"Terra firma," the pilot announced as they touched down. He exited and opened the sliding door for Langdon and Vittoria.

The Vatican's helipad, for reasons of safety and noise control, is located in the northwest tip of Vatican City, as far from St. Peter's Basilica as possible.

Langdon descended from the craft and turned to help Vittoria, but she had already dropped effortlessly to the ground. Every muscle in her body seemed tuned to one objective -- finding the antimatter before it left a horrific legacy.

After stretching a reflective sun tarp across the cockpit window, the pilot ushered them to an oversized electric golf cart waiting near the helipad. The cart whisked them silently alongside the country's western border -- a fifty-foot-tall cement bulwark thick enough to ward off attacks even by tanks. Lining the interior of the wall, posted at fifty-meter intervals, Swiss Guards stood at attention, surveying the interior of the grounds. The cart turned sharply right onto Via della Osservatorio. Signs pointed in all directions:

PALAZZIO GOVERNATORIO

COLLEGIO ETHIOPIANA

BASILICA SAN PIETRO

They accelerated up the manicured road past a squat building markedRADIO VATICANA. This, Langdon realized to his amazement, was the hub of the world's most listened -- to radio programming -- Radio Vaticana -- spreading the word of God to millions of listeners around the globe.

CAPELLA SISTINA

"Attenzione,"the pilot said, turning sharply into a rotary.

As the cart wound round, Langdon could barely believe the sight now coming into view. Giardini Vaticani, he thought. The heart of Vatican City. Directly ahead rose the rear of St. Peter's Basilica, a view, Langdon realized, most people never saw. To the right loomed the Palace of the Tribunal, the lush papal residence rivaled only by Versailles in its baroque embellishment. The severe-looking Governatorato building was now behind them, housing Vatican City's administration. And up ahead on the left, the massive rectangular edifice of the Vatican Museum. Langdon knew there would be no time for a museum visit this trip.

"Where is everyone?" Vittoria asked, surveying the deserted lawns and walkways.

The guard checked his black, military-style chronograph -- an odd anachronism beneath his puffy sleeve. "The cardinals are convened in the Sistine Chapel. Conclave begins in a little under an hour."

"Banned from the city for secrecy and security until the conclave concludes."

"And when does it conclude?"

After parking the cart on the wide lawn directly behind St. Peter's Basilica, the guard escorted Langdon and Vittoria up a stone escarpment to a marble plaza off the back of the basilica. Crossing the plaza, they approached the rear wall of the basilica and followed it through a triangular courtyard, across Via Belvedere, and into a series of buildings closely huddled together. Langdon's art history had taught him enough Italian to pick out signs for the Vatican Printing Office, the Tapestry Restoration Lab, Post Office Management, and the Church of St. Ann. They crossed another small square and arrived at their destination.

Langdon nodded, vaguely recalling that before conclave the cardinals spent two hours inside the Sistine Chapel in quiet reflection and visitations with their fellow cardinals from around the globe. The time was meant to renew old friendships among the cardinals and facilitate a less heated election process. "And the rest of the residents and staff?"

The guard shrugged. "God only knows." The words sounded oddly literal.

The Office of the Swiss Guard is housed adjacent to Il Corpo di Vigilanza, directly northeast of St. Peter's Basilica. The office is a squat, stone building. On either side of the entrance, like two stone statues, stood a pair of guards.

Langdon had to admit, these guards did not look quite so comical. Although they also wore the blue and gold uniform, each wielded the traditional "Vatican long sword" -- an eight-foot spear with a razor-sharp scythe -- rumored to have decapitated countless Muslims while defending the Christian crusaders in the fifteenth century.

The pilot waved them off. "Il comandante vuole vederli subito."

The guards frowned. Reluctantly they stepped aside.

As Langdon and Vittoria approached, the two guards stepped forward, crossing their long swords, blocking the entrance. One looked up at the pilot in confusion."I pantaloni," he said, motioning to Vittoria's shorts.

Inside, the air was cool. It looked nothing like the administrative security offices Langdon would have imagined. Ornate and impeccably furnished, the hallways contained paintings Langdon was certain any museum worldwide would gladly have featured in its main gallery.

It was one of the most horrific tragedies in Renaissance art. In 1857, Pope Pius IX decided that the accurate representation of the male form might incite lust inside the Vatican. So he got a chisel and mallet and hacked off the genitalia of every single male statue inside Vatican City. He defaced works by Michelangelo, Bramante, and Bernini. Plaster fig leaves were used to patch the damage. Hundreds of sculptures had been emasculated. Langdon had often wondered if there was a huge crate of stone penises someplace.

Langdon and Vittoria followed the white marble treads as they descended between a gauntlet of nude male sculptures. Each statue wore a fig leaf that was lighter in color than the rest of the body.

The pilot pointed down a steep set of stairs. "Down, please."

The Great Castration, Langdon thought.

Beyond the threshold was absolute mayhem.

"Here," the guard announced.

They reached the bottom of the stairs and dead-ended at a heavy, steel door. The guard typed an entry code, and the door slid open. Langdon and Vittoria entered.