or several seconds, Langdon stared in wonder at the photograph of Saunière's postscript. P.S. Find Robert Langdon. He felt as if the floor were tilting beneath his feet. Saunière left a postscript with my name on it? In his wildest dreams, Langdon could not fathom why.

"Now do you understand," Sophie said, her eyes urgent, "why Fache ordered you here tonight, and why you are his primary suspect?"

The only thing Langdon understood at the moment was why Fache had looked so smug when Langdon suggested Saunière would have accused his killer by name.

Find Robert Langdon.

"Why would Saunière write this?" Langdon demanded, his confusion now giving way to anger. "Why would I want to kill Jacques Saunière?"

"Fache has yet to uncover a motive, but he has been recording his entire conversation with you tonight in hopes you might reveal one."

Langdon opened his mouth, but still no words came.

"He's fitted with a miniature microphone," Sophie explained. "It's connected to a transmitter in his pocket that radios the signal back to the command post."

"This is impossible," Langdon stammered. "I have an alibi. I went directly back to my hotel after my lecture. You can ask the hotel desk."

"Fache already did. His report shows you retrieving your room key from the concierge at about ten-thirty. Unfortunately, the time of the murder was closer to eleven. You easily could have left your hotel room unseen."

"This is insanity! Fache has no evidence!"

Sophie's eyes widened as if to say: No evidence? "Mr. Langdon, your name is written on the floor beside the body, and Saunière's date book says you were with him at approximately the time of the murder." She paused. "Fache has more than enough evidence to take you into custody for questioning."

Langdon suddenly sensed that he needed a lawyer. "I didn't do this."

Sophie sighed. "This is not American television, Mr. Langdon. In France, the laws protect the police, not criminals. Unfortunately, in this case, there is also the media consideration. Jacques Saunière was a very prominent and well-loved figure in Paris, and his murder will be news in the morning. Fache will be under immediate pressure to make a statement, and he looks a lot better having a suspect in custody already. Whether or not you are guilty, you most certainly will be held by DCPJ until they can figure out what really happened."

Langdon felt like a caged animal. "Why are you telling me all this?"

"Because, Mr. Langdon, I believe you are innocent." Sophie looked away for a moment and then back into his eyes. "And also because it is partially my fault that you're in trouble."

"I'm sorry? It's your fault Saunière is trying to frame me?"

"Saunière wasn't trying to frame you. It was a mistake. That message on the floor was meant for me."

Langdon needed a minute to process that one. "I beg your pardon?"

"That message wasn't for the police. He wrote it for me. I think he was forced to do everything in such a hurry that he just didn't realize how it would look to the police." She paused. "The numbered code is meaningless. Saunière wrote it to make sure the investigation included cryptographers, ensuring that I would know as soon as possible what had happened to him."

Langdon felt himself losing touch fast. Whether or not Sophie Neveu had lost her mind was at this point up for grabs, but at least Langdon now understood why she was trying to help him. P.S. Find Robert Langdon. She apparently believed the curator had left her a cryptic postscript telling her to find Langdon. "But why do you think his message was for you?"

"The Vitruvian Man," she said flatly. "That particular sketch has always been my favorite Da Vinci work. Tonight he used it to catch my attention."

"Hold on. You're saying the curator knew your favorite piece of art?" She nodded. "I'm sorry. This is all coming out of order. Jacques Saunière and I…"

Sophie's voice caught, and Langdon heard a sudden melancholy there, a painful past, simmering just below the surface. Sophie and Jacques Saunière apparently had some kind of special relationship. Langdon studied the beautiful young woman before him, well aware that aging men in France often took young mistresses. Even so, Sophie Neveu as a "kept woman" somehow didn't seem to fit.

"We had a falling-out ten years ago," Sophie said, her voice a whisper now. "We've barely spoken since. Tonight, when Crypto got the call that he had been murdered, and I saw the images of his body and text on the floor, I realized he was trying to send me a message."

"Because of The Vitruvian Man?"

"Yes. And the letters P.S."

"Post Script?"

She shook her head. "P.S. are my initials."

"But your name is Sophie Neveu."

She looked away. "P.S. is the nickname he called me when I lived with him." She blushed. "It stood for Princesse Sophie"

Langdon had no response.

"Silly, I know," she said. "But it was years ago. When I was a little girl."

"You knew him when you were a little girl?"

"Quite well," she said, her eyes welling now with emotion. "Jacques Saunière was my grandfather."