Although the key barely had entered Sophie’s thoughts through the years, her work in the intelligence community had taught her plenty about security, and now the key’s peculiar tooling no longer looked so mystifying. A laser-tooled varying matrix. Impossible to duplicate. Rather than teeth that moved tumblers, this key’s complex series of laser-burned pockmarks was examined by an electric eye. If the eye determined that the hexagonal pockmarks were correctly spaced, arranged, and rotated, then the lock would open.

Sophie could not begin to imagine what a key like this opened, but she sensed Robert would be able to tell her. After all, he had described the key’s embossed seal without ever seeing it. The cruciform on top implied the key belonged to some kind of Christian organization, and yet Sophie knew of no churches that used laser- tooled varying matrix keys.

Besides, my grandfather was no Christian….

Sophie had witnessed proof of that ten years ago. Ironically, it had been another key—a far more normal one—that had revealed his true nature to her.

The afternoon had been warm when she landed at Charles de Gaulle Airport and hailed a taxi home. Grand-père will be so surprised to see me, she thought. Returning from graduate school in Britain for spring break a few days early, Sophie couldn’t wait to see him and tell him all about the encryption methods she was studying.

When she arrived at their Paris home, however, her grandfather was not there. Disappointed, she knew he had not been expecting her and was probably working at the Louvre. But it’s Saturday afternoon, she realized. He seldom worked on weekends. On weekends, he usually—

Grinning, Sophie ran out to the garage. Sure enough, his car was gone. It was the weekend. Jacques Saunière despised city driving

and owned a car for one destination only—his vacation château in Normandy, north of Paris. Sophie, after months in the congestion of London, was eager for the smells of nature and to start her vacation right away. It was still early evening, and she decided to leave immediately and surprise him. Borrowing a friend’s car, Sophie drove north, winding into the deserted moon-swept hills near Creully. She arrived just after ten o’clock, turning down the long private driveway toward her grandfather’s retreat. The access road was over a mile long, and she was halfway down it before she could start to see the house through the trees—a mammoth, old stone château nestled in the woods on the side of a hill.

Sophie had half expected to find her grandfather asleep at this hour and was excited to see the house twinkling with lights. Her delight turned to surprise, however, when she arrived to find the driveway filled with parked cars—Mercedeses, BMWs, Audis, and a Rolls-Royce.

Sophie stared a moment and then burst out laughing. My grand- père, the famous recluse! Jacques Saunière, it seemed, was far less reclusive than he liked to pretend. Clearly he was hosting a party while Sophie was away at school, and from the looks of the automobiles, some of Paris’s most influential people were in attendance.

Eager to surprise him, she hurried to the front door. When she got there, though, she found it locked. She knocked. Nobody answered. Puzzled, she walked around and tried the back door. It too was locked. No answer.

Confused, she stood a moment and listened. The only sound she heard was the cool Normandy air letting out a low moan as it swirled through the valley.

No music. No voices. Nothing.

In the silence of the woods, Sophie hurried to the side of the house and clambered up on a woodpile, pressing her face to the living room window. What she saw inside made no sense at all.

“Nobody’s here!”

The entire first floor looked deserted.

Where are all the people?

Heart racing, Sophie ran to the woodshed and got the spare key her grandfather kept hidden under the kindling box. She ran to the front door and let herself in. As she stepped into the deserted foyer, the control panel for the security system started blinking red—a warning that the entrant had ten seconds to type the proper code before the security alarms went off.

He has the alarm on during a party?

Sophie quickly typed the code and deactivated the system.

Entering, she found the entire house uninhabited. Upstairs too. As she descended again to the deserted living room, she stood a moment in the silence, wondering what could possibly be happening.

It was then that Sophie heard it.

Muffled voices. And they seemed to be coming from underneath her. Sophie could not imagine. Crouching, she put her ear to the floor and listened. Yes, the sound was definitely coming from below. The voices seemed to be singing, or … chanting? She was frightened. Almost more eerie than the sound itself was the realization that this house did not even have a basement.

At least none I’ve ever seen.

Turning now and scanning the living room, Sophie’s eyes fell to the only object in the entire house that seemed out of place—her grandfather’s favorite antique, a sprawling Aubusson tapestry. It usually hung on the east wall beside the fireplace, but tonight it had been pulled aside on its brass rod, exposing the wall behind it.

Walking toward the bare wooden wall, Sophie sensed the chanting getting louder. Hesitant, she leaned her ear against the wood. The voices were clearer now. People were definitely chanting … intoning words Sophie could not discern.

The space behind this wall is hollow!

Feeling around the edge of the panels, Sophie found a recessed fingerhold. It was discreetly crafted. A sliding door. Heart pounding, she placed her finger in the slot and pulled it. With noiseless

precision, the heavy wall slid sideways. From out of the darkness beyond, the voices echoed up.

Sophie slipped through the door and found herself on a rough- hewn stone staircase that spiraled downward. She’d been coming to this house since she was a child and yet had no idea this staircase even existed!

As she descended, the air grew cooler. The voices clearer. She heard men and women now. Her line of sight was limited by the spiral of the staircase, but the last step was now rounding into view. Beyond it, she could see a small patch of the basement floor—stone, illuminated by the flickering orange blaze of firelight.

Holding her breath, Sophie inched down another few steps and crouched down to look. It took her several seconds to process what she was seeing.

The room was a grotto—a coarse chamber that appeared to have been hollowed from the granite of the hillside. The only light came from torches on the walls. In the glow of the flames, thirty or so people stood in a circle in the center of the room.

I’m dreaming, Sophie told herself. A dream. What else could this be?

Everyone in the room was wearing a mask. The women were dressed in white gossamer gowns and golden shoes. Their masks were white, and in their hands they carried golden orbs. The men wore long black tunics, and their masks were black. They looked like pieces in a giant chess set. Everyone in the circle rocked back and forth and chanted in reverence to something on the floor before them … something Sophie could not see.

The chanting grew steady again. Accelerating. Thundering now. Faster. The participants took a step inward and knelt. In that instant, Sophie could finally see what they all were witnessing. Even as she staggered back in horror, she felt the image searing itself into her memory forever. Overtaken by nausea, Sophie spun, clutching at the stone walls as she clambered back up the stairs. Pulling the door closed, she fled the deserted house, and drove in a tearful stupor back to Paris.

That night, with her life shattered by disillusionment and betrayal, she packed her belongings and left her home. On the dining room

table, she left a note.

I WAS THERE. DON’T TRY TO FIND ME.

Beside the note, she laid the old spare key from the château’s woodshed.

“Sophie!” Langdon’s voice intruded. “Stop! Stop!

Emerging from the memory, Sophie slammed on the brakes, skidding to a halt. “What? What happened?!”

Langdon pointed down the long street before them.

When she saw it, Sophie’s blood went cold. A hundred yards ahead, the intersection was blocked by a couple of DCPJ police cars, parked askew, their purpose obvious. They’ve sealed off Avenue Gabriel!

Langdon gave a grim sigh. “I take it the embassy is off-limits this evening?”

Down the street, the two DCPJ officers who stood beside their cars were now staring in their direction, apparently curious about the headlights that had halted so abruptly up the street from them.

Okay, Sophie, turn around very slowly.

Putting the SmartCar in reverse, she performed a composed three- point turn and reversed her direction. As she drove away, she heard the sound of squealing tires behind them. Sirens blared to life.

Cursing, Sophie slammed down the accelerator.

CHAPTER 33

Sophie’s SmartCar tore through the diplomatic quarter, weaving past embassies and consulates, finally racing out a side street and taking a right turn back onto the massive thoroughfare of Champs- Elysées.

Langdon sat white-knuckled in the passenger seat, twisted backward, scanning behind them for any signs of the police. He suddenly wished he had not decided to run. You didn’t, he reminded himself. Sophie had made the decision for him when she threw the GPS dot out the bathroom window. Now, as they sped away from the embassy, serpentining through sparse traffic on Champs-Elysées, Langdon felt his options deteriorating. Although Sophie seemed to have lost the police, at least for the moment, Langdon doubted their luck would hold for long.

Behind the wheel Sophie was fishing in her sweater pocket. She removed a small metal object and held it out for him. “Robert, you’d better have a look at this. This is what my grandfather left me behind Madonna of the Rocks.”

Feeling a shiver of anticipation, Langdon took the object and examined it. It was heavy and shaped like a cruciform. His first instinct was that he was holding a funeral pieu—a miniature version of a memorial spike designed to be stuck into the ground at a gravesite. But then he noted the shaft protruding from the cruciform was prismatic and triangular. The shaft was also pockmarked with hundreds of tiny hexagons that appeared to be finely tooled and scattered at random.

“It’s a laser-cut key,” Sophie told him. “Those hexagons are read by an electric eye.”

A key? Langdon had never seen anything like it.

“Look at the other side,” she said, changing lanes and sailing through an intersection.

When Langdon turned the key, he felt his jaw drop. There, intricately embossed on the center of the cross, was a stylized fleur-

de-lis with the initials P.S.! “Sophie,” he said, “this is the seal I told you about! The official device of the Priory of Sion.”

She nodded. “As I told you, I saw the key a long time ago. He told me never to speak of it again.”

Langdon’s eyes were still riveted on the embossed key. Its high- tech tooling and age-old symbolism exuded an eerie fusion of ancient and modern worlds.

“He told me the key opened a box where he kept many secrets.” Langdon felt a chill to imagine what kind of secrets a man like

Jacques Saunière might keep. What an ancient brotherhood was doing with a futuristic key, Langdon had no idea. The Priory existed for the sole purpose of protecting a secret. A secret of incredible power. Could this key have something to do with it? The thought was overwhelming. “Do you know what it opens?”

Sophie looked disappointed. “I was hoping you knew.”

Langdon remained silent as he turned the cruciform in his hand, examining it.

“It looks Christian,” Sophie pressed.

Langdon was not so sure about that. The head of this key was not the traditional long-stemmed Christian cross but rather was a square cross—with four arms of equal length—which predated Christianity by fifteen hundred years. This kind of cross carried none of the Christian connotations of crucifixion associated with the longer- stemmed Latin Cross, originated by Romans as a torture device. Langdon was always surprised how few Christians who gazed upon “the crucifix” realized their symbol’s violent history was reflected in its very name: “cross” and “crucifix” came from the Latin verb cruciare—to torture.

“Sophie,” he said, “all I can tell you is that equal-armed crosses like this one are considered peaceful crosses. Their square configurations make them impractical for use in crucifixion, and their balanced vertical and horizontal elements convey a natural union of male and female, making them symbolically consistent with Priory philosophy.”

She gave him a weary look. “You have no idea, do you?” Langdon frowned. “Not a clue.”

“Okay, we have to get off the road.” Sophie checked her rearview mirror. “We need a safe place to figure out what that key opens.”

Langdon thought longingly of his comfortable room at the Ritz. Obviously, that was not an option. “How about my hosts at the American University of Paris?”

“Too obvious. Fache will check with them.” “You must know people. You live here.”

“Fache will run my phone and e-mail records, talk to my coworkers. My contacts are compromised, and finding a hotel is no good because they all require identification.”

Langdon wondered again if he might have been better off taking his chances letting Fache arrest him at the Louvre. “Let’s call the embassy. I can explain the situation and have the embassy send someone to meet us somewhere.”

“Meet us?” Sophie turned and stared at him as if he were crazy. “Robert, you’re dreaming. Your embassy has no jurisdiction except on their own property. Sending someone to retrieve us would be considered aiding a fugitive of the French government. It won’t happen. If you walk into your embassy and request temporary asylum, that’s one thing, but asking them to take action against French law enforcement in the field?” She shook her head. “Call your embassy right now, and they are going to tell you to avoid further damage and turn yourself over to Fache. Then they’ll promise to pursue diplomatic channels to get you a fair trial.” She gazed up the line of elegant storefronts on Champs-Elysées. “How much cash do you have?”

Langdon checked his wallet. “A hundred dollars. A few euro.

Why?”

“Credit cards?” “Of course.”

As Sophie accelerated, Langdon sensed she was formulating a plan. Dead ahead, at the end of Champs-Elysées, stood the Arc de Triomphe—Napoleon’s 164-foot-tall tribute to his own military potency—encircled by France’s largest rotary, a nine-lane behemoth. Sophie’s eyes were on the rearview mirror again as they approached the rotary. “We lost them for the time being,” she said,

“but we won’t last another five minutes if we stay in this car.”