Langdon gave Sienna an impressed nod, apparently understanding her motives. If the police began questioning tourists, they might hear that Langdon and Sienna were headed for the costume gallery, which, according to the map on the wall before them, was at the far western end of the palace … as far as possible from the direction in which they were now headed.

“We need to get to that path over there,” Langdon said, motioning across an open plaza toward a walkway that ran down another hill, away from the palace. The peastone walkway was sheltered on the uphill side by massive hedges, providing plenty of cover from the authorities now descending the hill, only a hundred yards away.

Sienna calculated that their chances of getting across the open area to the sheltered path were very slim. Tourists were gathering there, watching the police with curiosity. The faint thrum of the drone became audible again, approaching in the distance.

“Now or never,” Langdon said, grabbing her hand and pulling her with him out into the open plaza, where they began winding through the crowd of gathering tourists. Sienna fought the urge to break into a run, but Langdon held firmly on to her, walking briskly but calmly through the throng.

When they finally reached the opening to the pathway, Sienna glanced back over her shoulder to see if they had been detected. The only police officers in sight were all facing the other way, their eyes turned skyward toward the sound of the incoming drone.

She faced front and hurried with Langdon down the path.

Before them now, the skyline of old Florence poked above the trees, visible directly ahead in the distance. She saw the red-tiled cupola of the Duomo and the green, red, and white spire of Giotto’s bell tower. For an instant, she could also make out the crenellated spire of the Palazzo Vecchio—their seemingly impossible destination—but as they descended the pathway, the high perimeter walls blotted out the view, engulfing them again.

By the time they reached the bottom of the hill, Sienna was out of breath and wondering if Langdon had any idea where they were going. The path led directly into a maze garden, but Langdon confidently turned left into a wide gravel patio, which he skirted, staying behind a hedge in the shadows of the overhanging trees. The patio was deserted, more of an employee parking lot than a tourist area.

“Where are we going?!” Sienna finally asked, breathless.

“Almost there.”

Almost where? The entire patio was enclosed by walls that were at least three stories tall. The only exit Sienna saw was a vehicle gateway on the left, which was sealed by a massive wrought-iron grate that looked like it dated back to the original palace in the days of marauding armies. Beyond the barricade, she could see police gathered in the Piazza dei Pitti.

Staying along the perimeter vegetation, Langdon pushed onward, heading directly for the wall in front of them. Sienna scanned the sheer face for any open doorway, but all she saw was a niche containing what had to be the most hideous statue she had ever seen.

Good God, the Medici could afford any artwork on earth, and they chose this?

The statue before them depicted an obese, naked dwarf straddling a giant turtle. The dwarf’s testicles were squashed against the turtle’s shell, and the turtle’s mouth was dribbling water, as if he were ill.

“I know,” Langdon said, without breaking stride. “That’s Braccio di Bartolo—a famous court dwarf. If you ask me, they should put him out back in the giant bathtub.”

Langdon turned sharply to his right, heading down a set of stairs that Sienna had been unable to see until now.

A way out?!

The flash of hope was short-lived.

As she turned the corner and headed down the stairs behind Langdon, she realized they were dashing into a dead end—a cul-de-sac whose walls were twice as high as the others.

Furthermore, Sienna now sensed that their long journey was about to terminate at the mouth of a gaping cavern … a deep grotto carved out of the rear wall. This can’t be where he’s taking us!

Over the cave’s yawning entrance, daggerlike stalactites loomed portentously. In the cavity beyond, oozing geological features twisted and dripped down the walls as if the stone were melting … morphing into shapes that included, to Sienna’s alarm, half-buried humanoids extruding from the walls as if being consumed by the stone. The entire vision reminded Sienna of something out of Botticelli’s Mappa dell’Inferno.

Langdon, for some reason, seemed unfazed, and continued running directly toward the cave’s entrance. He’d made a comment earlier about Vatican City, but Sienna was fairly certain there were no freakish caverns inside the walls of the Holy See.

As they drew nearer, Sienna’s eyes moved to the sprawling entablature above the entrance—a ghostly compilation of stalactites and nebulous stone extrusions that seemed to be engulfing two reclining women, who were flanked by a shield embedded with six balls, or palle, the famed crest of the Medici.

Langdon suddenly cut to his left, away from the entrance and toward a feature Sienna had previously missed—a small gray door to the left of the cavern. Weathered and wooden, it appeared of little significance, like a storage closet or room for landscaping supplies.

Langdon rushed to the door, clearly hoping he could open it, but the door had no handle—only a brass keyhole—and, apparently, could be opened only from within.

“Damn it!” Langdon’s eyes now shone with concern, his earlier hopefulness all but erased. “I had hoped—”

Without warning, the piercing whine of the drone echoed loudly off the high walls around them. Sienna turned to see the drone rising up over the palace and clawing its way in their direction.

Langdon clearly saw it, too, because he grabbed Sienna’s hand and dashed toward the cavern. They ducked out of sight in the nick of time beneath the grotto’s stalactite overhang.

A fitting end, she thought. Dashing through the gates of hell.

CHAPTER 28

A quarter mile to the east, Vayentha parked her motorcycle. She had crossed into the old city via the Ponte alle Grazie and then circled around to the Ponte Vecchio—the famed pedestrian bridge connecting the Pitti Palace to the old city. After locking her helmet to the bike, she strode out onto the bridge and mixed with the early-morning tourists.

A cool March breeze blew steadily up the river, ruffling Vayentha’s short spiked hair, reminding her that Langdon knew what she looked like. She paused at the stall of one of the bridge’s many vendors and bought an AMO FIRENZE baseball cap, pulling it low over her face.

She smoothed her leather suit over the bulge of her handgun and took up a position near the center of the bridge, casually leaning against a pillar and facing the Pitti Palace. From here she was able to survey all the pedestrians crossing the Arno into the heart of Florence.

Langdon is on foot, she told herself. If he finds a way around the Porta Romana, this bridge is his most logical route into the old city.

To the west, in the direction of the Pitti Palace, she could hear sirens and wondered if this was good or bad news. Are they still looking for him? Or have they caught him? As Vayentha strained her ears for some indication as to what was going on, a new sound suddenly became audible—a high-pitched whine somewhere overhead. Her eyes turned instinctively skyward, and she spotted it at once—a small remote-controlled helicopter rising fast over the palace and swooping down over the treetops in the direction of the northeast corner of the Boboli Gardens.

A surveillance drone, Vayentha thought with a surge of hope. If it’s in the air, Brüder has yet to find Langdon.

The drone was approaching fast. Apparently it was surveying the northeast corner of the gardens, the area closest to Ponte Vecchio and Vayentha’s position, which gave her additional encouragement.

If Langdon eluded Brüder, he would definitely be moving in this direction.

As Vayentha watched, however, the drone suddenly dive-bombed out of sight behind the high stone wall. She could hear it hovering in place somewhere below the tree line … apparently having located something of interest.

CHAPTER 29

Seek and ye shall find, Langdon thought, huddled in the dim grotto with Sienna. We sought an exit … and found a dead end.

The amorphous fountain in the center of the cave offered good cover, and yet as Langdon peered out from behind it, he sensed it was too late.

The drone had just swooped down into the walled cul-de-sac, stopping abruptly outside the cavern, where it now hovered at a standstill, only ten feet off the ground, facing the grotto, buzzing intensely like some kind of infuriated insect … awaiting its prey.

Langdon pulled back and whispered the grim news to Sienna. “I think it knows we’re here.”

The drone’s high-pitched whine was nearly deafening inside the cavern, the noise reflecting sharply off the stone walls. Langdon found it hard to believe they were being held hostage by a miniature mechanical helicopter, and yet he knew that trying to run from it was fruitless. So what do we do now? Just wait? His original plan to access what lay behind the little gray door had been a reasonable one, except he hadn’t realized the door was openable only from within.

As Langdon’s eyes adjusted to the grotto’s dark interior, he surveyed their unusual surroundings, wondering if there was any other exit. He saw nothing promising. The interior of the cavern was adorned with sculpted animals and humans, all in various stages of consumption by the strange oozing walls. Dejected, Langdon raised his eyes to the ceiling of stalactites hanging ominously overhead.

A good place to die.

The Buontalenti Grotto—so named for its architect, Bernardo Buontalenti—was arguably the most curious-looking space in all of Florence. Intended as a kind of fun house for young guests at the Pitti Palace, the three-chambered suite of caverns was decorated in a blend of naturalistic fantasy and Gothic excess, composed of what appeared to be dripping concretions and flowing pumice that seemed either to be consuming or exuding the multitude of carved figures. In the days of the Medici, the grotto was accented by having water flow down the interior walls, which served both to cool the space during the hot Tuscan summers and to create the effect of an actual cavern.

Langdon and Sienna were hidden in the first and largest chamber behind an indistinct central fountain. They were surrounded by colorful figures of shepherds, peasants, musicians, animals, and even copies of Michelangelo’s four prisoners, all of which seemed to be struggling to break free of the fluid-looking rock that engulfed them. High above, the morning light filtered down through an oculus in the ceiling, which had once held a giant glass ball filled with water in which bright red carp swam in the sunlight.

Langdon wondered how the original Renaissance visitors here would have reacted at the sight of a real-life helicopter—a fantastical dream of Italy’s own Leonardo da Vinci—hovering outside the grotto.

It was at that moment that the drone’s shrill whine stopped. It hadn’t faded away; rather, it had just … abruptly stopped.

Puzzled, Langdon peered out from behind the fountain and saw that the drone had landed. It was now sitting idle on the gravel plaza, looking much less ominous, especially because the stingerlike video lens on the front was facing away from them, off to one side, in the direction of the little gray door.

Langdon’s sense of relief was fleeting. A hundred yards behind the drone, near the statue of the dwarf and turtle, three heavily armed soldiers were now striding purposefully down the stairs, heading directly toward the grotto.

The soldiers were dressed in familiar black uniforms with green medallions on their shoulders. Their muscular lead man had vacant eyes that reminded Langdon of the plague mask in his visions.

I am death.

Langdon did not see their van or the mysterious silver-haired woman anywhere.

I am life.

As the soldiers approached, one of them stopped at the bottom of the stairs and turned around, facing backward, apparently to prevent anyone else from descending into this area. The other two kept coming toward the grotto.

Langdon and Sienna sprang into motion again—although probably only delaying the inevitable—shuffling backward on all fours into the second cavern, which was smaller, deeper, and darker. It, too, was dominated by a central piece of art—in this case, a statue of two intertwined lovers—behind which Langdon and Sienna now hid anew.

Veiled in shadow, Langdon carefully peered out around the base of the statue and watched their approaching assailants. As the two soldiers reached the drone, one stopped and crouched down to tend to it, picking it up and examining the camera.

Did the device spot us? Langdon wondered, fearing he knew the answer.

The third and last soldier, the muscular one with the cold eyes, was still moving with icy focus in Langdon’s direction. The man approached until he was nearly at the mouth of the cave. He’s coming in. Langdon prepared to pull back behind the statue and tell Sienna it was over, but in that instant, he witnessed something unexpected.

The soldier, rather than entering the grotto, suddenly peeled off to the left and disappeared.

Where is he going?! He doesn’t know we’re here?

A few moments later, Langdon heard pounding—a fist knocking on wood.

The little gray door, Langdon thought. He must know where it leads.

Pitti Palace security guard Ernesto Russo had always wanted to play European football, but at twenty-nine years old and overweight, he had finally begun to accept that his childhood dream would never come true. For the past three years, Ernesto had worked as a guard here at the Pitti Palace, always in the same closet-size office, always with the same dull job.

Ernesto was no stranger to curious tourists knocking on the little gray door outside the office in which he was stationed, and he usually just ignored them until they stopped. Today, however, the banging was intense and continuous.

Annoyed, he refocused on his television set, which was loudly playing a football rerun—Fiorentina versus Juventus. The knocking only grew louder. Finally, cursing the tourists, he marched out of his office down the narrow corridor toward the sound. Halfway there, he stopped at the massive steel grate that remained sealed across this hallway except at a few specific hours.