The Fallen Angel. Daniel Silva

its walls and ceiling, watched over by blue-uniformed gendarmes who seem to have no other job than to constantly plead for silenzio. To stand alone in the chapel, however, is to experience it as its namesake Pope Sixtus IV had intended. With the lights dimmed and the crowds absent, it is almost possible to hear the quarrels of conclaves past or to see Michelangelo atop his scaffolding putting the finishing touches on The Creation of Adam.

      On the western wall of the chapel is Michelangelo’s other Sistine masterwork, The Last Judgment. Begun thirty years after the ceiling was completed, it depicts the Apocalypse and the Second Coming of Christ, with all the souls of humanity rising or falling to meet their eternal reward or punishment in a swirl of color and anguish. The fresco is the first thing the cardinals see when they enter the chapel to choose a new pope, and on that morning it seemed the primary preoccupation of a single priest. Tall, lean, and strikingly handsome, he was cloaked in a black cassock with a magenta-colored sash and piping, handmade by an ecclesiastical tailor near the Pantheon. His dark eyes radiated a fierce and uncompromising intelligence, while the set of his jaw indicated he was a dangerous man to cross, which had the added benefit of being the truth. Monsignor Luigi Donati, private secretary to His Holiness Pope Paul VII, had few friends behind the walls of the Vatican, only occasional allies and sworn rivals. They often referred to him as a clerical Rasputin, the true power behind the papal throne, or “the Black Pope,” an unflattering reference to his Jesuit past. Donati didn’t mind. Though he was a devoted student of Ignatius and Augustine, he tended to rely more on the guidance of a secular Italian philosopher named Machiavelli, who counseled that it is far better for a prince to be feared than loved.

      Among Donati’s many transgressions, at least in the eyes of some members of the Vatican’s gossipy papal court, were his unusually close ties to the notorious spy and assassin Gabriel Allon. Theirs was a partnership that defied history and faith—Donati, the soldier of Christ, and Gabriel, the man of art who by accident of birth had been compelled to lead a clandestine life of violence. Despite those obvious differences, they had much in common. Both were men of high morals and principle, and both believed that matters of consequence were best handled in private. During their long friendship, Gabriel had acted as both the Vatican’s protector and a revealer of some of its darkest secrets—and Donati, the Holy Father’s hard man in black, had served as his willing accomplice. As a result, the two men had done much to quietly improve the tortured relationship between the world’s Catholics and their twelve million distant spiritual cousins, the Jews.

      Gabriel stood wordlessly at Donati’s side and gazed up at The Last Judgment. Near the center of the image, adjacent to the left foot of Christ, was one of two self-portraits Michelangelo had hidden within the frescoes. Here he had depicted himself as St. Bartholomew holding his own flayed skin, perhaps a not-so-subtle rejoinder to contemporary critics of his work.

      “I assume you’ve been here before,” said Donati, his sonorous voice echoing in the empty chapel.

      “Just once,” said Gabriel after a moment. “It was in the autumn of 1972, long before the restoration. I was posing as a German student traveling Europe. I came here in the afternoon and stayed until the guards forced me to leave. The next day …”

      His voice trailed off. The next day, with Michelangelo’s vision of the end times still fresh in his mind, Gabriel entered the foyer of a drab apartment building in the Piazza Annibaliano. Standing before the elevator, a bottle of fig wine in one hand and a copy of A Thousand and One Nights in the other, was a skinny Palestinian intellectual named Wadal Zwaiter. The Palestinian was a member of the terrorist group Black September, perpetrators of the Munich Olympics massacre, and for that he had been secretly sentenced to death. Gabriel had calmly asked Zwaiter to say his name aloud. Then he had shot him eleven times, once for each Israeli butchered at Munich. In the months that followed, Gabriel would assassinate five other members of Black September, the opening act of a distinguished career that lasted far longer than he ever intended. Working at the behest of his mentor, the legendary spymaster Ari Shamron, he had carried out some of the most fabled operations in the history of Israeli intelligence. Now, blown and battered, he had returned to Rome, to the place where it all began. And one of the few people in the world he could trust was a Catholic priest named Luigi Donati.

      Gabriel turned his back to The Last Judgment and gazed down the length of the rectangular chapel, past the frescoes by Botticelli and Perugino, toward the little potbellied stove where ballots were burned during papal conclaves. Then he recited, “ ‘The House which King Solomon built for the Lord was sixty cubits long, twenty cubits wide, and thirty cubits high.’ ”

      “Kings,” said Donati. “Chapter six, verse two.”

      Gabriel lifted his face toward the ceiling. “Your forefathers built this rather simple chapel to the exact dimensions of the Temple of Solomon for a reason. But why? Did they wish to pay tribute to their elder brothers the Jews? Or were they declaring that the old law had been superseded by the new law, that the ancient temple had been brought to Rome, along with the sacred contents of the Holy of Holies?”

      “Perhaps it was a little of both,” said Donati philosophically.

      “How diplomatic of you, Monsignor.”

      “I was trained as a Jesuit. Obfuscation is our strong suit.”

      Gabriel pondered his wristwatch. “It’s rather late in the morning for this place to be empty.”

      “Yes,” Donati said absently.

      “Where are the tourists, Luigi?”

      “For the moment, only the museums are open to the public.”

      “Why?”

      “We have a problem.”

      “Where?”

      Donati frowned and tilted his head toward the left.

      The stairwell leading from the glory of the Sistine Chapel to the most magnificent church in Christendom is decidedly ugly. A gray-green tube with slick cement walls, it deposited Gabriel and Donati into the Basilica, not far from the Chapel of the Pietà. In the center of the nave, a yellow tarpaulin was spread over the unmistakable form of a human corpse. Standing over it were two men. Gabriel knew them both. One was Colonel Alois Metzler, commandant of the Pontifical Swiss Guard. The other was Lorenzo Vitale, chief of the Corpo della Gendarmeria, the Vatican’s 130-member police force. In his previous life, Vitale had investigated government corruption cases for Italy’s powerful Guardia di Finanza. Metzler was retired Swiss Army. His predecessor, Karl Brunner, had been killed in the al-Qaeda terrorist attack on the Vatican.

      The two men looked up in unison and watched Gabriel crossing the nave at the side of the second-most powerful man in the Roman Catholic Church. Metzler was clearly displeased. He extended his hand toward Gabriel with the cold precision of a Swiss timepiece and nodded his head once in formal greeting. He was Donati’s equal in height and build but had been blessed by the Almighty with the jutting, angular face of a hound. He wore a dark gray suit, a white shirt, and a banker’s silver necktie. His receding hair was shorn to the length of stubble; small, rimless spectacles framed a pair of judgmental blue eyes. Metzler had friends inside the Swiss security service, which meant that he knew about Gabriel’s past exploits on the soil of his homeland. His presence in the Basilica was intriguing. Strictly speaking, dead bodies at the Vatican fell under the jurisdiction of the gendarmes, not the Swiss Guard—unless, of course, there was an element of papal security involved. If that were the case, Metzler would be free to poke his snout anywhere he pleased. Almost anywhere, thought Gabriel, for there were places behind the walls where even the commander of the palace guard was forbidden to enter.

      Donati exchanged a look with Vitale, then instructed the police chief to remove the tarpaulin. It was obvious the body had fallen from a great height. What remained was a split sack of skin filled with shattered bone and organs. Remarkably, the attractive face was largely intact. So was the identification badge around the neck. It stated that the bearer was an employee of the Vatican Museums. Gabriel didn’t bother to read