The Church of Saint-Sulpice, it is said, has the most eccentric history of any building in Paris. Built over the ruins of an ancient temple to the Egyptian goddess Isis, the church possesses an architectural footprint matching that of Notre Dame to within inches. The sanctuary has played host to the baptisms of the Marquis de Sade and Baudelaire, as well as the marriage of Victor Hugo. The attached seminary has a well-documented history of unorthodoxy and was once the clandestine meeting hall for numerous secret societies.

Tonight, the cavernous nave of Saint-Sulpice was as silent as a tomb, the only hint of life the faint smell of incense from mass earlier that evening. Silas sensed an uneasiness in Sister Sandrine’s demeanor as she led him into the sanctuary. He was not surprised by this. Silas was accustomed to people being uncomfortable with his appearance.

«You’re an American,» she said.

«French by birth,» Silas responded. «I had my calling in Spain, and I now study in the United States.»

Sister Sandrine nodded. She was a small woman with quiet eyes. «And you have never seen Saint- Sulpice?»

«I realize this is almost a sin in itself.» «She is more beautiful by day.» «I am certain. Nonetheless, I am grateful that you would provide me this opportunity tonight.» «The abbé requested it. You obviously have powerful friends.» You have no idea, Silas thought.

As he followed Sister Sandrine down the main aisle, Silas was surprised by the austerity of the sanctuary. Unlike Notre Dame with its colorful frescoes, gilded altar-work, and warm wood, Saint- Sulpice was stark and cold, conveying an almost barren quality reminiscent of the ascetic cathedrals of Spain. The lack of decor made the interior look even more expansive, and as Silasgazed up into the soaring ribbed vault of the ceiling, he imagined he was standing beneath the hull of an enormous overturned ship.

A fitting image, he thought. The brotherhood’s ship was about to be capsized forever. Feeling eager to get to work, Silas wished Sister Sandrine would leave him. She was a small woman whom Silas could incapacitate easily, but he had vowed not to use force unless absolutely necessary. She is a woman of the cloth, and it is not her fault the brotherhood chose her church as a hiding place for their keystone.She should not be punished for the sins of others.

«I am embarrassed, Sister, that you were awoken on my behalf.»

«Not at all. You are in Paris a short time. You should not miss Saint-Sulpice. Are your interests in the church more architectural or historical?»

«Actually, Sister, my interests are spiritual.»

She gave a pleasant laugh. «That goes without saying. I simply wondered where to begin your tour.»

Silas felt his eyes focus on the altar. «A tour is unnecessary. You have been more than kind. I can show myself around.»

«It is no trouble,» she said. «After all, I am awake.»

Silas stopped walking. They had reached the front pew now, and the altar was only fifteen yards away. He turned his massive body fully toward the small woman, and he could sense her recoil as she gazed up into his red eyes. «If it does not seem too rude, Sister, I am not accustomed to simply walking into a house of God and taking a tour. Would you mind if I took some time alone to pray before I look around?»

Sister Sandrine hesitated. «Oh, of course. I shall wait in the rear of the church for you.»

Silas put a soft but heavy hand on her shoulder and peered down. «Sister, I feel guilty already for having awoken you. To ask you to stay awake is too much. Please, you should return to bed. I can enjoy your sanctuary and then let myself out.»

She looked uneasy. «Are you sure you won’t feel abandoned?» «Not at all. Prayer is a solitary joy.» «As you wish.» Silas took his hand from her shoulder. «Sleep well, Sister. May the peace of the Lord be with you.» «And also with you.» Sister Sandrine headed for the stairs. «Please be sure the door closes tightly on your way out.»

«I will be sure of it.» Silas watched her climb out of sight. Then he turned and knelt in the front pew, feeling the cilice cut into his leg.

Dear God, I offer up to you this work I do today… .

Crouching in the shadows of the choir balcony high above the altar, Sister Sandrine peered silently through the balustrade at the cloaked monk kneeling alone. The sudden dread in her soul made it hard to stay still. For a fleeting instant, she wondered if this mysterious visitor could be the enemy they had warned her about, and if tonight she would have to carry out the orders she had been holding all these years. She decided to stay there in the darkness and watch his every move.

Emerging from the shadows, Langdon and Sophie moved stealthily up the deserted Grand Gallery corridor toward the emergency exit stairwell.

As he moved, Langdon felt like he was trying to assemble a jigsaw puzzle in the dark. The newest aspect of this mystery was a deeply troubling one: The captain of the Judicial Police is trying to frame me for murder

«Do you think,» he whispered,» that maybe Fache wrote that message on the floor?» Sophie didn’t even turn. «Impossible.» Langdon wasn’t so sure. «He seems pretty intent on making me look guilty. Maybe he thought writing my name on the floor would help his case?»

«The Fibonacci sequence? The P. S. ? All the Da Vinci and goddess symbolism? That had to be my grandfather.»

Langdon knew she was right. The symbolism of the clues meshed too perfectly – the pentacle, TheVitruvian Man, Da Vinci, the goddess, and even the Fibonacci sequence. A coherent symbolic set, as iconographers would call it. All inextricably tied.

«And his phone call to me this afternoon,» Sophie added. «He said he had to tell me something. I’m certain his message at the Louvre was his final effort to tell me something important, something he thought you could help me understand.»

Langdon frowned. O, Draconian devil! Oh, lame saint! He wished he could comprehend the message, both for Sophie’s well-being and for his own. Things had definitely gotten worse since he first laid eyes on the cryptic words. His fake leap out the bathroom window was not going to help Langdon’s popularity with Fache one bit. Somehow he doubted the captain of the French police would see the humor in chasing down and arresting a bar of soap. «The doorway isn’t much farther,» Sophie said.» Do you think there’s a possibility that the numbers in your grandfather’s message hold the key to understanding the other lines?» Langdon had once worked on a series of Baconian manuscripts that contained epigraphical ciphers in which certain lines of code were clues as to how to decipher the other lines.

«I’ve been thinking about the numbers all night. Sums, quotients, products. I don’t see anything. Mathematically, they’re arranged at random. Cryptographic gibberish.»

«And yet they’re all part of the Fibonacci sequence. That can’t be coincidence.»

«It’s not. Using Fibonacci numbers was my grandfather’s way of waving another flag at me – like writing the message in English, or arranging himself like my favorite piece of art, or drawing a pentacle on himself. All of it was to catch my attention.»

«The pentacle has meaning to you?»

«Yes. I didn’t get a chance to tell you, but the pentacle was a special symbol between my grandfather and me when I was growing up. We used to play Tarot cards for fun, and my indicator card always turned out to be from the suit of pentacles. I’m sure he stacked the deck, but pentacles got to be our little joke.»