«A sun, a lantern, and a key,» Langdon said flatly.

Sato turned fully to Langdon now, her small eyes appraising him. «And how exactly would you know that?»

Langdon stared back. «The image of a human hand, marked in this way on the fingertips, is a very old icon. It’s known as ‘the Hand of the Mysteries.’ »

Anderson stood up abruptly. «This thing has a name?»

Langdon nodded. «It’s one of the most secretive icons of the ancient world.»

Sato cocked her head. «Then might I ask what the hell it’s doing in the middle of the U.S. Capitol?»

Langdon wished he would wake up from this nightmare. «Traditionally, ma’am, it was used as an invitation.»

«An invitation. . to what?» she demanded.

Langdon looked down at the symbols on his friend’s severed hand. «For centuries, the Hand of the Mysteries served as a mystical summons. Basically, it’s an invitation to receive secret knowledge — protected wisdom known only to an elite few.»

Sato folded her thin arms and stared up at him with jet-black eyes. «Well, Professor, for someone who claims to have no clue why he’s here. . you’re doing quite well so far.»

Katherine Solomon donned her white lab coat and began her usual arrival routine — her «rounds» as her brother called them.

Like a nervous parent checking on a sleeping baby, Katherine poked her head into the mechanical room. The hydrogen fuel cell was running smoothly, its backup tanks all safely nestled in their racks.

Katherine continued down the hall to the data-storage room. As always, the two redundant holographic backup units hummed safely within their temperature-controlled vault. All of my research, she thought, gazing in through the three-inch-thick shatterproof glass. Holographic data-storage devices, unlike their refrigerator-size ancestors, looked more like sleek stereo components, each perched atop a columnar pedestal.

Both of her lab’s holographic drives were synchronized and identical — serving as redundant backups to safeguard identical copies of her work. Most backup protocols advocated a secondary backup system off-site in case of earthquake, fire, or theft, but Katherine and her brother agreed that secrecy was paramount; once this data left the building to an off-site server, they could no longer be certain it would stay private.

Content that everything was running smoothly here, she headed back down the hallway. As she rounded the corner, however, she spotted something unexpected across the lab. What in the world? A muted glow was glinting off all the equipment. She hurried in to have a look, surprised to see light emanating from behind the Plexiglas wall of the control room.

He’s here. Katherine flew across the lab, arriving at the control-room door and heaving it open. «Peter!» she said, running in. The plump woman seated at the control room’s terminal jumped up. «Oh my God! Katherine! You scared me!»

Trish Dunne — the only other person on earth allowed back here — was Katherine’s metasystems analyst and seldom worked weekends. The twenty-six-year-old redhead was a genius data modeler and had signed a nondisclosure document worthy of the KGB. Tonight, she was apparently analyzing data on the control room’s plasma wall — a huge flat-screen display that looked like something out of nasa mission control.

«Sorry,» Trish said. «I didn’t know you were here yet. I was trying to finish up before you and your brother arrived.»

«Have you spoken to him? He’s late and he’s not answering his phone.»

Trish shook her head. «I bet he’s still trying to figure out how to use that new iPhone you gave him.»

Katherine appreciated Trish’s good humor, and Trish’s presence here had just given her an idea. «Actually, I’m glad you’re in tonight. You might be able to help me with something, if you don’t mind?»

«Whatever it is, I’m sure it beats football.»

Katherine took a deep breath, calming her mind. «I’m not sure how to explain this, but earlier today, I heard an unusual story. .»

Trish Dunne didn’t know what story Katherine Solomon had heard, but clearly it had her on edge. Her boss’s usually calm gray eyes looked anxious, and she had tucked her hair behind her ears three times since entering the room — a nervous «tell,» as Trish called it. Brilliant scientist. Lousy poker player.

«To me,» Katherine said, «this story sounds like fiction. . an old legend. And yet. .» She paused, tucking a wisp of hair behind her ears once again.

«And yet?»

Katherine sighed. «And yet I was told today by a trusted source that the legend is true.»

«Okay. .» Where is she going with this?

«I’m going to talk to my brother about it, but it occurs to me that maybe you can help me shed some light on it before I do. I’d love to know if this legend has ever been corroborated anywhere else in history.»

«In all of history?»

Katherine nodded. «Anywhere in the world, in any language, at any point in history.»

Strange request, Trish thought, but certainly feasible. Ten years ago, the task would have been impossible. Today, however, with the Internet, the World Wide Web, and the ongoing digitization of the great libraries and museums in the world, Katherine’s goal could be achieved by using a relatively simple search engine equipped with an army of translation modules and some well-chosen keywords.

«no problem,» trish said. many of the lab’s research books contained passages in ancient languages, and so trish was often asked to write specialized optical character recognition translation modules to generate english text from obscure languages. she had to be the only metasystems specialist on earth who had built ocr translation modules in old frisian, maek, and akkadian.

The modules would help, but the trick to building an effective search spider was all in choosing the right key words. Unique but not overly restrictive.

Katherine looked to be a step ahead of Trish and was already jotting down possible keywords on a slip of paper. Katherine had written down several when she paused, thought a moment, and then wrote several more. «Okay,» she finally said, handing Trish the slip of paper.

Trish perused the list of search strings, and her eyes grew wide. What kind of crazy legend is Katherine investigating? «You want me to search for all of these key phrases?» One of the words Trish didn’t even recognize. Is that even English? «Do you really think we’ll find all of these in one place? Verbatim?»

«I’d like to try.»

Trish would have said impossible, but the I-word was banned here. Katherine considered it a dangerous mind-set in a field that often transformed preconceived falsehoods into confirmed truths. Trish Dunne seriously doubted this key-phrase search would fall into that category.

«How long for results?» Katherine asked.

«A few minutes to write the spider and launch it. After that, maybe fifteen for the spider to exhaust itself.»

«So fast?» Katherine looked encouraged.

Trish nodded. Traditional search engines often required a full day to crawl across the entire online universe, find new documents, digest their content, and add it to their searchable database. But this was not the kind of search spider Trish would write.

«I’ll write a program called a delegator, » Trish explained. «It’s not entirely kosher, but it’s fast. Essentially, it’s a program that orders other people’s search engines to do our work. Most databases have a search function built in — libraries, museums, universities, governments. So I write a spider that finds their search engines, inputs your keywords, and asks them to search. This way, we harness the power of thousands of engines, working in unison.»