Vittoria scowled. "Are questions bad?"

Not many children could say they remembered the day they met their father, but Vittoria Vetra could. She was eight years old, living where she always had, Orfanotrofio di Siena, a Catholic orphanage near Florence, deserted by parents she never knew. It was raining that day. The nuns had called for her twice to come to dinner, but as always she pretended not to hear. She lay outside in the courtyard, staring up at the raindrops… feeling them hit her body… trying to guess where one would land next. The nuns called again, threatening that pneumonia might make an insufferably headstrong child a lot less curious about nature.

"They say you ask a lot of questions," the young man said.

I can't hear you, Vittoria thought.

She was soaked to the bone when the young priest came out to get her. She didn't know him. He was new there. Vittoria waited for him to grab her and drag her back inside. But he didn't. Instead, to her wonder, he lay down beside her, soaking his robes in a puddle.

He laughed. "Guess they were right."

Vittoria sat up. "What's gravity?" she demanded. "Tell me!"

"I'm not wondering why they fall! I already know!"

The priest gave her an astonished look. "You do?"

"Sister Francisca says raindrops are angels" tears coming down to wash away our sins."

"No."

The priest shrugged sadly. "Too bad. Gravity answers a lot of questions."

"What are you doing out here?"

"It must be what?"

The young priest was Leonardo Vetra. Although he had been an award-winning physics student while in university, he'd heard another call and gone into the seminary. Leonardo and Vittoria became unlikely best friends in the lonely world of nuns and regulations. Vittoria made Leonardo laugh, and he took her under his wing, teaching her that beautiful things like rainbows and the rivers had many explanations. He told her about light, planets, stars, and all of nature through the eyes of both God and science. Vittoria's innate intellect and curiosity made her a captivating student. Leonardo protected her like a daughter.

"No it doesn't!" the girl fired back. "Raindrops fall because everything falls! Everything falls! Not just rain!"

"Wow!" he said, sounding amazed. "So that explains it."

"Same thing you're doing… wondering why raindrops fall."

The priest scratched his head, looking perplexed. "You know, young lady, you're right. Everything does fall. It must be gravity."

He gave her an astonished look. "You haven't heard of gravity?"

The priest gave her a wink. "What do you say I tell you over dinner."

"Physics?" Vittoria cried. "I thought you loved God!"

Vittoria was happy too. She had never known the joy of having a father. When every other adult answered her questions with a slap on the wrist, Leonardo spent hours showing her books. He even asked what her ideas were. Vittoria prayed Leonardo would stay with her forever. Then one day, her worst nightmare came true. Father Leonardo told her he was leaving the orphanage.

"I do, very much. Which is why I want to study his divine rules. The laws of physics are the canvas God laid down on which to paint his masterpiece."

"I'm moving to Switzerland," Leonardo said. "I have a grant to study physics at the University of Geneva."

Vittoria was devastated. But Father Leonardo had some other news. He told Vittoria he had spoken to his superiors, and they said it was okay if Father Leonardo adopted her.

Father Leonardo told her.

"Would you like me to adopt you?" Leonardo asked.

"What's adopt mean?" Vittoria said.

Vittoria hugged him for five minutes, crying tears of joy. "Oh yes! Yes!"

Vittoria Vetra's body felt numb as she strode down the LHC tunnel. She saw her muted reflection in the LHC and sensed her father's absence. Normally she existed in a state of deep calm, in harmony with the world around her. But now, very suddenly, nothing made sense. The last three hours had been a blur.

Leonardo told her he had to leave for a while and get their new home settled in Switzerland, but he promised to send for her in six months. It was the longest wait of Vittoria's life, but Leonardo kept his word. Five days before her ninth birthday, Vittoria moved to Geneva. She attended Geneva International School during the day and learned from her father at night.

It had been 10A. M. in the Balearic Islands when Kohler's call came through. Your father has been murdered. Come home immediately. Despite the sweltering heat on the deck of the dive boat, the words had chilled her to the bone, Kohler's emotionless tone hurting as much as the news.

Three years later Leonardo Vetra was hired by CERN. Vittoria and Leonardo relocated to a wonderland the likes of which the young Vittoria had never imagined.

Deep breaths, she told herself, but she couldn't calm her mind. The questions circled faster and faster. Who killed her father? And why? Who was this American "specialist"? Why was Kohler insisting on seeing the lab?

Kohler had said there was evidence that her father's murder was related to the current project. What evidence? Nobody knew what we were working on! And even if someone found out, why would they kill him?

Now she had returned home. But home to what? CERN, her world since she was twelve, seemed suddenly foreign. Her father, the man who had made it magical, was gone.

As she moved down the LHC tunnel toward her father's lab, Vittoria realized she was about to unveil her father's greatest achievement without him there. She had pictured this moment much differently. She had imagined her father calling CERN's top scientists to his lab, showing them his discovery, watching their awestruck faces. Then he would beam with fatherly pride as he explained to them how it had been one of Vittoria's ideas that had helped him make the project a reality… that his daughter had been integral in his breakthrough. Vittoria felt a lump in her throat. My father and I were supposed to share this moment together. But here she was alone. No colleagues. No happy faces. Just an American stranger and Maximilian Kohler.

The entry to Leonardo Vetra's lab was a long sterile hallway paved entirely in white tile. Langdon felt like he was entering some kind of underground insane asylum. Lining the corridor were dozens of framed, black-and-white images. Although Langdon had made a career of studying images, these were entirely alien to him. They looked like chaotic negatives of random streaks and spirals. Modern art? he mused. Jackson Pollock on amphetamines?

Genius, she thought. My father… Dad. Dead.

"Scatter plots," Vittoria said, apparently noting Langdon's interest. "Computer representations of particle collisions. That's the Z-particle," she said, pointing to a faint track that was almost invisible in the confusion. "My father discovered it five years ago. Pure energy -- no mass at all. It may well be the smallest building block in nature. Matter is nothing but trapped energy."

Even as a child, Vittoria had disliked the man. Although she eventually came to respect his potent intellect, his icy demeanor always seemed inhuman, the exact antithesis of her father's warmth. Kohler pursued science for its immaculate logic… her father for its spiritual wonder. And yet oddly there had always seemed to be an unspoken respect between the two men. Genius, someone had once explained to her, accepts genius unconditionally.

Maximilian Kohler. Der Kцnig.

"Vittoria," Kohler said, as they approached the lab's imposing steel door, "I should mention that I came down here this morning looking for your father."

Matter is energy? Langdon cocked his head. Sounds pretty Zen. He gazed at the tiny streak in the photograph and wondered what his buddies in the Harvard physics department would say when he told them he'd spent the weekend hanging out in a Large Hadron Collider admiring Z-particles.

Vittoria flushed slightly. "You did?"

"Yes. And imagine my surprise when I discovered he had replaced CERN's standard keypad security with something else." Kohler motioned to an intricate electronic device mounted beside the door.

"I apologize," she said. "You know how he was about privacy. He didn't want anyone but the two of us to have access."

Langdon was in no way prepared for what happened next.

Kohler said, "Fine. Open the door."

Vittoria stood a long moment. Then, pulling a deep breath, she walked to the mechanism on the wall.

Vittoria stepped up to the device and carefully aligned her right eye with a protruding lens that looked like a telescope. Then she pressed a button. Inside the machine, something clicked. A shaft of light oscillated back and forth, scanning her eyeball like a copy machine.

Robert Langdon stood in horrified revelation. The image of Leonardo Vetra came back in grisly detail -- the bloody face, the solitary hazel eye staring back, and the empty eye socket. He tried to reject the obvious truth, but then he saw it… beneath the scanner on the white tile floor… faint droplets of crimson. Dried blood.

Vittoria, thankfully, did not notice.

"It's a retina scan," she said. "Infallible security. Authorized for two retina patterns only. Mine and my father's."

Kohler fixed Langdon with an adamant stare. His message was clear: As I told you… the missing eye serves a higher purpose.

The steel door slid open and she walked through.