"Can you get to where I am?"

"Yeah."

She heard him splashing somewhere in the darkness behind.

Once he was back in the boat, soaked but smiling, she let go of the stalactite and they began moving again with the current. They spent several more minutes in the stalactite forest, and then they came out into an open chamber again. The current moved faster. From somewhere ahead, they heard a roaring sound. It sounded like a waterfall.

But then she saw something that made her heart leap. It was a large stone block by the side of the river. The block was worn around the sides from rope chafing. It had clearly been used to tie up boats.

"Chris. . . ."

"I see it."

She saw what looked like a worn path beyond the block, but she couldn't be sure. Chris rowed to the side, and they tied up the boat and got out. There was a definite path, leading to a tunnel with smooth, artificially cut walls. They started down the tunnel. She held the torch in front of her.

She caught her breath.

"Chris? There's a step."

"What?"

"A step. Cut in the rock. About fifty feet ahead." She moved faster. They both moved faster. "In fact," she said, raising the torch higher, "there's more than a step. There's a whole staircase."

By the flickering torchlight, they saw more than a dozen steps, rising at a steep angle upward, without a railing, until they ended in a stone ceiling  -  a trapdoor fitted with an iron handle.

She handed Chris the torch, then scrambled up the stairs. She pulled at the ring, but nothing happened. She pushed at it, putting her shoulder into it.

She managed to raise the stone an inch.

She saw yellow light, so bright that it made her squint. She heard the roar of a nearby fire, and the laughter of men's voices. Then she couldn't hold the weight any longer, and the stone came back down again.

Chris was already coming up the stairs toward her. "Earpieces on," he said, tapping his ear.

"You think?"

"We have to risk it."

She tapped her ear, heard the crackle. She heard Chris's breathing, amplified as he stood beside her on the narrow ledge.

She said, "I'll go first." She reached into her pocket, took out the marker, and gave it to him. He frowned. She said, "Just in case. We don't know what's on the other side."

"Okay." Chris set the torch down, then leaned his shoulder against the trapdoor. The stone crunched, moved upward. She scrambled through the opening, then helped him quietly swing the door all the way open and lay it on the floor.

They had made it.

They were inside La Roque.

01:13:52

Robert Doniger spun, holding the microphone in his hand. "Ask yourself," he said to the empty, darkened auditorium. "What is the dominant mode of experience at the end of the twentieth century? How do people see things, and how do they expect to see things? The answer is simple. In every field, from business to politics to marketing to education, the dominant mode has become entertainment."

Across from the narrow stage, three padded booths had been set up, all in a row. Each booth contained a desk and chair, a notepad, and a glass of water. Each booth was open at the front, so that a person in the booth could see only Doniger, and not the people in the other booths.

This was the way Doniger gave his presentations. It was a trick he had learned from old psychological studies of peer pressure. Each person knew there were people in the other booths, but he couldn't see or hear them. And it put tremendous pressure on the listeners. Because they had to worry what the other people were going to do. They had to worry if the other people were going to invest.

He walked back and forth across the stage. "Today, everybody expects to be entertained, and they expect to be entertained all the time. Business meetings must be snappy, with bullet lists and animated graphics, so executives aren't bored. Malls and stores must be engaging, so they amuse as well as sell us. Politicians must have pleasing video personalities and tell us only what we want to hear. Schools must be careful not to bore young minds that expect the speed and complexity of television. Students must be amused  -  everyone must be amused, or they will switch: switch brands, switch channels, switch parties, switch loyalties. This is the intellectual reality of Western society at the end of the century.

"In other centuries, human beings wanted to be saved, or improved, or freed, or educated. But in our century, they want to be entertained. The great fear is not of disease or death, but of boredom. A sense of time on our hands, a sense of nothing to do. A sense that we are not amused.

"But where will this mania for entertainment end? What will people do when they get tired of television? When they get tired of movies? We already know the answer  -  they go into participatory activities: sports, theme parks, amusement rides, roller coasters. Structured fun, planned thrills. And what will they do when they tire of theme parks and planned thrills? Sooner or later, the artifice becomes too noticeable. They begin to realize that an amusement park is really a kind of jail, in which you pay to be an inmate.

"This artifice will drive them to seek authenticity. Authenticity will be the buzzword of the twenty-first century. And what is authentic? Anything that is not devised and structured to make a profit. Anything that is not controlled by corporations. Anything that exists for its own sake, that assumes its own shape. But of course, nothing in the modern world is allowed to assume its own shape. The modern world is the corporate equivalent of a formal garden, where everything is planted and arranged for effect. Where nothing is untouched, where nothing is authentic.

"Where, then, will people turn for the rare and desirable experience of authenticity? They will turn to the past.

"The past is unarguably authentic. The past is a world that already existed before Disney and Murdoch and Nissan and Sony and IBM and all the other shapers of the present day. The past was here before they were. The past rose and fell without their intrusion and molding and selling. The past is real. It's authentic. And this will make the past unbelievably attractive. That's why I say that the future is the past. The past is the only real alternative to  -  Yes? Diane, what is it?" He turned as she walked into the room.

"There's a problem in the transit room. It seems the explosion damaged the remaining water shields. Gordon's run a computer simulation that shows three shields breaking when they're filled with water."

"Diane, this is a goddamn no-brainer," Doniger said, tugging at his tie. "Are you telling me they may come back unshielded?"

"Yes."

"Well, we can't risk that."

"It's not that simple. . . ."

"Yes, it is," Doniger said. "We can't take the risk. I'd rather they didn't come back at all than to have them come back seriously damaged."

"But - "

"But what? If Gordon has this computer projection, why is he going forward?"

"He doesn't believe the projection. He says it's quick and dirty, and he thinks the transit will go fine."

"We can't risk it," Doniger said, shaking his head. "They can't come back without shields. Period."

She paused, bit her lip. "Bob, I think the - "

"Hey," he said. "We got short-term-memory loss here? You were the one who wouldn't let Stern go back, because of the risk of transcription errors. Now you want to let the whole goddamn bunch come back unshielded? No, Diane."

"Okay," she said, obviously reluctant. "I'll go and talk to - "

"No. No talk. Kill it. Pull the power plug if you have to. But don't let those people come back. I'm right about this, and you know it."

In the control room, Gordon said, "He said what?"

"They can't come back. Absolutely not. Bob was firm."

"But they have to come back," David Stern said. "You have to let them."

"No, I don't," Kramer said.

"But - "

"John," Kramer said, turning to Gordon. "Has he seen Wellsey? Have you shown him Wellsey?"

"Who's Wellsey?"

"Wellsey's a cat," Gordon said.

"Wellsey's split," Kramer said to Stern. "He was one of the first test animals that we sent back. Before we knew that you had to use water shields in a transit. And he's very badly split."

"Split?"

Kramer turned to Gordon. "Haven't you told him anything?"

"Of course I told him," Gordon said. He said to Stern, "Split means he had very severe transcription errors." He turned back to Kramer. "But that happened years ago, Diane, back when we also had problems with the computers as well - "

"Show him," Kramer said. "And then see if he's still so eager to bring his friends back. But the point of the conversation is, Bob's made his decision on this, and the answer is no. If we don't have secure shields, nobody can come back. Under any circumstances."

At the consoles, one of the technicians said, "We've got a field buck."

They crowded around the monitor, looking at the undulating wave and the tiny ripples in the surface.

"How long before they come back?" Stern said.

"Judging from this signal, about an hour."

"Can you tell how many?" Gordon said.

"Not yet, but . . . it's more than one. Maybe four, or five."

"That's all of them," Gordon said. "They must have gotten the Professor, and they're all coming home. They've done what we asked them to do, and they're coming back."

He turned to Kramer.

"Sorry," she said. "If there're no shields, nobody comes back. That's final."

01:01:52

Crouched beside the trapdoor, Kate got slowly to her feet. She was standing in a narrow space, no more than four feet wide, with high stone walls on either side. Firelight was coming in from an opening to her left. By its yellow light, she saw a door directly ahead of her. Behind her was a set of stairs, going steeply upward to the top of the chamber, some thirty feet above.

But where was she?

Chris peered over the edge of the trapdoor, and pointed to the firelight. He whispered, "I think we know why they never found the door to this passage."

"Why?"

"It's behind the fireplace."

"Behind the fireplace?" she whispered. And then she realized he was right. This narrow space was one of the secret passages of La Roque: behind the fireplace of the great hall.

Kate moved forward cautiously, past the wall to her left  -  and found herself staring out from the back wall of the fireplace in the great hall. The fireplace was nine feet high. Through the leaping flames, she saw Oliver's high table, where his knights were sitting and eating, their backs to her. She could not be more than fifteen feet from them.

She whispered, "You're right. It's behind the fireplace."

She looked back to Chris, then beckoned him to come forward. She was about to continue to the door directly ahead when Sir Guy glanced back at the fire as he tossed a chicken wing into the flames. He turned back to the table, resumed eating.

She thought, Get out of here.

But it was too late. Guy's shoulders twitched; he was already turning back again. He saw her clearly, his eyes met hers, and he shouted, "My Lord!" He pushed back from the table and drew his sword.

Kate ran to the door, tugged at it, but it was locked, or stuck shut. She couldn't open it. She turned back to the narrow stairs behind her. She saw Sir Guy standing on the other side of the flames, hesitating. He looked at her again, and plunged through the fire toward her. She saw Chris coming through the trapdoor and said, "Down!" He ducked down as she scrambled up the stairs.

Sir Guy swung at her feet, narrowly missing her, his sword clanging off the stone. He cursed her, then looked down at the opening to the passage below. Apparently he didn't see Chris, because immediately afterward she heard him coming up the stairs behind her.

She had no weapon; she had nothing.

She ran.

At the top of the stairs, thirty feet above the ground, was a narrow platform, and when she reached it, she felt a thicket of cobwebs clinging to her face. She brushed them away impatiently. The platform could not have been more than two feet square. It was precarious, but she was a climber and it didn't bother her.

But it bothered Sir Guy. He was moving very slowly up the stairs toward her, pressing his shoulder against the wall, keeping as far from the edge of the stairs as he could, clutching at tiny handholds in the mortar of the wall. He had a desperate look and he was breathing hard. So, the valiant knight was afraid of heights. But not afraid enough to stop, she saw. If anything, his discomfort seemed to make him angrier. He glared at her with murderous intent.

The platform faced a rectangular wooden door, fitted with a round view hole the size of a quarter. The stairs had clearly been built to lead to this hole, allowing an observer to look down on the great hall and see everything that occurred there. Kate pushed at the door, leaning her weight against it, but instead of opening, the entire rectangle fell through, dropping onto the floor of the great hall below, and she half-fell through after it.

She was inside the great hall.

She was up high, among the heavy wooden beams of the open ceiling. She looked down at the tables thirty feet below her. Directly ahead was the enormous central rafter, running the length of the hall. This beam was crisscrossed with horizontal rafters every five feet, which ran out to the walls on both sides. All the rafters were elaborately carved, and cross-braced at intervals.

Without hesitation, Kate stepped out onto the central beam. Everyone below was looking up; they gasped when they saw her, pointed upward. She heard Oliver cry loudly, "Saint George and damnation! The assistant! We are betrayed! The Magister!"

He pounded the table, and stood, glaring up at her.

She said, "Chris. Find the Professor."

She heard a crackle. " - kay."

"Did you hear me? Chris."

Just a static crackle.

Kate moved quickly down the center rafter. Despite the height above the floor, she felt perfectly comfortable. The beam was a foot wide. Nothing to it. Hearing another gasp from the people below, she glanced back and saw Sir Guy step out on the center beam. He seemed frightened, but the presence of an audience emboldened him. Either that or he was unwilling to show fear at so public a moment. Guy took a hesitant step, found his balance, and came directly for her, moving rapidly. He swung the sword loosely in his hand. He reached the first vertical brace, took a breath, and, holding on to the upright post, maneuvered his body around it. He continued on down the center beam.

Kate backed away, realizing that this center beam was too wide, too easy for him. She walked laterally along a horizontal rafter, heading toward the side wall. This horizontal rafter was only six inches wide; he would have trouble. She clambered around a difficult cross-braced section, then continued on.

Only then did she realize her mistake.

Generally, open medieval ceilings had a structural detail where they met the wall  -  another brace, a decorative beam, some sort of rafter that she could move along. But this ceiling reflected the French style: the beam ran straight into the side wall, where it fitted into a notch some four feet below the line of the roof. There was no wall detail at all. She remembered now that she had stood in the ruins of La Roque and had seen those notches. What was she thinking of?

She was trapped on the beam.

She couldn't go farther out, because the beam ended at the wall. She couldn't go back to the center, because Guy was there, waiting for her. And she couldn't go to the next parallel rafter, because it was five feet away, very far to jump.

Not impossible, but far. Especially without a safety.

Looking back, she saw Sir Guy coming out along the beam toward her, balancing cautiously, swinging his sword lightly in his hand. He smiled grimly as he came forward. He knew he had caught her.

She had no choice now. She looked at the next beam, five feet away. She had to do it. The problem was to get enough height. She had to jump up if she hoped to make it across.

Guy was working his way around the cross-beam bracing. He was only seconds away from her now. She crouched on the beam, took a breath, tensed her muscles  -  and kicked hard with her legs, sending her body flying out into open space.

Chris came up through the stone trapdoor. He looked through the fire and saw that everybody in the room was staring up at the ceiling. He knew Kate was up there, but there was nothing he could do for her. He went directly to the side door and tried to open it. When it didn't budge, he slammed his full weight against it, felt it give an inch. He shoved again; the door creaked, then swung wide.

He stepped out into the inner courtyard of La Roque. Soldiers were running everywhere. A fire had broken out in one of the hoardings, the wooden galleries that ran along the top of the walls. Something was burning like a bonfire in the center of the courtyard itself. Amid the chaos, no one paid any attention to him.

He said, "Andre. Are you there?"

A static crackle. Nothing.

And then: "Yes." It was Andre's voice.

"Andre? Where are you?"

"With the Professor."

"Where?" Chris said.

"The arsenal."

"Where is that?"

00:59:20

There were two dozen animals in cages in the laboratory storeroom, mostly cats, but also some guinea pigs and mice. The room smelled of fur and feces. Gordon led him down the aisle, saying, "We keep the split ones isolated from the others. We have to."

Stern saw three cages along the back wall. The bars of these cages were thick. Gordon led him to one, where he saw a small, curled-up bundle of fur. It was a sleeping cat, a Persian, pale gray in color.

"This is Wellsey," Gordon said, nodding.

The cat seemed entirely normal. It breathed slowly, gently, as it slept. He could see half the face above the curve of the fur. The paws were dark. Stern leaned closer, but Gordon put his hand on his chest. "Not too close," he said.

Gordon reached for a stick, ran it along the bars of the cage.

The cat's eye opened. Not slowly and lazily  -  it opened wide, instantly alert. The cat did not move, did not stretch. Only the eye moved.

Gordon ran the stick along the bars a second time.

With a furious hiss, the cat flung itself against the bars, mouth wide, teeth bared. It banged against the bars, stepped back, and attacked again  -  and again, relentlessly, without pause, hissing, snarling.

Stern stared in horror.

The animal's face was hideously distorted. One side appeared normal, but the other side was distinctly lower, the eye, the nostril, everything lower, with a line down the center of the face, dividing the halves. That's why they called it "split," he thought.

But worse was the far side of the face, which he didn't see at first, with the cat lunging and banging against the bars, but now he could see that back on the side of the head, behind the distorted ear, there was a third eye, smaller and only partially formed. And beneath that eye was a patch of nose flesh, and then a protruding bit of jaw that stuck out like a tumor from the side of the face. A curve of white teeth poked out from the fur, though there was no mouth.

Transcription errors. He now understood what that meant.

The cat banged again and again; its face was starting to bleed with the repeated impacts. Gordon said, "He'll do that until we leave."

"Then we better leave," Stern said.

They walked back in silence for a while. Then Gordon said, "It's not just what you can see. There are mental changes, too. That was the first noticeable change, in the person who was split."

"This is the person you were telling me about? The one who stayed back?"

"Yes," Gordon said. "Deckard. Rob Deckard. He was one of our marines. Long before we saw physical changes in his body, there were mental changes. But we only understood later that transcription errors were the cause."

"What kind of mental changes?"

"Originally, Rob was a cheerful guy, very good athlete, extremely gifted with languages. He would sit around having a beer with somebody foreign, and by the end of the beer he'd have started to pick up the language. You know, a phrase here, a sentence there. He'd just start speaking. Always with a perfect accent. After a few weeks, he could speak like a native. The marines spotted it first, and had sent him to one of their language schools. But as time went by, and Rob accumulated more damage, he wasn't so cheerful anymore. He turned mean," Gordon said. "Really mean."

"Yes?"

"He beat the hell out of the gate guard here, because the guard took too long checking his ID. And he practically killed a guy in an Albuquerque bar. That was when we started to realize that Deckard had permanent damage to his brain, and it wasn't going to get better, that if anything, it would get worse."

Back in the control room, they found Kramer hunched over the monitor, staring at the screen, which showed the field fluctuations. They were coming more strongly now. And the technicians were saying that at least three were coming back, and maybe four or five. From her expression, it was clear Kramer was torn; she wanted to see them all come back.

"I still think the computer is wrong, and the panels will hold," Gordon said. "We certainly can fill the tanks now and see if they hold."

Kramer nodded. "Yes, we can do that. But even if they fill without breaking, we can't be certain they won't blow out later, in the middle of the transit. And that would be a disaster."

Stern shifted in his seat. He felt suddenly uneasy. Something was nagging at him, tickling the back of his mind. When Kramer said "blow out," he once more saw automobiles in his mind  -  the same succession of images, all over again. Car races. Huge truck tires. Michelin Man. A big nail in the road, and a tire driving over it.

Blowout.

The water tanks would blow out. The tires would blow out. What was it about blowouts?

"To pull this off," Kramer said, "we somehow need to strengthen the tanks."

"Yes, but we've been over that," Gordon said. "There's just no way to do it."

Stern sighed. "How much time left?"

The technician said, "Fifty-one minutes, and counting."

00:54:00

To Kate's astonishment, she heard applause from the floor below. She had made the jump; she swung back and forth, dangling beneath the beam. And down on the floor, they were applauding, as if this were a circus act.

She quickly kicked her legs up and clambered onto the beam.

On the rafter behind her, Guy Malegant was hurrying back to the centerline beam. He clearly intended to try to block her return from her present rafter.

She ran down the beam, back to the center of the ceiling. She was more agile than Guy, and she arrived at the wide central rafter well before he did. She had a moment to collect herself, to decide what to do.

What was she going to do?

She was standing in the middle of the open roof, holding on to a thick vertical strut, about twice the diameter of a telephone pole. The strut had supporting braces that angled out diagonally on both sides, starting midway up the shaft and then connecting to the roof. These braces were so low that if Sir Guy intended to get to her, he would have to crouch down as he made his way around the strut.

Kate crouched down now, seeing what it felt like to move around under the brace. It was awkward, and it would be slow. She got to her feet again. As she did so, her hand brushed her dagger. She'd forgotten she had it. She drew it out now, held it in front of her.

Guy saw her, and laughed. His laughter was picked up by the watching crowd on the floor below. Guy shouted something down to them, which made them laugh all the harder.

She watched him come toward her, and she backed away. She was allowing him room to move around the vertical strut. She tried to look terrified  -  it wasn't difficult  -  and she cowered, her knife trembling in her hand.

It's all going to be timing, she thought.

Sir Guy paused on the far side of the strut, watching her for a moment. Then he crouched down and started to make his way around the strut. His hand was wrapped around the wood, the sword in his right hand temporarily pressed against the strut.

She ran forward and stabbed his hand with the dagger, pinning it to the strut. Then she swung around to the opposite side of the strut and kicked his feet off the central beam. Guy fell into space, dangling from his pinned hand. He clenched his teeth but didn't make a sound. Jesus, these guys were tough!

Still clutching his sword, he tried to get back up on the beam. But by then she had swung back to her original position, on the other side of the beam. His eyes met hers.

He knew what she was going to do.

"Rot in hell," he snarled.

"You first," she said.

She pulled her dagger free from the wood. Guy fell silently to the ground below, his body growing smaller. Halfway down, he struck a pole from which a banner hung; his body caught on the wrought-iron point, and for a moment he hung there; then the pole snapped and he slammed onto a table, sending crockery flying. The guests jumped back. Guy lay among the broken crockery. He didn't move.

Oliver was pointing up at Kate and shouting, "Kill him! Kill him!" The cry was taken up around the room. Archers ran for weapons.

Oliver did not wait; in a fury, he stomped out of the hall, taking several soldiers with him.

She heard maids in waiting, young children, everyone, chanting, "Kill him!" and she sprinted along the center beam, going for the wall at the far end of the great hall. Arrows whooshed past her, thunked into the wood. But they were too late; she could see that there was a second door in the other wall, matching the first, and she hit it hard, knocking it open, and crawled out of the hall, into darkness.

It was a very tight space. She banged her head against the ceiling, and she realized that this was the north end of the great hall, which meant it was freestanding and did not abut the castle wall. Therefore . . .

She pushed upward, at the roof. A section gave way. She stepped out onto the roof, and from there she climbed easily up onto the ramparts of the inner wall.

From here, she could see the siege was fully under way. Volleys of fiery arrows hissed overhead in smooth arcs, then descended to the courtyard below. Archers on the battlements returned the fire. Cannon on the battlements were being loaded with metal arrows, with de Kere striding back and forth, barking instructions. De Kere didn't notice her.

She turned away, pressed her ear and said, "Chris?"

De Kere spun, his hand clapped over his ear. Suddenly he was turning, looking everywhere, along the length of the battlements and down into the courtyard.

It was de Kere.

And then de Kere saw her. He recognized her immediately.

Kate ran.

Chris said, "Kate? I'm down here." Flaming arrows were slashing down all over the courtyard. He waved to her up on the wall, but he was not sure she could see him in the darkness.

She said, "It's - " but the rest was lost in static. By then he had turned away, watching Oliver and four soldiers cross the courtyard, and go into a square building that he assumed was the arsenal.

Chris at once began to follow, when a flaming ball landed at his feet, bounced, and rolled to a stop. Through the flames he could see that it was a human head, eyes open, lips drawn back. The flesh burned, the fat popping. A passing soldier kicked it away like a soccer ball.

One of the arrows raining down on the courtyard brushed past his shoulder and left behind a streak of flame on his sleeve. He could smell the pitch and feel the heat on his arm and face. Chris threw himself onto the ground, but the fire did not go out. It seemed to be smoldering; the heat became worse. He got to his knees and, using his dagger, cut his doublet open. He shrugged out of the burning coat and threw it aside. The back of his hand was still aflame, from tiny drops of pitch. He rubbed his hand in the dust of the courtyard.

The fire at last went out.

Standing again, he said, "Andre? I'm coming." But there was no answer. Alarmed, he jumped to his feet, just in time to see Oliver emerge from the arsenal, leading the Professor and Marek away, heading to a far door in the castle wall. The soldiers pushed them forward at swordpoint. Chris didn't like the look of it. He had the uneasy sense that Oliver was going to kill them.

"Kate."

"Yes, Chris."

"I see them."

"Where?"

"Going into that corner door."

He started to follow, realized he needed a weapon. Just a few feet away, a burning arrow struck a soldier in the back, knocking him face down on the ground. Chris bent over, took the man's sword, then stood again and turned to go.

"Chris."

A man's voice, in his earpiece. An unfamiliar voice that he didn't recognize. Chris looked around, but saw only running soldiers, flaming arrows whizzing through the air, a burning courtyard.

"Chris." The voice was soft. "Over here."

Through the flames he saw a dark figure standing motionless as a statue, staring at him across the courtyard. This dark figure ignored the fighting that swirled around him. He stared fixedly at Chris. It was Robert de Kere.

"Chris. Do you know what I want?" de Kere said.

Chris didn't answer him. Nervously, he hefted the sword in his hand, feeling the weight. De Kere just watched him. He chuckled softly. "Are you going to fight me, Chris?"

And then de Kere started walking toward him.

Chris took a breath, not certain whether to stay or run. And suddenly a door behind the great hall burst open and a knight came out, in full armor except for his helmet, bellowing, "For God and the Archpriest Arnaut!" He recognized the handsome knight, Raimondo. Dozens of soldiers in green and black were pouring out into the courtyard, engaging Oliver's troops in a pitched battle.

De Kere was still stalking him, but now he paused, uncertain about this new development. Suddenly Arnaut grabbed Chris by the throat, holding his sword high. Arnaut pulled him close, shouting, "Oliver! Where is Oliver!"

Chris pointed to the far door.

"Show me!"

He went with Arnaut across the courtyard, through the door. Following stairs spiraling downward, they came to a series of underground chambers. They were large and gloomy, with high curved ceilings.

Arnaut pushed ahead, panting, red-faced with fury. Chris hurried to keep up with him. They passed through a second chamber, empty like the first. But now Chris heard voices up ahead. One of them sounded like the Professor's.

00:36:02

On the control room monitors, the computer-generated undulating field had begun to show spikes. Biting her lip, Kramer watched the spikes grow in higher and wider. She drummed her fingers on the table. Finally, she said, "Okay. Let's fill the tanks at least. Let's see how they do."

"Good," Gordon said, looking relieved. He picked up the radio, began to give orders to the technicians down in the transit room.

On the video monitors, Stern watched as heavy hoses were dragged over to the first of the empty shield tanks. Men climbed up ladders and adjusted the nozzles. "I think this is best," Gordon said. "At least we'll - "

Stern jumped to his feet. "No," he said. "Don't do it."

"What?"

"Don't fill the tanks."

Kramer stared at him. "Why? What can - "

"Don't do it!" Stern said. He was shouting in the small control room. On the screen, technicians were holding water nozzles above the fill aperture. "Tell them to stop! No water whatever in the tank! Not a drop!"

Gordon gave an order on the radio. The technicians looked up in surprise, but they stopped their work, lowered the hoses back to the floor.

"David," Gordon said gently. "I think we have to - "

"No," Stern said. "We don't fill the tanks."

"Why not?"

"Because it'll screw up the glue."

"The glue?"

"Yes," he said. "I know how to strengthen the tanks."

Kramer said, "You do? How?"

Gordon turned to the technicians. "How much time?"

"Thirty-five minutes."

He turned back to Stern. "There's just thirty-five minutes, David. There isn't time to do anything now."

"Yes there is," Stern said. "There's still enough time. If we go like hell."

00:33:09

Kate came into the central courtyard of La Roque, to the place where she had last seen Chris. But Chris was gone.

"Chris?"

She heard no answer in her earpiece.

And he had the ceramic, she thought.

All around her in the courtyard lay burning bodies. She ran from one to the next, looking to see if one of them was Chris.

She saw Raimondo, who gave her a little nod and a wave  -  and then he shuddered. For a moment she thought it was the heat waves from the flames, but then she saw Raimondo turn, bleeding from his side. There was a man standing behind him, hacking repeatedly with his sword, cutting Raimondo at the arm, shoulder, torso, leg. Every cut was deep enough to wound, but not to kill. Raimondo staggered backward, bleeding freely. The man advanced, still hacking. Raimondo fell to his knees. The man stood over Raimondo, cutting again and again. Raimondo fell backward, and now the man was slashing Raimondo's face, cutting diagonally across lips and nose, sending bits of flesh flying. The attacker's face was hidden by flames, but she heard him say, "Bastard, bastard, bastard," with each blow. She realized he was speaking English. And then she knew who the man was.

The attacker was de Kere.

Chris followed Arnaut deeper into the dungeon. They heard voices echoing somewhere up ahead. Arnaut moved more cautiously now, staying closer to the walls. At last they could see into the next chamber, which was dominated by a large pit in the ground. Above the pit, a heavy metal cage hung from a chain. The Professor was standing inside the bars, his face expressionless as the cage was lowered by two soldiers who turned a winch crank. Marek had been pushed against the far wall, his hands tied. Two soldiers stood near him.

Lord Oliver stood at the edge of the pit, smiling as the cage descended. He drank from a gold cup, wiped his chin. "I made you my promise, Magister," he said, "and I will keep it." To the soldiers at the winch he said, "Slower, slower."

Staring at Oliver, Arnaut growled like an angry dog, and drew his sword. He turned back to Chris and whispered, "I shall take Oliver. You may have the others."

Chris thought: The others? There were four soldiers in the room. But he had no time to protest, for with a scream of fury, Arnaut was running forward, shouting, "Oliverrrrr!"

Lord Oliver turned, still holding his goblet. With a sneer of disdain, he said, "So. The pig approaches." He threw his cup aside and drew his sword. In a moment the battle was joined.

Chris was now running toward the soldiers at the winch, not quite sure what he would do; the soldiers beside Marek had raised their swords. Oliver and Arnaut fought bitterly, swords clanging, cursing each other between blows.

Everything was happening fast now. Marek tripped one of the soldiers near him, and stabbed him with a knife so small Chris couldn't see it. The other soldier turned back to face Marek, and Marek kicked him hard, so that he staggered back against the winch, knocking the men away.

Unattended, the winch began to clank down more rapidly. There was a ratchet mechanism of some kind, so it turned noisily, but it was clearly moving faster than before. Chris saw the Professor's cage descend below ground level, disappearing into the pit.

By then Chris had reached the first of the soldiers, whose back was to him. The man started to turn and Chris swung, badly wounding him. He swung again; the man fell.

Now there were only two soldiers. Marek, his wrists still tied, was backing away from one, ducking the hissing blade. The second soldier stood by the winch. He had his sword out and was ready to fight. Chris swung; the man parried easily. Then Marek, backing in a circle, banged against the soldier, who turned momentarily. Marek shouted, "Now!" and Chris stabbed with the sword. The man collapsed.

The winch was still turning. Chris grabbed it, then jumped away as the fourth soldier's sword came down with a clang. The cage sank lower. Chris backed away. Marek was holding his bound wrists out to Chris; but Chris was not sure he could control the sword. Marek was shouting, "Do it!" so Chris swung; the rope snapped; and then the fourth soldier was on him. The soldier fought with the fury of a man trapped; Chris was cut on the forearm as he backed away. He realized he was in trouble, when suddenly his attacker looked down in horror, the bloody point of a sword protruding from his abdomen. The soldier toppled, and Chris saw Marek holding the blade.

Chris ran for the winch. He grabbed the crank and managed to stop the descent. Now he could see that the cage was deep in the oily water; the Professor's head was barely above the surface. Another turn of the crank and he would have been submerged.

Marek came over, and together they began to crank the cage back up. Chris said, "How much time is left?"

Marek looked at his counter. "Twenty-six minutes."

Meanwhile, Arnaut and Oliver fought on; they were now in a dark corner of the dungeon, and Chris could see the sparks from their clashing swords.

The cage rose dripping into the air. The Professor smiled at Chris. "I thought you'd be in time," he said.

The black bars of the cage were slippery in Chris's hands as he swung the cage overhead, away from the pit. Slime and black water dripped onto the dirt floor of the dungeon, leaving little pools. Chris went back to the winch; he and Marek cranked the cage down, lowering it to the floor. The Professor was soaked, but he seemed relieved to be on solid ground again. Chris went back to open the cage, but he saw that it was locked. There was a heavy iron padlock the size of a man's fist.

"Where's the key?" Chris said, turning to Marek.

"I don't know," Marek said. "I was on the ground when they put him in, I didn't see what happened."

"Professor?"

Johnston shook his head. "I'm not sure. I was looking there." He nodded toward the pit.

Marek clanged his sword against the lock. Sparks flew, but the padlock was solid; the sword only scratched it. "That's never going to work," Chris said. "We need the damn key, Andre."

Andre turned and looked around the dungeon. Chris said, "How much time is left?"

"Twenty-five minutes."

Shaking his head, Chris went to the nearest dead soldier, and began searching the body.

00:21:52

In the control room, Stern watched as the technicians dipped the pale rubber membrane into a bucket of adhesive, and then placed it, still dripping, inside the mouth of the glass shield. Then they attached a compressed-air hose and the rubber began to expand. For a moment, it was possible to see that it was a weather balloon, but then it expanded still further, the rubber spreading and thinning, becoming translucent, assuming the curving shape of the glass shield until it had reached every corner of the container. Then the technicians capped it, clicked a stopwatch, and waited while the adhesive hardened.

Stern said, "How much time?"

"Twenty-one minutes to go." Gordon pointed to the balloons. "It's homely, but it works."

Stern shook his head. "It was staring me in the face, for the last hour."

"What was?"

"Blowouts," he said. "I kept thinking, what are we trying to avoid here? And the answer is, blowouts. Just like a car, when the tires blow out. I kept thinking of car blowouts. And it seemed odd, because blowouts are so rare now. New cars hardly ever have them. Because the new tires have an inner membrane that's self-sealing." He sighed. "I kept wondering why this rare thing was on my mind, and then I realized that was the whole point: there was a way to make a membrane here, too."

"This is not self-sealing," Kramer said.

"No," Gordon said, "but it'll add thickness to the glass and spread the stress."

"Right," Stern said.

The technicians had put balloons in all the tanks, and capped them. Now they were waiting for the glue to harden. Gordon glanced at his watch. "Three more minutes."

"And then how long for each tank?"

"Six minutes. But we can do two tanks at a time."

Kramer sighed. "Eighteen minutes. Cutting it close."

"We'll make it," Gordon said. "We can always pump the water faster."

"Won't that stress the tanks more?"

"Yes. But we can do it, if we have to."

Kramer looked back at the monitor, where the field was undulating. But the peaks were clearer now. She said, "Why are the field bucks changing?"

"They're not," Gordon said without looking back.

"Yes," she said. "They are. The spikes are getting smaller."

"Smaller?"

Gordon came over to look. He frowned as he stared at the screen. There were four peaks, then three, then two. Then four again, briefly. "Remember, what you're seeing is really a probability function," he said. "Field amplitudes reflect the probability that the event will take place."

"In English?"

Gordon stared at the screen. "Something must have gone wrong back there. And whatever it is, it's changed the probability that they will return."

00:15:02

Chris was sweating. He grunted as he flopped the soldier's inert body onto its back, and resumed his search. He'd spent frantic minutes going through the maroon-and-gray uniforms of two of the dead soldiers, trying to find the key. The surcoats were long, and underneath that, the soldiers wore quilted shirts; all in all, a lot of cloth. Not that the key could be easily concealed; Chris knew that the cage padlock would require a key several inches long, and made of iron.

But Chris didn't find it. Not on the first soldier, and not on the second. Swearing, he got to his feet.

Across the dungeon, Arnaut was still fighting with Oliver; the clang of their swords continued ceaselessly, a steady metallic rhythm. Marek was walking along the walls, holding a torch, searching the dark corners of the dungeon. But he didn't seem to be having success, either.

Chris could almost hear the clock ticking in his head. He looked around, wondering where a key could be hidden. Unfortunately, he realized, it could be almost anywhere: hanging on a wall, or tucked into the base of a torch holder. He went over to the winch and looked around the mechanism. And there he found it  -  a large iron key, at the foot of the winch. "Got it!"

Marek looked up, glanced at his wrist counter as Chris hurried over to the cage to insert the key. The key went right in, but it wouldn't turn. At first he thought the mechanism was stuck, but after thirty agonizing seconds of effort, he was forced to conclude that this was not the key, after all. Feeling helpless and angry, he flung the key to the ground. He turned to the Professor, locked behind the bars.

"I'm sorry," Chris said. "I'm really sorry."

As always, the Professor was unruffled. "I've been thinking, Chris," he said, "about exactly what happened."

"Uh-huh . . ."

"And I think Oliver had it," the Professor said. "He locked me in himself. I think he kept the key."

"Oliver?"

Across the room, Oliver continued to fight, although he was now obviously losing. Arnaut was a better swordsman, and Oliver was drunk and winded. Smiling grimly, Arnaut drove Oliver back with measured blows to the edge of the pit. There Oliver, gasping and sweating, leaned on the railing, too exhausted to continue.

Arnaut gently put the point of his sword to Oliver's neck. "Mercy," Oliver said, panting. "I beg mercy." But it was clear that he did not expect it. Arnaut slowly pressed harder with the sword. Oliver coughed.

"My Lord Arnaut," Marek said, stepping forward. "We need the key to the cage."

"Eh? Key? To the cage?"

Gasping, Oliver smiled. "I know where it lies."

Arnaut jabbed with the sword. "Tell us."

Oliver shook his head. "Never."

"If you tell us," Arnaut said, "I shall spare your life."

At this, Oliver glanced up sharply. "Certes?"

"I am no treacherous, two-faced Englishman," Arnaut said. "Give us the key, and I swear as a true gentle of France that I shall not kill you."

Panting, Oliver stared at Arnaut for several seconds. Finally he stood once again and said, "Very well." He threw away his sword, reached under his robe, and brought out a heavy iron key. Marek took it.

Oliver turned back to Arnaut. "So: I have done my part. Are you a man of your word?"

"In deed," Arnaut said, "I shall not kill you . . ." He moved forward swiftly, and clasped Oliver's knees. "I shall bathe you."

And he flipped Oliver bodily over the rail, into the pit. Oliver landed with a splash in the black water below; he came up sputtering. Cursing, he swam to the side of the pit and reached toward the rocks to get a handhold. But the rocks that lined the pit were dark with slime. Oliver's hands slipped off. He could get no purchase. He treaded water, slapping ineffectually at the surface. He looked up at Arnaut, and swore.

Arnaut said, "Do you swim well?"

"Very well, you son of a French pig."

"Good," Arnaut said. "Then your bath will take some time."

And he turned away from the pit. With a nod to Chris and Marek, he said, "I am in your debt. May God grant you mercy all your days." And then he ran quickly away to rejoin the battle. They heard his footsteps fading.

Marek unlocked the padlock, and the cage door creaked open. The Professor stepped out. He said, "Time?"

"Eleven minutes," Marek said.

They hurried out of the dungeon. Marek was hobbling, but he managed to move quickly. Behind them, they heard Oliver splashing in the water.

"Arnaut!" Oliver cried, his voice echoing from the dark stone walls. "Arnaut!"

00:09:04

The big screens at the far end of the control room showed the technicians filling the shields with water. The shields were holding up fine. But nobody in the control room was looking at the shields. Instead, they stared silently at the console monitor, watching the undulations of the shimmering, computer-generated field. During the last ten minutes, the peaks had become steadily lower, until now they had nearly vanished; when they appeared at all, they were just occasional ripples in the surface.

Still, they watched.

For a moment, the ripples seemed to grow stronger, more definite. "Is something happening?" Kramer said hopefully.

Gordon shook his head. "I don't think so. I think that's just random fluctuations."

"I thought it might be getting stronger," Kramer said.

But Stern could see it wasn't true. Gordon was right; the change was just random. The ripples on the screen remained intermittent, unstable.

"Whatever the problem is back there," Gordon said, "they still have it."

00:05:30

Through the flames that leapt up in the central courtyard of La Roque, Kate saw the Professor and the others come out of a far doorway. She ran to join them. They all seemed to be okay. The Professor nodded to her. They were all moving fast.

Kate said to Chris, "Do you have the ceramic?"

"Yes. I have it." He brought it out of his pocket, turned it to press the button.

"There's not enough space."

"There's space . . . ," Chris said.

"No. You need two meters on all sides, remember?"

They were surrounded by fire. "You won't find that anywhere in this courtyard," Marek said.

"That's right," the Professor said. "We have to go to the next courtyard."

Kate looked ahead. The gatehouse leading to the outer courtyard was forty yards away. But within the gatehouse, the portcullis was up. In fact, it didn't look as if the gate was guarded at all; the soldiers had all abandoned it, to fight the intruders.

"How much time?"

"Five minutes."

"Okay," the Professor said. "Let's get moving."

They moved at a trot through the fiery courtyard, sidestepping flames and battling soldiers. The Professor and Kate were in the lead. Marek, wincing with the pain in his leg, followed behind. And Chris, worried about Marek, brought up the rear.

Kate reached the first gate. There were no guards at all. They ran through the gate, passing beneath the spikes of the raised portcullis. They entered the middle courtyard. "Oh no," Kate said.

All of Oliver's soldiers were garrisoned in the middle court, and there seemed to be hundreds of knights and pages running back and forth, shouting to the men on the battlements, carrying weapons and provisions.

"No room here," the Professor said. "We'll have to go through the next gate. Outside the castle."

"Outside?" Kate said. "We'll never even get across this courtyard."

Marek came hobbling up, panting. He took one look at the courtyard and said, "Hoarding."

"Yes," the Professor said, nodding. He pointed up at the walls. "The hoarding."

The hoarding was the enclosed wooden passageway built along the outside rim of the walls. It was a covered fighting platform that enabled soldiers to shoot down at attacking troops. They might be able to move along the hoarding and make their way to the far side of the courtyard, and the far gatehouse.

Marek said, "Where's Chris?"

They looked back into the central courtyard.

They didn't see him anywhere.

Chris had been following Marek, thinking that perhaps he would have to carry Marek and wondering whether he could, when suddenly he was shoved to one side, slammed bodily against a wall. He heard a voice behind him say in perfect English, "Not you, pal. You stay here." And he felt the point of a sword jabbed in his back.

He turned to see Robert de Kere standing in front of him, holding his sword. De Kere grabbed him roughly by the collar, shoved him against another wall. Chris saw with alarm that they were just outside the arsenal. With the courtyard in flames, this was not the place to be.

De Kere didn't seem to care. He smiled. "In fact," he said, "none of you bastards are going anywhere."

"Why is that?" Chris said, keeping his eye on the sword.

"Because you have their marker, pal."

"No I don't."

"I can hear your transmissions, remember?" De Kere held out his hand. "Come on, give it to me."

He grabbed Chris again, and shoved him through the door. Chris stumbled into the arsenal. It was empty now, the soldiers having fled. All around him were stacked bags of gunpowder. The basins where the soldiers had been grinding still lay on the floor.

"Your fucking Professor," de Kere said, seeing the bowls. "Think you know so much. Give it to me."

Chris fumbled under his doublet, reaching for his pouch.

De Kere snapped his fingers impatiently. "Come on, come on, hurry up."

"Just a minute," Chris said.

"You guys are all the same," de Kere said. "Just like Doniger. You know what Doniger said? Don't worry, Rob, we're making new technology that will fix you up. It's always new technology that will fix you up. But he didn't make any new technology. He never intended to. He was just lying, the way he always does. My goddamn face." He touched the scar that ran down the center. "It hurts all the time. Something about the bones. It aches. And my insides are screwed up. Hurts."

De Kere held out his palm irritably. "Come on. You keep this up, and I'll kill you now."

Chris felt his fingers close around the canister. How far away would the gas work? Not at the distance of a sword. But there was no alternative.

Chris took a deep breath, and sprayed the gas. De Kere coughed, more irritated than surprised, and stepped forward. "You asshole," he said. "You think that's a bright idea? Real tricky. Tricky boy."

He poked at Chris with the sword, jabbing him backward. Chris backed up.

"For that, I'm going to cut you open and let you watch your guts spill out." And he swung upward, but Chris dodged it easily, and he thought, It's had some effect. He sprayed again, closer to de Kere's face, then ducked as the sword swung and struck the floor, knocking over one of the basins.

De Kere wobbled, but he was still on his feet. Chris sprayed a third time, and de Kere somehow remained standing. He swung, the blade hissing; Chris dodged it, but the blade sliced his arm above the right elbow. Blood dripped from the wound, spattering on the floor. The canister fell from his hand.