RAPPED IN wool blankets, Langdon stood on wobbly legs and stared down at the open tank of liquid. His body had returned to him, although he wished it had not. His throat and lungs burned. This world felt hard and cruel.

Sato had just explained the sensory-deprivation tank … adding that if she had not pulled him out, he would have died of starvation, or worse. Langdon had little doubt that Peter had endured a similar experience. Peter is in the in-between, the tattooed man had told him earlier tonight. He is in purgatory … Hamistagan. If Peter had endured more than one of those birthing processes, Langdon would not have been surprised if Peter had told his captor anything he had wanted to know.

Sato motioned for Langdon to follow her, and he did, trudging slowly down a narrow hall, deeper into this bizarre lair that he was now seeing for the first time. They entered a square room with a stone table and eerie-colored lighting. Katherine was here, and Langdon heaved a sigh of relief. Even so, the scene was worrisome.

Katherine was lying on her back on a stone table. Blood-soaked towels lay on the floor. A CIA agent was holding an IV bag above her, the tube connected to her arm.

She was sobbing quietly.

“Katherine?” Langdon croaked, barely able to speak.

She turned her head, looking disorientated and confused. “Robert?!” Her eyes widened with disbelief and then joy. “But I … saw you drown!”

He moved toward the stone table.

Katherine pulled herself to a seated position, ignoring her IV tube and the medical objections of the agent. Langdon reached the table, and Katherine reached out, wrapping her arms around his blanket-clad body, holding him close. “Thank God,” she whispered, kissing his cheek. Then she kissed him again, squeezing him as though she didn’t believe he was real. “I don’t understand … how …”

Sato began saying something about sensory-deprivation tanks and oxygenated perfluorocarbons, but Katherine clearly wasn’t listening. She just held Langdon close.

“Robert,” she said, “Peter’s alive.” Her voice wavered as she recounted her horrifying reunion with Peter. She described his physical condition—the wheelchair, the strange knife, the allusions to some kind of “sacrifice,” and how she had been left bleeding as a human hourglass to persuade Peter to cooperate quickly.

Langdon could barely speak. “Do you … have any idea where … they went?!”

“He said he was taking Peter to the sacred mountain.”

Langdon pulled away and stared at her.

Katherine had tears in her eyes. “He said he had deciphered the grid on the bottom of the pyramid, and that the pyramid told him to go to the sacred mountain.”

“Professor,” Sato pressed, “does that mean anything to you?”

Langdon shook his head. “Not at all.” Still, he felt a surge of hope. “But if he got the information off the bottom of the pyramid, we can get it, too.” I told him how to solve it.

Sato shook her head. “The pyramid’s gone. We’ve looked. He took it with him.”

Langdon remained silent a moment, closing his eyes and trying to recall what he had seen on the base of the pyramid. The grid of symbols had been one of the last images he had seen before drowning, and trauma had a way of burning memories deeper into the mind. He could recall some of the grid, definitely not all of it, but maybe enough?

He turned to Sato and said hurriedly, “I may be able to remember enough, but I need you to look up something on the Internet.”

She pulled out her BlackBerry.

“Run a search for ‘The Order Eight Franklin Square.’ ”

Sato gave him a startled look but began typing without questions.

Langdon’s vision was still blurry, and he was only now starting to process his strange surroundings. He realized that the stone table on which they were leaning was covered with old bloodstains, and the wall to his right was entirely plastered with pages of text, photos, drawings, maps, and a giant web of strings interconnecting them.

My God.

Langdon moved toward the strange collage, still clutching the blankets around his body. Tacked on the wall was an utterly bizarre collection of information—pages from ancient texts ranging from black magic to Christian Scripture, drawings of symbols and sigils, pages of conspiracy-theory Web sites, and satellite photos of Washington, D.C., scrawled with notes and question marks. One of the sheets was a long list of words in many languages. He recognized some of them as sacred Masonic words, others as ancient magic words, and others from ceremonial incantations.

Is that what he’s looking for?

A word?

Is it that simple?

Langdon’s long-standing skepticism about the Masonic Pyramid was based largely on what it allegedly revealed—the location of the Ancient Mysteries. This discovery would have to involve an enormous vault filled with thousands upon thousands of volumes that had somehow survived the long-lost ancient libraries in which they had once been stored. It all seemed impossible. A vault that big? Beneath D.C.? Now, however, his recollection of Peter’s lecture at Phillips Exeter, combined with these lists of magic words, had opened another startling possibility.

Langdon most definitely did not believe in the power of magic words … and yet it seemed pretty clear that the tattooed man did. His pulse quickened as he again scanned the scrawled notes, the maps, the texts, the printouts, and all the interconnected strings and sticky notes.

Sure enough, there was one recurring theme.

My God, he’s looking for the verbum significatium … the Lost Word. Langdon let the thought take shape, recalling fragments of Peter’s lecture. The Lost Word is what he’s looking for! That’s what he believes is buried here in Washington.

Sato arrived beside him. “Is this what you asked for?” She handed him her Black-Berry.

Langdon looked at the eight-by-eight grid of numbers on the screen. “Exactly.” He grabbed a piece of scrap paper. “I’ll need a pen.”

Sato handed him one from her pocket. “Please hurry.”

Inside the basement office of the Directorate of Science and Technology, Nola Kaye was once again studying the redacted document brought to her by sys-sec Rick Parrish. What the hell is the CIA director doing with a file about ancient pyramids and secret underground locations?

She grabbed the phone and dialed.

Sato answered instantly, sounding tense. “Nola, I was just about to call you.”

“I have new information,” Nola said. “I’m not sure how this fits, but I’ve discovered there’s a redacted—”

“Forget it, whatever it is,” Sato interrupted. “We’re out of time. We failed to apprehend the target, and I have every reason to believe he’s about to carry out his threat.”

Nola felt a chill.

“The good news is we know exactly where he’s going.” Sato took a deep breath. “The bad news is that he’s carrying a laptop with him.”

ESS THAN ten miles away, Mal’akh tucked the blanket around Peter Solomon and wheeled him across a moonlit parking lot into the shadow of an enormous building.

The structure had exactly thirty-three outer columns … each precisely thirty-three feet tall. The mountainous structure was deserted at this hour, and nobody would ever see them back here. Not that it mattered. From a distance, no one would think twice about a tall, kindly-looking man in a long black coat taking a bald invalid for an evening stroll.

When they reached the rear entrance, Mal’akh wheeled Peter up close to the security keypad. Peter stared at it defiantly, clearly having no intention of entering the code.

Mal’akh laughed. “You think you’re here to let me in? Have you forgotten so soon that I am one of your brethren?” He reached out and typed the access code that he had been given after his initiation to the thirty-third degree.

The heavy door clicked open.

Peter groaned and began struggling in the wheelchair.

“Peter, Peter,” Mal’akh cooed. “Picture Katherine. Be cooperative, and she will live. You can save her. I give you my word.”

Mal’akh wheeled his captive inside and relocked the door behind them, his heart racing now with anticipation. He pushed Peter through some hallways to an elevator and pressed the call button. The doors opened, and Mal’akh backed in, pulling the wheelchair along with him. Then, making sure Peter could see what he was doing, he reached out and pressed the uppermost button.

A look of deepening dread crossed Peter’s tortured face.

“Shh …” Mal’akh whispered, gently stroking Peter’s shaved head as the elevator doors closed. “As you well know … the secret is how to die.”

I can’t remember all the symbols!

Langdon closed his eyes, doing his best to recall the precise locations of the symbols on the bottom of the stone pyramid, but even his eidetic memory did not have that degree of recall. He wrote down the few symbols he could remember, placing each one in the location indicated by Franklin’s magic square.

So far, however, he saw nothing that made any sense.

“Look!” Katherine urged. “You must be on the right track. The first row is all Greek letters—the same kinds of symbols are being arranged together!”

Langdon had noticed this, too, but he could not think of any Greek word that fit that configuration of letters and spaces. I need the first letter. He glanced again at the magic square, trying to recall the letter that had been in the number one spot near the lower left corner. Think! He closed his eyes, trying to picture the base of the pyramid. The bottom row … next to the left-hand corner … what letter was there?

For an instant, Langdon was back in the tank, racked with terror, staring up through the Plexiglas at the bottom of the pyramid.

Now, suddenly, he saw it. He opened his eyes, breathing heavily. “The first letter is H!”

Langdon turned back to the grid and wrote in the first letter. The word was still incomplete, but he had seen enough. Suddenly he realized what the word might be.

Pulse pounding, Langdon typed a new search into the BlackBerry. He entered the English equivalent of this well-known Greek word. The first hit that appeared was an encyclopedia entry. He read it and knew it had to be right.

“That’s it!” Langdon exclaimed, incredulous. “That’s where they went!”

Sato had been reading over his shoulder and looked lost. “To a mythical mountain in Scotland?!”

Langdon shook his head. “No, to a building in Washington whose code name is Heredom.”