obert Langdon studied the stone pyramid. This isn’t possible.

“An ancient encoded language,” Sato said without looking up. “Tell me, does this qualify?”

On the newly exposed face of the pyramid, a series of sixteen characters was precisely engraved into the smooth stone.

Beside Langdon, Anderson’s mouth now gaped open, mirroring Langdon’s own shock. The security chief looked like he had just seen some kind of alien keypad.

“Professor?” Sato said. “I assume you can read this?”

Langdon turned. “Why would you assume that?”

“Because you were brought here, Professor. You were chosen. This inscription appears to be a code of some sort, and considering your reputation, it seems obvious to me that you were brought here to decipher it.”

Langdon had to admit that after his experiences in Rome and Paris, he’d received a steady flow of requests asking for his help deciphering some of history’s great unsolved codes—the Phaistos Disk, the Dorabella Cipher, the mysterious Voynich Manuscript.

Sato ran her finger over the inscription. “Can you tell me the meaning of these icons?”

They’re not icons, Langdon thought. They’re symbols. The language was one he had recognized immediately—an encrypted cipher language from the seventeenth century. Langdon knew very well how to break it. “Ma’am,” he said, feeling hesitant, “this pyramid is Peter’s private property.”

“Private or not, if this code is indeed the reason you were brought to Washington, I am not giving you a choice in the matter. I want to know what it says.”

Sato’s BlackBerry pinged loudly, and she yanked the device from her pocket, studying the incoming message for several moments. Langdon was amazed that the Capitol Building’s internal wireless network provided service this far down.

Sato grunted and raised her eyebrows, giving Langdon an odd look.

“Chief Anderson?” she said, turning to him. “A word in private, if I may?” The director motioned for Anderson to join her, and they disappeared into the pitch-black hallway, leaving Langdon alone in the flickering candlelight of Peter’s Chamber of Reflection.

Chief Anderson wondered when this night would end. A severed hand in my Rotunda? A death shrine in my basement? Bizarre engravings on a stone pyramid? Somehow, the Redskins game no longer felt significant.

As he followed Sato into the darkness of the hall, Anderson flicked on his flashlight. The beam was weak but better than nothing. Sato led him down the hall a few yards, out of sight of Langdon.

“Have a look at this,” she whispered, handing Anderson her BlackBerry.

Anderson took the device and squinted at the illuminated screen. It displayed a black-and-white image—the X-ray of Langdon’s bag that Anderson had requested be sent to Sato. As in all X-rays, the objects of greatest density appeared in the brightest white. In Langdon’s bag, a lone item outshone everything else. Obviously extremely dense, the object glowed like a dazzling jewel in a murky jumble of other items. Its shape was unmistakable.

He’s been carrying that all night? Anderson looked over at Sato in surprise. “Why didn’t Langdon mention this?”

“Damned good question,” Sato whispered.

“The shape . . . it can’t be coincidence.”

“No,” Sato said, her tone angry now. “I would say not.”

A faint rustle in the corridor drew Anderson’s attention. Startled, he pointed his flashlight down the black passageway. The dying beam revealed only a deserted corridor, lined with open doors.

“Hello?” Anderson said. “Is somebody there?”

Silence.

Sato gave him an odd look, apparently having heard nothing.

Anderson listened a moment longer and then shook it off. I’ve got to get out of here.

Alone in the candlelit chamber, Langdon ran his fingers over the sharply carved edges of the pyramid’s engraving. He was curious to know what the message said, and yet he was not about to intrude on Peter Solomon’s privacy any more than they already had. And why would this lunatic care about this small pyramid anyway?

“We have a problem, Professor,” Sato’s voice declared loudly behind him. “I’ve just received a new piece of information, and I’ve had enough of your lies.”

Langdon turned to see the OS director marching in, BlackBerry in hand and fire in her eyes. Taken aback, Langdon looked to Anderson for help, but the chief was now standing guard at the door, his expression unsympathetic. Sato arrived in front of Langdon and thrust her BlackBerry in his face.

Bewildered, Langdon looked at the screen, which displayed an inverted black-and-white photograph, like a ghostly film negative. The photo looked like a jumble of objects, and one of them shone very brightly. Though askew and off center, the brightest object was clearly a little, pointed pyramid.

A tiny pyramid? Langdon looked at Sato. “What is this?”

The question seemed only to incense Sato further. “You’re pretending you don’t know?”

Langdon’s temper flared. “I’m not pretending anything! I’ve never seen this before in my life!”

“Bullshit!” Sato snapped, her voice cutting through the musty air. “You’ve been carrying it in your bag all night!”

“I—” Langdon stalled midsentence. His eyes moved slowly down to the daybag on his shoulder. Then he raised them again to the BlackBerry. My God . . . the package. He looked more closely at the image. Now he saw it. A ghostly cube, enclosing the pyramid. Stunned, Langdon realized he was looking at an X-ray of his bag . . . and also of Peter’s mysterious cube-shaped package. The cube was, in fact, a hollow box . . . a small pyramid.

Langdon opened his mouth to speak, but his words failed him. He felt the breath go out of his lungs as a new revelation struck him.

Simple. Pure. Devastating.

My God. He looked back at the truncated stone pyramid on the desk. Its apex was flat—a small square area—a blank space symbolically awaiting its final piece . . . that piece which would transform it from an Unfinished Pyramid into a True Pyramid.

Langdon now realized the tiny pyramid he was carrying was not a pyramid at all. It’s a capstone. At that instant, he knew why he alone could unlock the mysteries of this pyramid.

I hold the final piece.

And it is indeed . . . a talisman.

When Peter had told Langdon the package contained a talisman, Langdon had laughed. Now he realized his friend was right. This tiny capstone was a talisman, but not the magic kind . . . the far older kind. Long before talisman had magical connotations, it had another meaning—“completion.” From the Greek telesma, meaning “complete,” a talisman was any object or idea that completed another and made it whole. The finishing element. A capstone, symbolically speaking, was the ultimate talisman, transforming the Unfinished Pyramid into a symbol of completed perfection.

Langdon now felt an eerie convergence that forced him to accept one very strange truth: with the exception of its size, the stone pyramid in Peter’s Chamber of Reflection seemed to be transforming itself, bit by bit, into something vaguely resembling the Masonic Pyramid of legend.

From the brightness with which the capstone shone on the X-ray, Langdon suspected it was made of metal . . . a very dense metal. Whether or not it was solid gold, he had no way of knowing, and he was not about to let his mind start playing tricks on him. This pyramid is too small. The code’s too easy to read. And . . . it’s a myth, for heaven’s sake!

Sato was watching him. “For a bright man, Professor, you’ve made some dumb choices tonight. Lying to an intelligence director? Intentionally obstructing a CIA investigation?”

“I can explain, if you’ll let me.”

“You will be explaining at CIA headquarters. As of this moment, I am detaining you.”

Langdon’s body went rigid. “You can’t possibly be serious.”

“Deadly serious. I made it very clear to you that the stakes tonight were high, and you chose not to cooperate. I strongly suggest you start thinking about explaining the inscription on this pyramid, because when we arrive at the CIA . . .” She raised her BlackBerry and took a close-up snapshot of the engraving on the stone pyramid. “My analysts will have had a head start.”

Langdon opened his mouth to protest, but Sato was already turning to Anderson at the door. “Chief,” she said, “put the stone pyramid in Langdon’s bag and carry it. I’ll handle taking Mr. Langdon into custody. Your weapon, if I may?”

Anderson was stone-faced as he advanced into the chamber, unsnapping his shoulder holster as he came. He gave his gun to Sato, who immediately aimed it at Langdon.

Langdon watched as if in a dream. This cannot be happening.

Anderson now came to Langdon and removed the daybag from his shoulder, carrying it over to the desk and setting it on the chair. He unzipped the bag, propped it open, and then hoisted the heavy stone pyramid off the desk and into the bag, along with Langdon’s notes and the tiny package.

Suddenly there was a rustle of movement in the hallway. A dark outline of a man materialized in the doorway, rushing into the chamber and approaching fast behind Anderson. The chief never saw him coming. In an instant, the stranger had lowered his shoulder and crashed into Anderson’s back. The chief launched forward, his head cracking into the edge of the stone niche. He fell hard, crumpling on the desk, sending bones and artifacts flying. The hourglass shattered on the floor. The candle toppled to the floor, still burning.

Sato reeled amid the chaos, raising the gun, but the intruder grabbed a femur and lashed out with it, striking her shoulder with the leg bone. Sato let out a cry of pain and fell back, dropping the weapon. The newcomer kicked the gun away and then wheeled toward Langdon. The man was tall and slender, an elegant African American whom Langdon had never seen before in his life.

“Grab the pyramid!” the man commanded. “Follow me!”