostly forest, which means that your land is mostly forest, inhabited by wolves. Maybe you have a few farmers here and there who pay you some measly rents. But that's no way to get rich. And because you're a nobleman, you're always desperately in need of money, to fight wars and to entertain in the lavish style that's expected of you.

"So what can you do to increase the income from your lands? You build a new town. You attract people to live in your new town by offering them special tax breaks, special liberties spelled out in the town charter. Basically, you free the townspeople from feudal obligations."

"Why do you give them these breaks?" one of the men said.

"Because pretty soon you'll have merchants and markets in the town, and the taxes and fees generate much more money for you. You charge for everything. For the use of the road to come to the town. For the right to enter the town walls. For the right to set up a stall in the market. For the cost of soldiers to keep order. For providing moneylenders to the market."

"Not bad," one of the men said.

"Not bad at all. And in addition, you take a percentage of everything that's sold in the market."

"Really? What percentage?"

"It depended on the place, and the particular merchandise. In general, one to five percent. So the market is really the reason for the town. You can see it clearly, in the way the town is laid out. Look at the church over there," she said, pointing off to the side. "In earlier centuries, the church was the center of the town. People went to Mass at least once a day. All life revolved around the church. But here in Domme, the church is off to one side. The market is now the center of town."

"So all the money comes from the market?"

"Not entirely, because the fortified town offers protection for the area, which means farmers will clear the nearby land and start new farms. So you increase your farming rents, as well. All in all, a new town was a reliable investment. Which is why so many of these towns were built."

"Is that the only reason the towns were built?"

"No, many were built for military considerations as - "

Marek's radio crackled. It was Elsie again. "Andre?"

"Yes," Marek said.

"You better get over here right away. Because I don't know how to handle this."

"Why? What is it?"

"Just come. Now."

The generator chugged loudly, and the farmhouse seemed brilliantly lit in the dark field, under a sky of stars.

They all crowded into the farmhouse. Elsie was sitting at her desk in the center, staring at them. Her eyes seemed distant.

"Elsie?"

"It's impossible," she said.

"What's impossible? What happened here?"

Marek looked over at David Stern, but he was still working at some analysis in the corner of the room.

Elsie sighed. "I don't know, I don't know. . . ."

"Well," Marek said, "start at the beginning."

"Okay," she said. "The beginning." She stood up and crossed the room, where she pointed to a stack of parchments resting on a piece of plastic tarp on the floor. "This is the beginning. The document bundle I designated M-031, dug up from the monastery earlier today. David asked me to do it as soon as possible."

Nobody said anything. They just watched her.

"Okay," she said. "I've been going through the bundle. This is how I do it. I take about ten parchments at a time and bring them over here to my desk." She brought ten over. "Now, I sit down at the desk, and I go through them, one by one. Then, after I've summarized the contents of one sheet, and entered the summary into the computer, I take the sheet to be photographed, over here." She went to the next table, slipped a parchment under the camera.

Marek said, "We're familiar with - "

"No, you're not," she said sharply. "You're not familiar at all." Elsie went back to her table, took the next parchment off the stack. "Okay. So I go through them one by one. This particular stack consists of all kinds of documents: bills, copies of letters, replies to orders from the bishop, records of crop yields, lists of monastery assets. All dating from about the year 1357."

She took the parchments from the stack, one after the other.

"And then"  -  she removed the last one  -  "I see this."

They stared.

Nobody said anything.

The parchment was identical in size to the others in the stack, but instead of dense writing in Latin or Old French, this one had only two words, scrawled in plain English:

HELP ME

4/7/1357

"In case you're wondering," she said, "that's the Professor's handwriting."

The room was silent. No one moved or shifted. They all just stared in complete silence.

Marek was thinking very fast, running through the possibilities. Because of his detailed, encyclopedic knowledge of the medieval period, for many years he had served as an outside consultant on medieval artifacts to the Metropolitan Museum of Art in New York. As a result, Marek had considerable experience with fakes of all kinds. It was true that he was rarely shown faked documents from the medieval period  -  the fakes were usually precious stones set in a bracelet that was ten years old, or a suit of armor that turned out to have been made in Brooklyn  -  but his experience had given him a clear way to think it through.

Marek said, "Okay. Begin at the beginning. Are you sure that's his handwriting?"

"Yes," Elsie said. "Without question."

"How do you know?"

She sniffed. "I'm a graphologist, Andre. But here. See for yourself."

She brought out a note that Johnston had scrawled a few days earlier, a note written in block letters, attached to a bill: "PLS CHK THIS CHARGE." She set it beside the parchment signature. "Block letters are actually easier to analyze. His H, for example, has a faint diagonal beneath. He draws one vertical line, lifts his pen, draws the second vertical, then drags his pen back to draw the crossbar, making the diagonal below. Or look at the P. He makes a downward stroke, then goes up and back to position to make the semicircle. Or the E, which he draws as an L and then zigzags back up to make the two added lines. There's no question. It's his handwriting."

"Someone couldn't have forged it?"

"No. Forgery, you have pen lifts and other signs. This writing is his."

Kate said, "Would he play a joke on us?"

"If he did, it isn't funny."

"What about this parchment it's written on?" Marek said. "Is it as old as the other sheets in the stack?"

"Yes," David Stern said, coming over. "Short of carbon dating, I'd say yes  -  it's the same age as the others."

Marek thought: How can that be? He said, "Are you sure? This parchment looks different. The surface looks rougher to me."

"It is rougher," Stern said. "Because it's been poorly scraped. Parchment was valuable material in medieval times. Generally it was used, scraped clean, and then used again. But if we look at this parchment under ultra-violet. . . . Would somebody get the lights?" Kate turned them off, and in the darkness Stern swung a purple lamp over the table.

Marek immediately saw more writing, faint but clearly there on the parchment.

"This was originally a bill for lodging," Elsie said. "It's been scraped clean, quickly and crudely, as if somebody was in a hurry."

Chris said, "Are you saying the Professor scraped it?"

"I have no idea who scraped it. But it's not expertly done."

"All right," Marek said. "There's one definitive way to decide this, once and for all." He turned to Stern. "What about the ink, David? Is it genuine?"

Stern hesitated. "I'm not sure."

"Not sure? Why not?"

"Chemically speaking," Stern said, "it's exactly what you'd expect: iron in the form of ferrous oxide, mixed with gall as an organic binder. Some added carbon for blackness, and five percent sucrose. In those days, they used sugar to give the inks a shiny surface. So it's ordinary iron-gall ink, correct for the period. But that in itself doesn't mean much."

"Right." Stern was saying it could be faked.

"So I ran gall and iron titers," Stern said, "which I usually do in questionable cases. They tell us the exact amounts present in the ink. The titers indicate that this particular ink is similar but not identical to the ink on the other documents."

"Similar but not identical," Marek said. "How similar?"

"As you know, medieval inks were mixed by hand before use, because they didn't keep. Gall is organic  -  it's the ground-up nuts of an oak tree  -  which means the inks would eventually go bad. Sometimes they added wine to the ink as a preservative. Anyway, there's usually a fairly large variation in gall and iron content from one document to another. You find as much as twenty or thirty percent difference between documents. It's reliable enough that we can use these percentages to tell if two documents were written on the same day, from the same ink supply. This particular ink is about twenty-nine percent different from the documents on either side of it."

"Meaningless," Marek said. "Those numbers don't confirm either authenticity or forgery. Did you do a spectrographic analysis?"

"Yes. Just finished it. Here's the spectra for three documents, with the Professor's in the middle." Three lines, a series of spikes and dips. "Again, similar but not identical."

"Not that similar," Marek said, looking at the pattern of spikes. "Because along with the percentage difference in iron content, you've got lots of trace elements in the Professor's ink, including  -  what's this spike, for instance?"

"Chromium."

Marek sighed. "Which means it's modern."

"Not necessarily, no."

"There's no chromium in the inks before and after."

"That's true. But chromium is found in manuscript inks. Fairly commonly."

"Is there chromium in this valley?"

"No," Stern said, "but chromium was imported all over Europe, because it was used for fabric dyes as well as inks."

"But what about all these other contaminants?" Marek said, pointing to the other spikes. He shook his head. "I'm sorry. I'm just not buying this."

Stern said, "I agree. This has to be a joke."

"But we're not going to know for sure without a carbon date," Marek said. Carbon-14 would enable them to date both ink and parchment within about fifty years. That would be good enough to settle the question of forgery.

"I'd also like to do thermoluminescence, and maybe a laser activation while we're at it," Stern said.

"You can't do that here."

"No, I'll take it over to Les Eyzies." Les Eyzies, the town in the next valley that was the center of prehistoric studies in southern France, had a well-equipped lab that did carbon-14 and potassium-argon dating, as well as neutron activation and other difficult tests. The field results weren't as accurate as the labs in Paris or Toulouse, but scientists could get an answer in a few hours.

"Any chance you can run it tonight?" Marek said.

"I'll try."

Chris came back to join the group; he had been telephoning the Professor on a cell phone. "Nothing," he said. "I just got his voicemail."

"All right," Marek said. "There's nothing more we can do right now. I assume this message is a bizarre joke. I can't imagine who played it on us  -  but somebody did. Tomorrow we'll run carbon and date the message. I have no doubt it will prove to be recent. And with all due respect to Elsie, it's probably a forgery."

Elsie started to sputter.

"But in any case," Marek continued, "the Professor is due to call in tomorrow, and we'll ask him. In the meantime, I suggest we all go to bed and get a good night's rest."

In the farmhouse, Marek closed the door softly behind him before turning on the lights. Then he looked around.

The room was immaculate, as he would have expected. It had the tidiness of a monk's cell. Beside the bed stood five or six research papers, neatly stacked. On a desk to the right, more research papers sat beside a closed laptop computer. The desk had a drawer, which he opened and rummaged through quickly.

But he didn't find what he was looking for.

He went next to the armoire. The Professor's clothes were neatly arranged inside, with space between each hanging garment. Marek went from one to the next, patting the pockets, but he still did not find it. Perhaps it wasn't here, he thought. Perhaps he had taken it with him to New Mexico.

There was a bureau opposite the door. He opened the top drawer: coins in a small shallow dish, American dollar bills wrapped in a rubber band, and a few personal objects, including a knife, a pen and a spare watch  -  nothing out of the ordinary.

Then he saw a plastic case, tucked over to one side.

He brought the case out, opened it up. The case contained eyeglasses. He set the glasses out on the counter.

The lenses were bifocals, oval in shape.

He reached into his shirt pocket and brought out a plastic bag. He heard a creak behind him, and turned to see Kate Erickson coming in through the door.

"Going through his underwear?" she said, raising her eyebrows. "I saw the light under the door. So I had a look."

"Without knocking?" Marek said.

"What are you doing in here?" she said. Then she saw the plastic. "Is that what I think it is?"

"Yes."

Marek took the single bifocal lens out of the plastic bag, holding it with a pair of tweezers, and placed it on top of the bureau, beside the Professor's eyeglasses.

"Not identical," she said. "But I'd say the lens is his."

"So would I."

"But isn't that what you always thought? I mean, he's the only one on the site who wears bifocals. The contamination has to be from his eyeglasses."

"But there isn't any contamination," Marek said. "This lens is old."

"What?"

"David says that white edge is bacterial growth. This lens is not modern, Kate. It's old."

She looked closely. "It can't be," she said. "Look at the way the lenses are cut. It's the same in the Professor's glasses and this lens. It must be modern."

"I know, but David insists it's old."

"How old?"

"He can't tell."

"He can't date it?"

Marek shook his head. "Not enough organic material."

"So in that case," she said, "you came to his room because . . ." She paused, staring at the eyeglasses, then at him. She frowned. "I thought you said that signature was a forgery, Andre."

"I did, yes."

"But you also asked if David could do the carbon test tonight, didn't you."

"Yes. . . ."

"And then you came here, with the glass, because you're worried. . . ." She shook her head as if to clear it. "About what? What do you think is going on?"

Marek looked at her. "I have absolutely no idea. Nothing makes sense."

"But you're worried."

"Yes," Marek said. "I'm worried."

The following day dawned bright and hot, a glaring sun beneath a cloudless sky. The Professor didn't call in the morning. Marek called him twice, but always got his voicemail: "Leave me a message, and I'll call you back."

Nor was there any word from Stern. When they called the lab at Les Eyzies they were told he was busy. A frustrated technician said, "He is repeating the tests again! Three times now!"

Why? Marek wondered. He considered going over to Les Eyzies to see for himself  -  it was just a short drive  -  but decided to stay at the storehouse in case the Professor called.

He never called.

In the middle of the morning, Elsie said, "Huh."

"What?"

She was looking at another piece of parchment. "This was the document on the stack right before the Professor's," she said.

Marek came over. "What about it?"

"It looks like there are ink spots from the Professor's pen. See, here, and here?"

Marek shrugged. "He was probably looking at this right before he wrote his note."

"But they're in the margin," she said, "almost like a notation."

"Notation to what?" he said. "What's the document about?"

"It's a piece of natural history," she said. "A description of an underground river by one of the monks. Says you have to be cautious at various points, marked off in paces, so on and so forth."

"An underground river. . . ." Marek wasn't interested. The monks were the scholars of the region, and they often wrote little essays on local geography, or carpentry, the proper time to prune orchard trees, how best to store grain in winter, and so on. They were curiosities, and often wrong.

" 'Marcellus has the key,' " she said, reading the text. "Wonder what that means. It's right where the Professor put his marks. Then . . . something about . . . giant feet . . . no . . . the giant's feet? . . . The feet of the giant? . . . And it says vivix, which is Latin for . . . let me see. . . . That's a new one. . . ."

She consulted a dictionary.

Restless, Marek went outside and paced up and down. He was edgy, nervous.

"That's odd," she said, "there is no word vivix. At least not in this dictionary." She made a note, in her methodical way.

Marek sighed.

The hours crawled by.

The Professor never called.

Finally it was three o'clock; the students were wandering up to the big tent for their afternoon break. Marek stood in the door and watched them. They seemed carefree, laughing, punching each other, making jokes.

The phone rang. He immediately turned back. Elsie picked it up. He heard her say, "Yes, he's here with me right now. . . ."

He hurried into her room. "The Professor?"

She was shaking her head. "No. It's someone from ITC." And she handed him the phone.

"This is Andre Marek speaking," he said.

"Oh yes. Please hold, Mr. Marek. I know Mr. Doniger is eager to speak to you."

"He is?"

"Yes. We've been trying to reach you for several hours. Please hold while I find him for you."

A long pause. Some classical music played. Marek put his hand over the phone and said to Elsie, "It's Doniger."

"Hey," she said. "You must rate. The big cheese himself."

"Why is Doniger calling me?"

Five minutes later, he was still waiting on hold, when Stern walked into the room, shaking his head. "You're not going to believe this."

"Yes? What?" Marek said, holding the phone.

Stern just handed him a sheet of paper. It said:

638 �� 47 BP

"What is this supposed to be?" Marek said.

"The date on the ink."

"What are you talking about?"

"The ink on that parchment," Stern said. "It's six hundred and thirty-eight years old, plus or minus forty-seven years."

"What?" Marek said.

"That's right. The ink has a date of A.D. 1361."

"What?"

"I know, I know," Stern said. "But we ran the test three times. There's no question about it. If the Professor really wrote that, he wrote it six hundred years ago." Marek flipped the paper over. On the other side, it said:

AD 1361 �� 47 years

On the phone, the music ended with a click, and a taut voice said, "This is Bob Doniger. Mr. Marek?"

"Yes," Marek said.

"You may not remember, but we met a couple of years ago, when I visited the site."

"I remember very well," Marek said.

"I'm calling about Professor Johnston. We are very concerned for his safety."

"Is he missing?"

"No, he's not. We know exactly where he is."

Something in his tone sent a shiver down Marek's spine. Marek said, "Then can I speak to him?"

"Not at the moment, I'm afraid."

"Is the Professor in danger?"

"It's difficult to say. I hope not. But we're going to need the help of you and your group. I've already sent the plane to get you."

Marek said, "Mr. Doniger, we seem to have a message from Professor Johnston that is six hundred years - "

"Not on a cell phone," Doniger said, cutting him off. But Marek noticed that he didn't seem at all surprised. "It's three o'clock now in France, is that right?"

"Just after, yes."

"All right," Doniger said. "Pick the three members of your team who know the Dordogne region best. Drive to the airport at Bergerac. Don't bother to pack. We'll supply everything when you get here. The plane lands at six p.m. your time, and will bring you back to New Mexico. Is that clear?"

"Yes, but - "

"I'll see you then."

And Doniger hung up.

David Stern looked at Marek. "What was that all about?" he said.

Marek said, "Go get your passport."

"What?"

"Go get your passport. Then come back with the car."

"We going somewhere?"

"Yes, we are," Marek said.

And he reached for his radio.

Kate Erickson looked down from the ramparts of La Roque Castle into the inner bailey, the broad grassy center of the castle, twenty feet below. The grass was swarming with tourists of a dozen nationalities, all in bright clothes and shorts. Cameras clicking in every direction.

Beneath her, she heard a young girl say, "Another castle. Why do we have to go to all these stupid castles, Mom?"

The mother said, "Because Daddy is interested."

"But they're all the same, Mom."

"I know, dear. . . ."

The father, a short distance away, was standing inside low walls that outlined a former room. "And this," he announced to his family, "was the great hall."

Looking down, Kate saw at once that it wasn't. The man was standing inside the remains of the kitchen. It was obvious from the three ovens still visible in the wall to the left. And the stone sluice that had brought water could be seen just behind the man as he spoke.

"What happened in the great hall?" his daughter asked.

"This is where they held their banquets, and where visiting knights paid homage to the king."

Kate sighed. There was no evidence a king had ever been to La Roque. On the contrary, documents indicated that it had always been a private castle, built in the eleventh century by someone named Armand de Clery, and later heavily rebuilt early in the fourteenth century, with another ring of outer walls, and additional drawbridges. That added work was done by a knight named Fran?ois le Gros, or Francis the Fat, around 1302.

Despite his name, Fran?ois was an English knight, and he built La Roque in the new English style of castles, established by Edward I. The Edwardian castles were large, with spacious inner courtyards and pleasant quarters for the lord. This suited Fran?ois, who by all accounts had an artistic temperament, a lazy disposition, and a propensity for money troubles. Fran?ois was forced to mortgage his castle, and later to sell it outright. During the Hundred Years War, La Roque was controlled by a succession of knights. But the fortifications held: the castle was never captured in battle, only in commercial transactions.

As for the great hall, she saw it was off to the left, badly ruined, but clearly indicating the outlines of a much larger room, almost a hundred feet long. The monumental fireplace  -  nine feet high and twelve feet wide  -  was still visible. Kate knew that any great hall of this size would have had stone walls and a timber roof. And yes, as she looked, she saw notches in the stone high up, to hold the big horizontal timbers. Then there would have been cross-bracing above that, to support the roof.

A British tour group squeezed past her on the narrow ramparts. She heard the guide say, "These ramparts were built by Sir Francis the Bad in 1363. Francis was a thoroughly nasty piece of work. He liked to torture men and women, and even children, in his vast dungeons. Now if you look to the left, you will see Lover's Leap, where Madame de Renaud fell to her death in 1292, disgraced because she was pregnant by her husband's stable boy. But it is disputed whether she fell or was pushed by her outraged spouse. . . ."

Kate sighed. Where did they come up with this stuff? She turned to her sketchbook notes, where she was recording the outlines of the walls. This castle, too, had its secret passages. But Francis the Fat was a skilled architect. His passages were mostly for defense. One passage ran from the ramparts down behind the far wall of the great hall, past the rear of the fireplace. Another passage followed the battlements on the south ramparts.

But the most important passage still eluded her. According to the fourteenth-century writer Froissart, the castle of La Roque had never been taken by siege because its attackers could never find the secret passage that permitted food and water to be brought to the castle. It was rumored that this secret passage was linked to the network of caves in the limestone rock below the castle; also that it ran some distance, ending in a concealed opening in the cliffs.

Somewhere.

The easiest way to find it now would be to locate where it ended inside the castle and to follow it back. But to find that opening, she would need technical help. Probably the best thing would be ground radar. But to do that, she'd need the castle empty. It was closed on Mondays; they might do it next Monday, if -

Her radio crackled. "Kate?"

It was Marek.

She held the radio to her face, pressed the button. "Yes, this is Kate."

"Come back to the farmhouse now. It's an emergency."

And he clicked off.

Nine feet underwater, Chris Hughes heard the gurgling hiss of his regulator as he adjusted the tether that held him in place against the current of the Dordogne. The water clarity was not bad today, about twelve feet, and he was able to see the entire large pylon of the fortified mill bridge, at the water's edge. The pylon ended in a jumble of large cut rocks that ran in a straight line across the river. These rocks were the remains of the former bridge span.

Chris moved along this line, examining the rocks slowly. He was looking for grooves or notches that would help him determine where timbers had been used. From time to time, he tried to turn one rock over, but it was very difficult underwater because he could get no leverage.

On the surface above, he had a plastic float with a red-striped diver's flag. It was there to protect him from the vacationing kayakers. At least, that was the idea.

He felt a sudden jerk, yanking him away from the bottom. He broke surface and bumped his head against the yellow hull of a kayak. The rider was holding the plastic float, shouting at him in what sounded like German.

Chris pulled his mouthpiece out and said, "Just leave that alone, will you?"

He was answered in rapid German. The kayaker was pointing irritably toward the shore.

"Listen, pal, I don't know what you're - "

The man kept shouting and pointing toward the shore, his finger stabbing the air.

Chris looked back.

One of the students was standing on the shore, holding a radio in his hand. He was shouting. It took Chris a moment to understand. "Marek wants you back to the farmhouse. Now."

"Jesus, how about in half an hour, when I finish - "

"He says now."

Dark clouds hung over the distant mesas, and it looked like there would be rain. In his office, Doniger hung up the phone and said, "They've agreed to come."

"Good," Diane Kramer said. She was standing facing him, her back to the mountains. "We need their help."

"Unfortunately," Doniger said, "we do." He got up from his desk and began to pace. He was always restless when he was thinking hard.

"I just don't understand how we lost the Professor in the first place," Kramer said. "He must have stepped into the world. You told him not to do it. You told him not to go in the first place. And he must have stepped into the world."

"We don't know what happened," Doniger said. "We have no damn idea."

"Except that he wrote a message," Kramer said.

"Yes. According to Kastner. When did you talk to her?"

"Late yesterday," Kramer said. "She called me as soon as she knew. She's been a very reliable connection for us, and she - "

"Never mind," Doniger said, waving his hand irritably. "It's not core."

That was the expression he always used when he thought something was irrelevant. Kramer said, "What's core?"

"Getting him back," Doniger said. "It is essential that we get that man back. That is core."

"No question," Kramer said. "Essential."

"Personally, I thought the old fart was an asshole," Doniger said. "But if we don't get him back, it's a publicity nightmare."

"Yes. A nightmare."

"But I can deal with it," Doniger said.

"You can deal with it, I'm sure."

Over the years, Kramer had fallen into the habit of repeating whatever Doniger said when he was in one of his "pacing moods." To an outsider, it looked like sycophancy, but Doniger found it useful. Frequently, when Doniger heard her say it back, he would disagree. Kramer understood that in this process, she was just a bystander. It might look like a conversation between two people, but it wasn't. Doniger was talking only to himself.

"The problem," Doniger said, "is that we're increasing the number of outsiders who know about the technology, but we're not getting a commensurate return. For all we know, those students won't be able to get him back, either."

"Their chances are better."

"That's a presumption." He paced. "It's weak."

"I agree, Bob. Weak."

"And the search team you sent back? Who did you send?"

"Gomez and Baretto. They didn't see the Professor anywhere."

"How long were they there?"

"I believe about an hour."

"They didn't step into the world?"

Kramer shook her head. "Why take the risk? There's no point. They're a couple of ex-marines, Bob. They wouldn't know where to look even if they did step in. They wouldn't even know what to be afraid of. It's completely different back there."

"But these graduate students may know where to look."

"That's the idea," Kramer said.

Distant thunder rumbled. The first fat drops of rain streaked the office windows. Doniger stared at the rain. "What if we lose the graduate students, too?"

"A publicity nightmare."

"Maybe," Doniger said. "But we have to prepare for the possibility."

The jet engines whined as the Gulfstream V rolled toward them, "ITC" in big silver letters on the tail. The stairs lowered, and a uniformed flight attendant rolled out a strip of red carpet at the bottom of the stairs.

The graduate students stared.

"No kidding," Chris Hughes said. "There really is a red carpet."

"Let's go," Marek said. He threw his backpack over his shoulder and led them aboard.

Marek had refused to answer their questions, pleading ignorance. He told them the results of the carbon dating. He told them he couldn't explain it. He told them that ITC wanted them to come to help the Professor, and that it was urgent. He didn't say any more. And he noticed that Stern, too, was keeping silent.

Inside, the plane was all gray and silver. The flight attendant asked them what they wanted to drink. All this luxury contrasted with the tough-looking man with cropped gray hair who came forward to greet them. Although the man wore a business suit, Marek detected a military manner as he shook hands with each of them.

"My name's Gordon," he said. "Vice president at ITC. Welcome aboard. Flying time to New Mexico is nine hours, forty minutes. Better fasten your seat belts."

They dropped into seats, already feeling the aircraft begin to move on the runway. Moments later, the engines roared, and Marek looked out the window to see the French countryside fall away beneath them.

It could be worse, Gordon thought, sitting at the back of the plane and looking at the group. True, they were academics. They were a little befuddled. And there was no coordination, no team feeling among them.

But on the other hand, they all seemed to be in decent physical condition, particularly the foreign guy, Marek. He looked strong. And the woman wasn't bad, either. Good muscle tone in the arms, calluses on her hands. Competent manner. So she might hold up under pressure, he thought.

But the good-looking kid would be useless. Gordon sighed as Chris Hughes looked out the window, caught his own reflection in the glass, and brushed back his hair with his hand.

And Gordon couldn't decide about the fourth kid, the nerdy one. He'd obviously spent time outdoors; his clothes were faded and his glasses scratched. But Gordon recognized him as a tech guy. Knew everything about equipment and circuits, nothing about the world. It was hard to say how he'd react if things got tough.

The big man, Marek, said, "Are you going to tell us what's going on?"

"I think you already know, Mr. Marek," Gordon said. "Don't you?"

"I have a piece of six-hundred-year-old parchment with the Professor's writing on it. In six-hundred-year-old ink."

"Yes. You do."

Marek shook his head. "But I have trouble believing it."

"At this point," Gordon said, "it's simply a technological reality. It's real. It can be done." He got out of his seat and moved to sit with the group.

"You mean time travel," Marek said.

"No," Gordon said. "I don't mean time travel at all. Time travel is impossible. Everyone knows that."

"The very concept of time travel makes no sense, since time doesn't flow. The fact that we think time passes is just an accident of our nervous systems  -  of the way things look to us. In reality, time doesn't pass; we pass. Time itself is invariant. It just is. Therefore, past and future aren't separate locations, the way New York and Paris are separate locations. And since the past isn't a location, you can't travel to it."

They were silent. They just stared at him.

"It is important to be clear about this," Gordon said. "The ITC technology has nothing to do with time travel, at least not directly. What we have developed is a form of space travel. To be precise, we use quantum technology to manipulate an orthogonal multiverse coordinate change."

They looked at him blankly.

"It means," Gordon said, "that we travel to another place in the multiverse."

"And what's the multiverse?" Kate said.

"The multiverse is the world defined by quantum mechanics. It means that - "

"Quantum mechanics?" Chris said. "What's quantum mechanics?"

Gordon paused. "That's fairly difficult. But since you're historians," he said, "let me try to explain it historically."

"A hundred years ago," Gordon said, "physicists understood that energy  -  like light or magnetism or electricity  -  took the form of continuously flowing waves. We still refer to 'radio waves' and 'light waves.' In fact, the recognition that all forms of energy shared this wavelike nature was one of the great achievements of nineteenth-century physics.

"But there was a small problem," he said. It turned out that if you shined light on a metal plate, you got an electric current. The physicist Max Planck studied the relationship between the amount of light shining on the plate and the amount of electricity produced, and he concluded that energy wasn't a continuous wave. Instead, energy seemed to be composed of individual units, which he called quanta. "The discovery that energy came in quanta was the start of quantum physics," Gordon said.

"A few years later, Einstein showed that you could explain the photoelectric effect by assuming that light was composed of particles, which he called photons. These photons of light struck the metal plate and knocked off electrons, producing electricity. Mathematically, the equations worked. They fit the view that light consisted of particles. Okay so far?"

"Yes. . . ."

"And pretty soon, physicists began to realize that not only light, but all energy was composed of particles. In fact, all matter in the universe took the form of particles. Atoms were composed of heavy particles in the nucleus, light electrons buzzing around on the outside. So, according to the new thinking, everything is particles. Okay?"

"Okay. . . ."

"The particles are discrete units, or quanta. And the theory that describes how these particles behave is quantum theory. A major discovery of twentieth-century physics."

They were all nodding.

"Physicists continue to study these particles, and begin to realize they're very strange entities. You can't be sure where they are, you can't measure them exactly, and you can't predict what they will do. Sometimes they behave like particles, sometimes like waves. Sometimes two particles will interact with each other even though they're a million miles apart, with no connection between them. And so on. The theory is starting to seem extremely weird.

"Now, two things happen to quantum theory. The first is that it gets confirmed, over and over. It's the most proven theory in the history of science. Supermarket scanners, lasers and computer chips all rely on quantum mechanics. So there is absolutely no doubt that quantum theory is the correct mathematical description of the universe.

"But the problem is, it's only a mathematical description. It's just a set of equations. And physicists couldn't visualize the world that was implied by those equations  -  it was too weird, too contradictory. Einstein, for one, didn't like that. He felt it meant the theory was flawed. But the theory kept getting confirmed, and the situation got worse and worse. Eventually, even scientists who won the Nobel Prize for contributions to quantum theory had to admit they didn't understand it.

"So, this made a very odd situation. For most of the twentieth century, there's a theory of the universe that everyone uses, and everyone agrees is correct  -  but nobody can tell you what it is saying about the world."

"What does all this have to do with multiple universes?" Marek said.

"I'm getting there," Gordon said.

Many physicists tried to explain the equations, Gordon said. Each explanation failed for one reason or another. Then in 1957, a physicist named Hugh Everett proposed a daring new explanation. Everett claimed that our universe  -  the universe we see, the universe of rocks and trees and people and galaxies out in space  -  was just one of an infinite number of universes, existing side by side.

Each of these universes was constantly splitting, so there was a universe where Hitler lost the war, and another where he won; a universe where Kennedy died, and another where he lived. And also a world where you brushed your teeth in the morning, and one where you didn't. And so forth, on and on and on. An infinity of worlds.

Everett called this the "many worlds" interpretation of quantum mechanics. His explanation was consistent with the quantum equations, but physicists found it very hard to accept. They didn't like the idea of all these worlds constantly splitting all the time. They found it unbelievable that reality could take this form.

"Most physicists still refuse to accept it," Gordon said. "Even though no one has ever shown it is wrong."

Everett himself had no patience with his colleagues' objections. He insisted the theory was true, whether you liked it or not. If you disbelieved his theory, you were just being stodgy and old-fashioned, exactly like the scientists who disbelieved the Copernican theory that placed the sun at the center of the solar system  -  and which had also seemed unbelievable at the time. "Because Everett claimed the many worlds concept was actually true. There really were multiple universes. And they were running right alongside our own. All these multiple universes were eventually referred to as a 'multiverse.' "

"Wait a minute," Chris said. "Are you telling us this is true?"

"Yes," Gordon said. "It's true."

"How do you know?" Marek said.

"I'll show you," Gordon said. And he reached for a manila file that said "ITC/CTC Technology."

He took out a blank piece of paper, and began drawing. "Very simple experiment, it's been done for two hundred years. Set up two walls, one in front of the other. The first wall has a single vertical slit in it."

He showed them the drawing.

"Now you shine a light at the slit. On the wall behind, you'll see - "

"A white line," Marek said. "From the light coming through the slit."

"Correct. It would look something like this." Gordon pulled out a photo on a card.

Gordon continued to sketch. "Now, instead of one slit, you have a wall with two vertical slits in it. Shine a light on it, and on the wall behind, you see - "

"Two vertical lines," Marek said.

"No. You'll see a series of light and dark bars." He showed them:

"And," Gordon continued, "if you shine your light through four slits, you get half as many bars as before. Because every other bar goes black."