Elizabeth nodded. She and her team had used the Internet to identify the painting, which Sinskey had been surprised to learn was a Botticelli, a painter best known for his bright, idealized masterpieces Birth of Venus and Springtime. Sinskey loved both of those works despite the fact that they portrayed fertility and the creation of life, which only served to remind her of her own tragic inability to conceive — the lone significant regret in her otherwise very productive life.

“I was hoping,” Sinskey said, “that you could tell me about the symbolism hidden in this painting.”

Langdon looked irritated for the first time all night. “Is that why you called me in? I thought you said it was an emergency.”

“Humor me.”

Langdon heaved a patient sigh. “Dr. Sinskey, generally speaking, if you want to know about a specific painting, you should contact the museum that contains the original. In this case, that would be the Vatican’s Biblioteca Apostolica. The Vatican has a number of superb iconographers who—”

“The Vatican hates me.”

Langdon gave her a startled look. “You, too? I thought I was the only one.”

She smiled sadly. “The WHO feels strongly that the widespread availability of contraception is one of the keys to global health — both to combat sexually transmitted diseases like AIDS and also for general population control.”

“And the Vatican feels differently.”

“Quite. They have spent enormous amounts of energy and money indoctrinating third-world countries into a belief in the evils of contraception.”

“Ah, yes,” Langdon said with a knowing smile. “Who better than a bunch of celibate male octogenarians to tell the world how to have sex?”

Sinskey was liking the professor more and more every second.

She shook the cylinder to recharge it and then projected the image on the wall again. “Professor, take a closer look.”

Langdon walked toward the image, studying it, still moving closer. Suddenly he stopped short. “That’s strange. It’s been altered.”

That didn’t take him long. “Yes, it has, and I want you to tell me what the alterations mean.”

Langdon fell silent, scanning the entire image, pausing to take in the ten letters that spelled catrovacer … and then the plague mask … and also the strange quote around the border about “the eyes of death.”

“Who did this?” Langdon demanded. “Where did it come from?”

“Actually, the less you know right now the better. What I’m hoping is that you’ll be able to analyze these alterations and tell us what they mean.” She motioned to a desk in the corner.

“Here? Right now?”

She nodded. “I know it’s an imposition, but I can’t stress enough how important this is to us.” She paused. “It could well be a matter of life and death.”

Langdon studied her with concern. “Deciphering this may take a while, but I suppose if it’s that important to you—”

“Thank you,” Sinskey interjected before he could change his mind. “Is there anyone you need to call?”

Langdon shook his head and told her he had been planning on a quiet weekend alone.

Perfect. Sinskey got him settled at his desk with the projector, paper, pencil, and a laptop with a secure satellite connection. Langdon looked deeply puzzled about why the WHO would be interested in a modified painting by Botticelli, but he dutifully set to work.

Dr. Sinskey imagined he might end up studying the image for hours with no breakthrough, and so she settled in to get some work of her own done. From time to time she could hear him shaking the projector and scribbling on his notepad. Barely ten minutes had passed when Langdon set down his pencil and announced, “Cerca trova.”

Sinskey glanced over. “What?”

“Cerca trova,” he repeated. “Seek and ye shall find. That’s what this code says.”

Sinskey hurried over and sat down close beside him, listening with fascination as Langdon explained how the levels of Dante’s inferno had been scrambled, and that, when they were replaced in their proper sequence, they spelled the Italian phrase cerca trova.

Seek and find? Sinskey wondered. That’s this lunatic’s message to me? The phrase sounded like a direct challenge. The disturbing memory of the madman’s final words to her during their meeting at the Council on Foreign Relations replayed in her mind: Then it appears our dance has begun.

“You just went white,” Langdon said, studying her thoughtfully. “I take it this is not the message you were hoping for?”

Sinskey gathered herself, straightening the amulet on her neck. “Not exactly. Tell me … do you believe this map of hell is suggesting I seek something?”

“Yes. Cerca trova.”

“And does it suggest where I seek?”

Langdon stroked his chin as other WHO staff began gathering around, looking eager for information. “Not overtly … no, although I’ve got a pretty good idea where you’ll want to start.”

“Tell me,” Sinskey demanded, more forcefully than Langdon would have expected.

“Well, how do you feel about Florence, Italy?”

Sinskey set her jaw, doing her best not to react. Her staff members, however, were less controlled. All of them exchanged startled glances. One grabbed a phone and placed a call. Another hurried through a door toward the front of the plane.

Langdon looked bewildered. “Was it something I said?”

Absolutely, Sinskey thought. “What makes you say Florence?”

“Cerca trova,” he replied, quickly recounting a long-standing mystery involving a Vasari fresco at the Palazzo Vecchio.

Florence it is, Sinskey thought, having heard enough. Obviously, it could not be mere coincidence that her nemesis had jumped to his death not more than three blocks from the Palazzo Vecchio in Florence.

“Professor,” she said, “when I showed you my amulet earlier and called it a caduceus, you paused, as if you wanted to say something, but then you hesitated and seemed to change your mind. What were you going to say?”

Langdon shook his head. “Nothing. It’s foolish. Sometimes the professor in me can be a little overbearing.”

Sinskey stared into his eyes. “I ask because I need to know I can trust you. What were you going to say?”

Langdon swallowed and cleared his throat. “Not that it matters, but you said your amulet is the ancient symbol of medicine, which is correct. But when you called it a caduceus, you made a very common mistake. The caduceus has two snakes on the staff and wings at the top. Your amulet has a single snake and no wings. Your symbol is called—”

“The Rod of Asclepius.”

Langdon cocked his head in surprise. “Yes. Exactly.”

“I know. I was testing your truthfulness.”

“I’m sorry?”

“I was curious to know if you would tell me the truth, no matter how uncomfortable it might make me.”

“Sounds like I failed.”

“Don’t do it again. Total honesty is the only way you and I will be able to work together on this.”

“Work together? Aren’t we done here?”

“No, Professor, we’re not done. I need you to come to Florence to help me find something.”

Langdon stared in disbelief. “Tonight?”

“I’m afraid so. I have yet to tell you about the truly critical nature of this situation.”

Langdon shook his head. “It doesn’t matter what you tell me. I don’t want to fly to Florence.”

“Neither do I,” she said grimly. “But unfortunately our time is running out.”

The noon sun glinted off the sleek roof of Italy’s high-velocity Frecciargento train as it raced northward, cutting a graceful arc across the Tuscan countryside. Despite traveling away from Florence at 174 miles per hour, the “silver arrow” train made almost no noise, its soft repetitive clicking and gently swaying motion having an almost soothing effect on those who rode it.