rofessor Langdon?” Sato said. “You look like you’ve seen a ghost. Are you okay?”

Langdon hoisted his daybag higher onto his shoulder and laid his hand on top of it, as if somehow this might better hide the cube-shaped package he was carrying. He could feel his face had gone ashen. “I’m . . . just worried about Peter.”

Sato cocked her head, eyeing him askew.

Langdon felt a sudden wariness that Sato’s involvement tonight might relate to this small package that Solomon had entrusted to him. Peter had warned Langdon: Powerful people want to steal this. It would be dangerous in the wrong hands. Langdon couldn’t imagine why the CIA would want a little box containing a talisman . . . or even what the talisman could be. Ordo ab chao?

Sato stepped closer, her black eyes probing. “I sense you’ve had a revelation?”

Langdon felt himself sweating now. “No, not exactly.”

“What’s on your mind?”

“I just . . .” Langdon hesitated, having no idea what to say. He had no intention of revealing the existence of the package in his bag, and yet if Sato took him to the CIA, his bag most certainly would be searched on the way in. “Actually . . .” he fibbed, “I have another idea about the numbers on Peter’s hand.”

Sato’s expression revealed nothing. “Yes?” She glanced over at Anderson now, who was just arriving from greeting the forensics team that had finally arrived.

Langdon swallowed hard and crouched down beside the hand, wondering what he could possibly come up with to tell them. You’re a teacher, Robert—improvise! He took one last look at the seven tiny symbols, hoping for some sort of inspiration.

Nothing. Blank.

As Langdon’s eidetic memory skimmed through his mental encyclopedia of symbols, he could find only one possible point to make. It was something that had occurred to him initially, but had seemed unlikely. At the moment, however, he had to buy time to think.

“Well,” he began, “a symbologist’s first clue that he’s on the wrong track when deciphering symbols and codes is when he starts interpreting symbols using multiple symbolic languages. For example, when I told you this text was Roman and Arabic, that was a poor analysis because I used multiple symbolic systems. The same is true for Roman and runic.”

Sato crossed her arms and arched her eyebrows as if to say, “Go on.”

“In general, communications are made in one language, not multiple languages, and so a symbologist’s first job with any text is to find a single consistent symbolic system that applies to the entire text.”

“And you see a single system now?”

“Well, yes . . . and no.” Langdon’s experience with the rotational symmetry of ambigrams had taught him that symbols sometimes had meanings from multiple angles. In this case, he realized there was indeed a way to view all seven symbols in a single language. “If we manipulated the hand slightly, the language will become consistent.” Eerily, the manipulation Langdon was about to perform was one that seemed to have been suggested by Peter’s captor already when he spoke the ancient Hermetic adage. As above, so below.

Langdon felt a chill as he reached out and grasped the wooden base on which Peter’s hand was secured. Gently, he turned the base upside down so that Peter’s extended fingers were now pointing straight down. The symbols on the palm instantly transformed themselves.

“From this angle,” Langdon said, “X-I-I-I becomes a valid Roman numeral—thirteen. Moreover, the rest of the characters can be interpreted using the Roman alphabet—SBB.” Langdon assumed the analysis would elicit blank shrugs, but Anderson’s expression immediately changed.

“SBB?” the chief demanded.

Sato turned to Anderson. “If I’m not mistaken, that sounds like a familiar numbering system here in the Capitol Building.”

Anderson looked pale. “It is.”

Sato gave a grim smile and nodded to Anderson. “Chief, follow me, please. I’d like a word in private.”

As Director Sato led Chief Anderson out of earshot, Langdon stood alone in bewilderment. What the hell is going on here? And what is SBB XIII?

Chief Anderson wondered how this night could possibly get any stranger. The hand says SBB13? He was amazed any outsider had even heard of SBB . . . much less SBB13. Peter Solomon’s index finger, it seemed, was not directing them upward as it had appeared . . . but rather was pointing in quite the opposite direction.

Director Sato led Anderson over to a quiet area near the bronze statue of Thomas Jefferson. “Chief,” she said, “I trust you know exactly where SBB Thirteen is located?”

“Of course.”

“Do you know what’s inside?”

“No, not without looking. I don’t think it’s been used in decades.”

“Well, you’re going to open it up.”

Anderson did not appreciate being told what he would do in his own building. “Ma’am, that may be problematic. I’ll have to check the assignment roster first. As you know, most of the lower levels are private offices or storage, and security protocol regarding private—”

“You will unlock SBB Thirteen for me,” Sato said, “or I will call OS and send in a team with a battering ram.”

Anderson stared at her a long moment and then pulled out his radio, raising it to his lips. “This is Anderson. I need someone to unlock the SBB. Have someone meet me there in five minutes.”

The voice that replied sounded confused. “Chief, confirming you said SBB?”

“Correct. SBB. Send someone immediately. And I’ll need a flashlight.” He stowed his radio. Anderson’s heart was pounding as Sato stepped closer, lowering her voice even further.

“Chief, time is short,” she whispered, “and I want you to get us down to SBB Thirteen as quickly as possible.”

“Yes, ma’am.”

“I also need something else from you.”

In addition to breaking and entering? Anderson was in no position to protest, and yet it had not gone unnoticed by him that Sato had arrived within minutes of Peter’s hand appearing in the Rotunda, and that she now was using the situation to demand access to private sections of the U.S. Capitol. She seemed so far ahead of the curve tonight that she was practically defining it.

Sato motioned across the room toward the professor. “The duffel bag on Langdon’s shoulder.”

Anderson glanced over. “What about it?”

“I assume your staff X-rayed that bag when Langdon entered the building?”

“Of course. All bags are scanned.”

“I want to see that X-ray. I want to know what’s in his bag.”

Anderson looked over at the bag Langdon had been carrying all evening. “But . . . wouldn’t it be easier just to ask him?”

“What part of my request was unclear?”

Anderson pulled out his radio again and called in her request. Sato gave Anderson her BlackBerry address and requested that his team e-mail her a digital copy of the X-ray as soon as they had located it. Reluctantly Anderson complied.

Forensics was now collecting the severed hand for the Capitol Police, but Sato ordered them to deliver it directly to her team at Langley. Anderson was too tired to protest. He had just been run over by a tiny Japanese steamroller.

“And I want that ring,” Sato called over to Forensics.

The chief technician seemed ready to question her but thought better of it. He removed the gold ring from Peter’s hand, placed it in a clear specimen bag, and gave it to Sato. She slipped it into her jacket pocket, and then turned to Langdon.

“We’re leaving, Professor. Bring your things.”

“Where are we going?” Langdon replied.

“Just follow Mr. Anderson.”

Yes, Anderson thought, and follow me closely. The SBB was a section of the Capitol that few ever visited. To reach it, they would pass through a sprawling labyrinth of tiny chambers and tight passages buried beneath the crypt. Abraham Lincoln’s youngest son, Tad, had once gotten lost down there and almost perished. Anderson was starting to suspect that if Sato had her way, Robert Langdon might suffer a similar fate.