"Hurry," Vittoria said, still holding the folio in her hand and striding at a half-jog acrossVia Borgia in the direction of Olivetti's office.

Langdon and Vittoria exploded onto the courtyard outside the Secret Archives. The fresh air felt like a drug as it flowed into Langdon's lungs. The purple spots in his vision quickly faded. The guilt, however, did not. He had just been accomplice to stealing a priceless relic from the world's most private vault. The camerlegno had said, I am giving you my trust.

"If any water gets on that papyrus --"

Langdon accelerated to keep up. Beyond feeling like a criminal, he was still dazed over the document's spellbinding implications. John Milton was an Illuminatus. He composed the poem for Galileo to publish in Folio 5…far from the eyes of the Vatican.

"Calm down. When we decipher this thing, we can return their sacred Folio 5."

As they left the courtyard, Vittoria held out the folio for Langdon. "You think you can decipher this thing? Or did we just kill all those brain cells for kicks?"

Langdon took the document carefully in his hands. Without hesitation he slipped it into one of the breast pockets of his tweed jacket, out of the sunlight and dangers of moisture. "I deciphered it already."

Vittoria stopped short. "Youwhat?"

Vittoria hustled to catch up. "You read itonce! I thought it was supposed to be hard!"

Langdon knew she was right, and yet he had deciphered thesegno in a single reading. A perfect stanza of iambic pentameter, and the first altar of science had revealed itself in pristine clarity. Admittedly, the ease with which he had accomplished the task left him with a nagging disquietude. He was a child of the Puritan work ethic. He could still hear his father speaking the old New England aphorism: If it wasn't painfully difficult, you did it wrong. Langdon hoped the saying was false. "I deciphered it," he said, moving faster now. "I know where the first killing is going to happen. We need to warn Olivetti."

Langdon kept moving.

Vittoria closed in on him. "How could you already know? Let me see that thing again." With the sleight of a boxer, she slipped a lissome hand into his pocket and pulled out the folio again.

"Careful!" Langdon said. "You can't --"

For a moment, hearing the verse aloud, Langdon felt transported in time… as though he were one of Galileo's contemporaries, listening to the poem for the first time… knowing it was a test, a map, a clue unveiling the four altars of science… the four markers that blazed a secret path across Rome. The verse flowed from Vittoria's lips like a song.

"Cross Rome the mystic elements unfold.

Vittoria ignored him. Folio in hand, she floated beside him, holding the document up to the evening light, examining the margins. As she began reading aloud, Langdon moved to retrieve the folio but instead found himself bewitched by Vittoria's accented alto speaking the syllables in perfect rhythm with her gait.

From Santi's earthly tomb with demon's hole,

The path of light is laid, the sacred test,

Let angels guide you on your lofty quest.

Vittoria read it twice and then fell silent, as if letting the ancient words resonate on their own.

From Santi's earthly tomb, Langdon repeated in his mind. The poem was crystal clear about that. The Path of Illumination began at Santi's tomb. From there, across Rome, the markers blazed the trail.

"Cross Rome the mystic elements unfold.

From Santi's earthly tomb with demon's hole,

Langdon smiled. "I told you it wasn't that tough."

Mystic elements. Also clear. Earth, Air, Fire, Water. Elements of science, the four Illuminati markers disguised as religious sculpture.

"The first marker," Vittoria said, "sounds like it's at Santi's tomb."

"So who is Santi?" she asked, sounding suddenly excited. "And where's his tomb?"

Langdon chuckled to himself. He was amazed how few people knewSanti, the last name of one of the most famous Renaissance artists ever to live. His first name was world renowned… the child prodigy who at the age of twenty-five was already doing commissions for Pope Julius II, and when he died at only thirty-eight, left behind the greatest collection of frescoes the world had ever seen. Santi was a behemoth in the art world, and being known solely by one's first name was a level of fame achieved only by an elite few… people like Napoleon, Galileo, and Jesus… and, of course, the demigods Langdon now heard blaring from Harvard dormitories -- Sting, Madonna, Jewel, and the artist formerly known as Prince, who had changed his name to the symbol, causing Langdon to dub him "The Tau Cross With Intersecting Hermaphroditic Ankh."

"Santi," Langdon said, "is the last name of the great Renaissance master, Raphael."

Vittoria looked surprised. "Raphael? As inthe Raphael?"

"So the path starts at Raphael's tomb?"

Vittoria slipped the folio carefully back in Langdon's pocket. "So where is he buried?"

"It actually makes perfect sense," Langdon said as they rushed on. "The Illuminati often considered great artists and sculptors honorary brothers in enlightenment. The Illuminati could have chosen Raphael's tomb as a kind of tribute." Langdon also knew that Raphael, like many other religious artists, was a suspected closet atheist.

"The one and only." Langdon pushed on toward the Office of the Swiss Guard.

Vittoria looked skeptical."The Pantheon?"

Langdon took a deep breath. "Believe it or not, Raphael's buried in the Pantheon."

"TheRaphael atthe Pantheon." Langdon had to admit, the Pantheon was not what he had expected for the placement of the first marker. He would have guessed the first altar of science to be at some quiet, out of the way church, something subtle. Even in the 1600s, the Pantheon, with its tremendous, holed dome, was one of the best known sites in Rome.

Vittoria shook her head. "But do you really think the first cardinal could be killed at the Pantheon? That's got to be one of the busiest tourist spots in Rome."

"Is the Pantheon even achurch?" Vittoria asked.

"The poem said Santi"searthly tomb. Does that mean anything to you?"

"Is the Pantheon far?"

Langdon hastened diagonally across the Courtyard of the Sentinel. "Earthly? Actually, there's probably no more earthly place in Rome than the Pantheon. It got its name from the original religion practiced there -- Pantheism -- the worship of all gods, specifically the pagan gods of Mother Earth."

"And you"recertain Raphael is buried inside the Pantheon?"

"As impossible as kidnapping four cardinals from Vatican City? The poem is precise."

"Oldest Catholic church in Rome."

Vittoria nodded, still looking troubled. "What time is it?"

"But how does this guy expect to kill someone at the Pantheon and get away unnoticed? It would be impossible."

"A mile maybe. We've got time."

Langdon checked. "Seven-thirty."

Langdon shrugged. "The Illuminati said they wanted the whole world watching. Killing a cardinal at the Pantheon would certainly open some eyes."

"I've seen his tomb many times."

"Okay," Vittoria said, sounding more convinced. "And demon's hole? From Santi's earthly tomb with demon's hole?"

"But it's achurch," Vittoria said, moving effortlessly beside him. "Why would they call the opening ademon's hole?"

As a student of architecture, Langdon had been amazed to learn that the dimensions of the Pantheon's main chamber were a tribute to Gaea -- the goddess of the Earth. The proportions were so exact that a giant spherical globe could fit perfectly inside the building with less than a millimeter to spare.

Langdon had actually been wondering that himself. He had never heard the term "demon's hole," but he did recall a famous sixth-century critique of the Pantheon whose words seemed oddly appropriate now. The Venerable Bede had once written that the hole in the Pantheon's roof had been bored by demons trying to escape the building when it was consecrated by Boniface IV.

Langdon was not quite as sure about this."Demon's hole must mean theoculus," he said, making a logical guess. "The famous circular opening in the Pantheon's roof."

Langdon agreed. "Okay, then maybe using "Santi" was to make the clue more obscure, so only very enlightened men would recognize the reference to Raphael."

"Surprisingly not. Single name recognition was a status symbol. Raphael shunned his last name much like pop stars do today. Take Madonna, for example. She never uses her surname, Ciccone."

"You ask a lot of questions."

"Sounds like a stretch."

Langdon regretted the example. It was amazing the kind of garbage a mind picked up living with 10,000 adolescents.

As he and Vittoria passed the final gate toward the Office of the Swiss Guard, their progress was halted without warning.

"Two possible reasons. One, the wordRaphael has too many syllables. It would have destroyed the poem's iambic pentameter."

Vittoria looked amused. "You know Madonna's last name?"

Vittoria didn't appear to buy this either. "I'm sure Raphael's last name was very well known when he was alive."

"My dad used to say that."

"And why," Vittoria added as they entered a smaller courtyard, "why would the Illuminati use the name Santi if he was really known asRaphael?"

"We have good news," Langdon said.

"Para!"a voice bellowed behind them.

The guard looked bewildered."Ma, signore, è una donna --"

"Non sportarti!"the guard snapped, cocking the weapon.

Olivetti's eyes narrowed. "It better bedamn good."

Langdon and Vittoria wheeled to find themselves looking into the barrel of a rifle.

"Attento!"Vittoria exclaimed, jumping back. "Watch it with --"

"Signore, non posso --"

Looking bewildered, the guard hurried into the security center. Olivetti marched toward Langdon, rigid and steaming. "Our most secret archives? I'll want an explanation."

"Soldato!"a voice commanded from across the courtyard. Olivetti was emerging from the security center. "Let them go!"

"Inside!" he yelled at the guard.

"Now! You have new orders. Captain Rocher will be briefing the corps in two minutes. We will be organizing a search."