Fighting a wave of nausea, Langdon let his eyes fall to the victim's chest. Although Langdon had stared at the symmetrical wound a dozen times on the fax, the burn was infinitely more commanding in real life. The raised, broiled flesh was perfectly delineated… the symbol flawlessly formed.

The corpse on the floor before Langdon was hideous. The late Leonardo Vetra lay on his back, stripped naked, his skin bluish-gray. His neck bones were jutting out where they had been broken, and his head was twisted completely backward, pointing the wrong way. His face was out of view, pressed against the floor. The man lay in a frozen puddle of his own urine, the hair around his shriveled genitals spidered with frost.

Langdon wondered if the intense chill now raking through his body was the air-conditioning or his utter amazement with the significance of what he was now staring at.

His heart pounded as he circled the body, reading the word upside down, reaffirming the genius of the symmetry. The symbol seemed even less conceivable now that he was staring at it.

"Not until I saw it branded on Mr. Vetra."

"Thousands," Kohler said. "Yours, however, contained references to Harvard, Oxford, a reputable publisher, as well as a list of related publications. As a scientist I have come to learn that information is only as valuable as its source. Your credentials seemed authentic."

"Yes."

Langdon nodded. "Had you heard the name before?"

"So you ran a web search for it?"

Kohler said nothing more. He simply stared, apparently waiting for Langdon to shed some light on the scene before them.

"Mr. Langdon?" Kohler's eyes probed expectantly.

"And the word returned hundreds of references, no doubt."

Langdon did not hear. He was in another world… his world, his element, a world where history, myth, and fact collided, flooding his senses. The gears turned.

"Only what I had time to read on your website. The word Illuminati means "the enlightened ones." It is the name of some sort of ancient brotherhood."

Langdon did not look up. His disposition now intensified, his focus total. "How much do you already know?"

Langdon's eyes were still riveted on the body.

"Mr. Langdon?"

Langdon looked up, glancing around the frozen flat. "Perhaps we should discuss this in a warmer place?"

Langdon frowned. The Illuminati history was by no means a simple one. I'll freeze to death trying to explain it. He gazed again at the brand, feeling a renewed sense of awe.

"This room is fine." Kohler seemed oblivious to the cold. "We'll talk here."

"So who are the Illuminati?" Kohler demanded.

Although accounts of the Illuminati emblem were legendary in modern symbology, no academic had ever actually seen it. Ancient documents described the symbol as an ambigram -- ambi meaning "both" -- signifying it was legible both ways. And although ambigrams were common in symbology-swastikas, yin yang, Jewish stars, simple crosses -- the idea that a word could be crafted into an ambigram seemed utterly impossible. Modern symbologists had tried for years to forge the word "Illuminati" into a perfectly symmetrical style, but they had failed miserably. Most academics had now decided the symbol's existence was a myth.

"Since the beginning of history," Langdon explained, "a deep rift has existed between science and religion. Outspoken scientists like Copernicus --"

"Were murdered," Kohler interjected. "Murdered by the church for revealing scientific truths. Religion has always persecuted science."

Yes, Langdon thought, who indeed? He began his tale.

"Yes. But in the 1500s, a group of men in Rome fought back against the church. Some of Italy's most enlightened men -- physicists, mathematicians, astronomers -- began meeting secretly to share their concerns about the church's inaccurate teachings. They feared that the church's monopoly on "truth" threatened academic enlightenment around the world. They founded the world's first scientific think tank, calling themselves "the enlightened ones.""

"The Illuminati."

"Yes," Langdon said. "Europe's most learned minds… dedicated to the quest for scientific truth."

Kohler fell silent.

"Of course, the Illuminati were hunted ruthlessly by the Catholic Church. Only through rites of extreme secrecy did the scientists remain safe. Word spread through the academic underground, and the Illuminati brotherhood grew to include academics from all over Europe. The scientists met regularly in Rome at an ultrasecret lair they called the Church of Illumination."

Langdon was certain Kohler would recognize the name. Even non scientists were familiar with the ill-fated astronomer who had been arrested and almost executed by the church for proclaiming that the sun, and not the earth, was the center of the solar system. Although his data were incontrovertible, the astronomer was severely punished for implying that God had placed mankind somewhere other than at the center of His universe.

Kohler coughed and shifted in his chair.

"Many of the Illuminati," Langdon continued, "wanted to combat the church's tyranny with acts of violence, but their most revered member persuaded them against it. He was a pacifist, as well as one of history's most famous scientists."

"His name was Galileo Galilei," Langdon said.

Kohler looked up. "Galileo?"

"Yes. Galileo was an Illuminatus. And he was also a devout Catholic. He tried to soften the church's position on science by proclaiming that science did not undermine the existence of God, but rather reinforced it. He wrote once that when he looked through his telescope at the spinning planets, he could hear God's voice in the music of the spheres. He held that science and religion were not enemies, but rather allies -- two different languages telling the same story, a story of symmetry and balance… heaven and hell, night and day, hot and cold, God and Satan. Both science and religion rejoiced in God's symmetry… the endless contest of light and dark." Langdon paused, stamping his feet to stay warm.

Kohler simply sat in his wheelchair and stared.

The million dollar question. Langdon cut to the chase. "Galileo's arrest threw the Illuminati into upheaval. Mistakes were made, and the church discovered the identities of four members, whom they captured and interrogated. But the four scientists revealed nothing… even under torture."

"Unfortunately," Langdon added, "the unification of science and religion was not what the church wanted."

"Of course not," Kohler interrupted. "The union would have nullified the church's claim as the sole vessel through which man could understand God. So the church tried Galileo as a heretic, found him guilty, and put him under permanent house arrest. I am quite aware of scientific history, Mr. Langdon. But this was all centuries ago. What does it have to do with Leonardo Vetra?"

Langdon nodded. "They were branded alive. On the chest. With the symbol of a cross."

"Torture?"

Kohler's eyes widened, and he shot an uneasy glance at Vetra's body.

"Then the scientists were brutally murdered, their dead bodies dropped in the streets of Rome as a warning to others thinking of joining the Illuminati. With the church closing in, the remaining Illuminati fled Italy."

"It's Islamic. It means 'adversary'… God's adversary. The church chose Islam for the name because it was a language they considered dirty." Langdon hesitated. "Shaitanis the root of an English word…Satan."

Langdon paused to make his point. He looked directly into Kohler's dead eyes. "The Illuminati went deep underground, where they began mixing with other refugee groups fleeing the Catholic purges-mystics, alchemists, occultists, Muslims, Jews. Over the years, the Illuminati began absorbing new members. A new Illuminati emerged. A darker Illuminati. A deeply anti-Christian Illuminati. They grew very powerful, employing mysterious rites, deadly secrecy, vowing someday to rise again and take revenge on the Catholic Church. Their power grew to the point where the church considered them the single most dangerous anti-Christian force on earth. The Vatican denounced the brotherhood as Shaitan."

"Shaitan?"

An uneasiness crossed Kohler's face.

Langdon's voice was grim. "Mr. Kohler, I do not know how this marking appeared on this man's chest… or why… but you are looking at the long -- lost symbol of the world's oldest and most powerful satanic cult."