"You're sureDiagramma is in here?" Vittoria asked.

The internal organization of Archival Vault 10 was not as intuitive as Langdon had hoped, and theDiagramma manuscript did not appear to be located with other similar Galilean publications. Without access to the computerized Biblion and a reference locator, Langdon and Vittoria were stuck.

"Positive. It's a confirmed listing in both theUficcio della Propaganda delle Fede --"

"Fine. As long as you're sure." She headed left, while he went right.

Langdon began his manual search. He needed every bit of self-restraint not to stop and read every treasure he passed. The collection was staggering. The Assayer…The Starry Messenger…The Sunspot Letters…Letter to the Grand Duchess Christina…Apologia pro Galileo… On and on.

It was Vittoria who finally struck gold near the back of the vault. Her throaty voice called out,"Diagramma della Verità!"

Vittoria pointed, and Langdon immediately realized why they had not found it earlier. The manuscript was in a folio bin, not on the shelves. Folio bins were a common means of storing unbound pages. The label on the front of the container left no doubt about the contents.

Langdon dashed through the crimson haze to join her. "Where?"

Langdon dropped to his knees, his heart pounding."Diagramma." He gave her a grin. "Nice work. Help me pull out this bin."

DIAGRAMMA DELLA VERITA

Galileo Galilei, 1639

Vittoria knelt beside him, and they heaved. The metal tray on which the bin was sitting rolled toward them on castors, revealing the top of the container.

"No lock?" Vittoria said, sounding surprised at the simple latch.

"Never. Documents sometimes need to be evacuated quickly. Floods and fires."

Langdon didn't need any encouragement. With his academic life's dream right in front of him and the thinning air in the chamber, he was in no mood to dawdle. He unsnapped the latch and lifted the lid. Inside, flat on the floor of the bin, lay a black, duck-cloth pouch. The cloth's breathability was critical to the preservation of its contents. Reaching in with both hands and keeping the pouch horizontal, Langdon lifted it out of the bin.

"I expected a treasure chest," Vittoria said. "Looks more like a pillowcase."

"So open it."

"Follow me," he said. Holding the bag before him like a sacred offering, Langdon walked to the center of the vault where he found the customary glass-topped archival exam table. Although the central location was intended to minimize in-vault travel of documents, researchers appreciated the privacy the surrounding stacks afforded. Career-making discoveries were uncovered in the top vaults of the world, and most academics did not like rivals peering through the glass as they worked.

"Relax," Vittoria said. "It's paper, not plutonium."

Langdon lay the pouch on the table and unbuttoned the opening. Vittoria stood by. Rummaging through a tray of archivist tools, Langdon found the felt-pad pincers archivists calledfinger cymbals oversized tweezers with flattened disks on each arm. As his excitement mounted, Langdon feared at any moment he might awake back in Cambridge with a pile of test papers to grade. Inhaling deeply, he opened the bag. Fingers trembling in their cotton gloves, he reached in with his tongs.

Langdon slid the tongs around the stack of documents inside and was careful to apply even pressure. Then, rather than pulling out the documents, he held them in place while he slid off the bag -- an archivist's procedure for minimizing torque on the artifact. Not until the bag was removed and Langdon had turned on the exam darklight beneath the table did he begin breathing again.

Vittoria looked like a specter now, lit from below by the lamp beneath the glass. "Small sheets," she said, her voice reverent.

In that instant, Langdon forgot the cramped quarters, forgot his exhaustion, forgot the horrifying situation that had brought him here. He simply stared in wonder. Close encounters with history always left Langdon numbed with reverence… like seeing the brushstrokes on the Mona Lisa.

Langdon nodded. The stack of folios before them looked like loose pages from a small paperback novel. Langdon could see that the top sheet was an ornate pen and ink cover sheet with the title, the date, and Galileo's name in his own hand.

The muted, yellow papyrus left no doubt in Langdon's mind as to its age and authenticity, but excluding the inevitable fading, the document was in superb condition. Slight bleaching of the pigment. Minor sundering and cohesion of the papyrus. But all in all…in damn fine condition. He studied the ornate hand etching of the cover, his vision blurring in the lack of humidity. Vittoria was silent.

"Hand me a spatula, please." Langdon motioned beside Vittoria to a tray filled with stainless-steel archival tools. She handed it to him. Langdon took the tool in his hand. It was a good one. He ran his fingers across the face to remove any static charge and then, ever so carefully, slid the blade beneath the cover. Then, lifting the spatula, he turned over the cover sheet.

Langdon frowned. On any other day, he would have been fascinated to read it; incredibly NASA's current model of planetary orbits, observed through high-powered telescopes, was supposedly almost identical to Galileo's original predictions.

"Forget it," Langdon said. "We're looking for math. The pure language." He used the spatula tool to flip the next page. Another essay. No math or diagrams. Langdon's hands began to sweat inside his gloves.

"Heliocentricity," Vittoria said, translating the heading on folio one. She scanned the text. "Looks like Galileo renouncing the geocentric model once and for all. Ancient Italian, though, so no promises on the translation."

"Movement of the Planets," Vittoria said, translating the title.

The first page was written in longhand, the tiny, stylized calligraphy almost impossible to read. Langdon immediately noticed that there were no diagrams or numbers on the page. It was an essay.

"No math," Vittoria said. "He's talking about retrograde motions and elliptical orbits or something."

Elliptical orbits. Langdon recalled that much of Galileo's legal trouble had begun when he described planetary motion aselliptical. The Vatican exalted the perfection of thecircle and insisted heavenly motion must be only circular. Galileo's Illuminati, however, saw perfection in the ellipse as well, revering the mathematical duality of its twin foci. The Illuminati's ellipse was prominent even today in modern Masonic tracing boards and footing inlays.

Langdon flipped.

"Lunar phases and tidal motion," she said. "No numbers. No diagrams."

"Next," Vittoria said.

Langdon felt the air in his lungs beginning to thin. His hopes were thinning too. The pile was waning.

Langdon flipped again. Nothing. He kept flipping through a dozen or so pages. Nothing. Nothing. Nothing.

"I thought this guy was a mathematician," Vittoria said. "This is all text."

"Nothing here," Vittoria said. "No math. A few dates, a few standard figures, but nothing that looks like it could be a clue."

Langdon flipped over the last folio and sighed. It, too, was an essay.

"Lingua pura. What else would it be?"

"Merda, as we say in Rome."

"Except there are no diagrams or pictures in the book."

"I agree."

"Okay," she agreed, "DIII makes perfect sense. But maybe the clue isn't mathematical?"

"Time's something we don't have. We'll have to split the work." Langdon flipped the stack back over to the beginning. "I know enough Italian to spot numbers." Using his spatula, he cut the stack like a deck of cards and lay the first half-dozen pages in front of Vittoria. "It's in here somewhere. I'm sure."

Langdon nodded.

Langdon turned and stared at her.

"Art?"

"Maybe you were wrong about DIII?"

Langdon refused to accept defeat so quickly. "The numbers must be written longhand. The math must be in words rather than equations."

"It'll take some time to read all the pages."

"All I know is thatlingua pura refers to something other than Italian. Math just seems logical."

Shit is right, Langdon thought. His reflection in the glass seemed mocking, like the image staring back at him this morning from his bay window. An aging ghost. "There"sgot to be something," he said, the hoarse desperation in his voice surprising him. "Thesegno is here somewhere. I know it!"

"Short book," Vittoria said, frowning.

Vittoria reached down and flipped her first page by hand.

"I'm wearing gloves," she grumbled. "How much damage could I cause?"

"Just use it."

"Spatula!" Langdon said, grabbing her an extra tool from the tray. "Use the spatula."

Vittoria picked up the spatula. "You feeling what I'm feeling?"

"No. Short of breath."

Langdon was definitely starting to feel it too. The air was thinning faster than he had imagined. He knew they had to hurry. Archival conundrums were nothing new for him, but usually he had more than a few minutes to work them out. Without another word, Langdon bowed his head and began translating the first page in his stack.

"Tense?"

Show yourself, damn it! Show yourself!