"His Holiness once told me a pope was a man torn between the real world and the divine. It seems the real world is upon us tonight. I'm familiar with Illuminati lore and the legend of the brandings. La purga is a dark stain on this Church's history. I'm not surprised this ghost has returned to haunt us," the Camerlengo Patrick McKenna said and Langdon seemed a bit surprised. They were all assembled in the grand office, listening to the Camerlengo's voice – a man in his mid-thirties with deep, dark eyes. The kind of priest who often inspires, before the years of dogma catch up with him. He sat behind the massive desk, and if he seemed young before, he seemed like a child now, overcome by the position he's in. But when he spoke to Richter, he's in command. "Commandante, have you begun to search for the explosive device?"

"Of course, but it could be anywhere. My primary concern at the moment is the safety of the cardinals."

"The Sistine Chapel is a fortress. As long as the cardinals are in conclave, your security concerns are at a minimum. Devote as many of our resources…"

"Signori if you're about to suggest a naked-eye search of the entire Vatican City. I will tell you we do not have the people…"

"Commander. Though I am not His Holiness, when you are addressing me you are addressing this office. Do you understand?" the Camerlengo interposed sharply. Again Richter looked quite dumbstruck. "Yes, Father," he said a bit embarrassed. A small smile played across Ernesto's lips and Sara slightly poked him in the side. He looked at her quizzically and an amused smile started to play on her lips as well. Oh she really could get used to this.

"You said the image on the screen was illuminated by artificial light. Might I suggest methodically cutting power to various sections of the city. When the image on the screen goes dark, you'll have a specific idea of the camera's location."

Richter nodded – that indeed was a pretty good idea. The Camerlengo turned to Vittoria. "Dr. Vetra, besides yourself and your research partner, who else knew about this antimatter project?"

"No one but the research team. This project was strictly confidential. But Silvano kept detailed journals. If he told anyone else about what we were doing, he would have made a note."

"Do you have these journals?"

"I can have them flown from Geneva in an hour."

"Please."

Vittoria nodded and instantly fetched her phone out of her pocket to inform her team. The Camerlengo then turned his attention to Robert. "Professor Langdon," he said and indicated him to follow. The others watched as the two men disappeared behind another door. "Mr. Langdon you are correct that I may grant you access to the archives…"

"Thank you, Padre."

"I said that you were correct that I may, not that I will. Christianity's most sacred codices are in that archive. Given your recent entanglements with the Church there is a question I'd like to ask you first, here in the office of His Holiness." While speaking, the Camerlengo slowly made his way towards the professor and came to a halt only a few metres before him. "Do you believe in God, sir?"

"Father, I simply believe that religion…"

"I did not ask if you believe what man says about God. I asked if you believe in God."

Robert paused, thinking deeply about his answer before he spoke. "I'm an academic. My mind tells me I will never understand God."

"And your heart?"

"Tells me I'm not meant to. Faith is a gift that I have yet to receive."

The Camerlengo smiles slightly. Pretty damn good answer. He then puts a hand on Langdon's shoulder and leans in. "Be delicate with our treasures."

"Mi piace lui." [I like him] Sara said as she and Ernesto stood outside at the Belvedere Courtyard waiting for Robert to join them. "Non ho mai saputo che ti interessa la storia dell'arte" [I never knew that you are interested in art history.] Ernesto said and Sara shrugged. "Beh… era una mia piccola passione mentre crescevo. Mammà mi insegnava. Ci sono alcune cose che ancora non sai di me." [It was a little passion of mine while growing up. Mom used to teach me. There are a few things you still don't know about me.] Sara teased. "È così?" [Is that so?] Ernesto then gave her one of his textbook smiles that made her heart flutter. In this brief moment she forgot everything that had happened in the last few hours and the threat that endangered their lives. She took this opportunity to steal a small kiss from her partner. "Pensi che possa farlo?" [You think he can do it] She then wanted to know as the intimate moment had passed. "Lo spero davvero." [I really hope so.]

Sara nodded as Robert came to join them. A moment later they were on their way to the library as Vittoria shouted after them. "Professor Langdon!" They turned down a narrow passageway as Vittoria caught up to them. "If this path really leads to the Church of Illumination that may be where they've hidden the antimatter," she suggested and Robert seemed to light up immediately. "A shining star at the end of the path. I thought so too."

Sara couldn't help but smile slightly. They really didn't spoil two marriages.

"Follow the path. We may find the canister."

"Can you deactivate the device?" Sara interposed.

"I can change the batteries as long as we have more than five minutes. That would give us another 24 hours to get it safely back to CERN."

Sara nodded and they headed along. The officers up front, followed by the two academics. "What are we looking for in the archives?" Vittoria wanted to know.

"A bound volume written by Galileo," Robert answered.

"Galileo was Illuminati?"

"Yeah. And an obedient Catholic who didn't think that Church and science were enemies but a different language telling the same story. He wanted like minds to find the Church of Illumination but he couldn't exactly advertise its location so he created a coded path…"

As they walked up the stairs the light suddenly went off. "Richter has started to turn off the power of various grids. It'll be back on in a minute," Ernesto explained and they continued their way.

"Then some unknown Illuminati master sculpted four statues. Each one a tribute to one of the fundamental elements earth, air, fire, and water and placed the statues out in public in churches throughout Rome. Each statue held a clue pointing to the next," Robert continued. "At the end of the path was the Church of Illumination. If you could find that you were one of them."

"What makes you think he's going to murder in the churches?" Sara wanted to know.

"The Illuminati called those four churches by the special name L'altare della scienza."

"Sacrifice them on the altars of science, he said", Vittoria pondered.

"Exactly."

As they finally came to a halt at the entrance of the archives, Robert's face lit up immediately. "Oh wow. Look at this." Staring up at the impressive façade of the Vatican Archives, he took a deep breath and stepped forward to enter. Ernesto and Sara didn't follow. "We go in alone?" Robert asked in surprise. "Vatican Police aren't allowed access to the archives. Only Swiss Guard. Lt. Chartrand will meet you inside. We'll be here when you're done," Ernesto explained. Langdon turned back to the archives with a look of deep contentment and stepped through the double doors, followed by Vittoria. As soon as they were gone, Sara took a seat at a nearby bench and stretched out her feet. "Come ti senti?"[How do you feel?] Ernesto wanted to know. "Stanco." [Tired]

"Dovresti sdraiarti per un po'…" [You should lie down for a while.] Ernesto suggested but Sara shook her head. "Se vado a dormire ora, non mi sveglierò per un po'. Inoltre, mi farebbe sentire ancora peggio. Sto bene, ho solo bisogno di sedermi." [If I go to sleep now, I won't wake up for a while. Besides, it would make me feel even worse. I'm fine, I just need to sit down.]

The two modern glass doors of the elevator slit open, revealing what looked like a 23rd century library. It's a massive underground space, like a darkened airplane hangar, with a dozen glass boxes evenly spaced throughout. They're lit up from within, each containing row upon row of bookshelves, neatly filled with books, papers, and arcana. Lt. Chartrand, a young member of the Swiss Guard dressed in suit and earpiece, lead Robert and Vittoria toward the glass enclosures. "The chambers are hermetic vaults, oxygen is kept at lowest possible levels. It's a partial vacuum inside. So extended stays are not recommended." Chartrand stopped at one particular chamber and gestured to the sign on its door: Il Processo Galileano. "I'll be just outside the door. Watching you, Mr. Langdon."

The electronic revolving door spins and admits Langdon and Vittoria to the interior of the vault. "By the way, it's normal to feel a little light-headed."

"Yeah. Feels like I'm scuba diving with the wrong mixture."

"Take a second. We have time," Robert said as he checks his watch. 7:07 p.m. "Actually, I take that back."

"Is that Mickey Mouse?" Vittoria asked, referring to Roberts watch. "Yeah. It's a long story," Robert answered and kept looking through the bookshelves. "It was confiscated from the Netherlands by the Vatican just after Galileo died. I've been petitioning to see it for about 10 years ever since I realised what was in it."

"What makes you so sure the segno's there?" Vittoria wanted to know.

"The number 503. I kept seeing it over and over again in Illuminati letters scribbled in the margins sometimes just signed 503. It's a numeric clue. But to what? Five? Well, that's a meaningful number to the Illuminati. There's the pentagram, Pythagoras, dozens of other examples in science. But what about three? Didn't make sense until I thought, what if it's Roman numerals?"

"D-I-I-I?"

"D-three. Galileo's third text. Dialogo. Discorso. Diagramma." His eyes lit up as he pulled out a folio bin on one of the top shelves. After having put on white cotton gloves, Robert set the folio bin onto the desk in front of him. He gently opened the bin, revealing the slender volume of Galileo's third text. "Just a few days with this and I could have actually finished my book and sold dozens of copies at the Harvard bookstore. Il Diagramma Veritatis."

"Diagram of Truth… I know about Dialogo and Discorsi. Galileo laid out his theories about the Earth revolving around the sun."

"Yeah, and said the Earth was not the centre of some universe with heaven above, hell below, as the Church had said it was."

"So they forced him to recant in the second book. But what was this one?"

"This is how he got the word out. This is the truth, not what the Vatican forced him to write. Smuggled out of Rome, printed in Holland on sedge papyrus. That way any scientist caught with a copy could just throw it in water and Galileo's heresy would dissolve, disappear. And between that and Vatican burnings it's possible that this is the only copy that remains. And if I'm correct the segno is hidden on page number…"

"Five… Do you need help with Latin?" Vittoria offered and moved beside him as he nodded. "Movement of the planets, elliptical orbits, heliocentricity. Sorry, I don't think there's anything that could be interpreted as a…," she said as she turned the page.

"Wait, wait, wait," Robert interposed. "Do that again."

Vittoria turned the page back and forth as Robert noticed something in the deep crevice of the margin as the page moved. He grabbed a magnifying glass to get a better look. "It's a watermark. And there's a line of text. It's in English."

"English? Why English?"

"English wasn't used in the Vatican. It was too polluted. It was free-thinking. It was a language of radicals like Shakespeare and Chaucer. Here's another one. The path of light is laid, the sacred test…"

"Will you write this down as I dictate?"

"Sorry, professor, no time."

Before Langdon could do anything to stop her, Vittoria ripped the page from the text and shoved it into her pocket. Robert's jaw dropped. "Yeah, yeah, what the hell. Yeah."