Don’t let her aboard!

As he closed the gap, he could see that Sienna’s appeal was directed at a young man who stood at the helm of a sleek powerboat that was just preparing to pull away from the dock. The man was smiling but politely shaking his head no. Sienna continued gesticulating, but the boater appeared to decline with finality, and he turned back to his controls.

As Langdon dashed closer, Sienna glanced at him, her face a mask of desperation. Below her, the boat’s twin outboards revved, churning the water and moving the craft away from the dock.

Sienna was suddenly airborne, leaping off the dock over the open water. She landed with a crash on the boat’s fiberglass stern. Feeling the impact, the driver turned with an expression of disbelief on his face. He yanked back the throttle, idling the boat, which was now twenty yards from the dock. Yelling angrily, he marched back toward his unwanted passenger.

As the driver advanced on her, Sienna effortlessly stepped aside, seizing the man’s wrist and using his own momentum to launch him up and over the stern gunwale. The man plunged headlong into the water. Moments later, he rose to the surface, sputtering and thrashing wildly, and shouting a string of what were no doubt Turkish obscenities.

Sienna seemed detached as she tossed a flotation cushion into the water, moved to the helm of the boat, and pushed the dual throttles forward.

The engines roared and the boat sped off.

Langdon stood on the dock, catching his breath as he watched the sleek white hull skimming away across the water, becoming a ghostly shadow in the night. Langdon raised his eyes toward the horizon and knew that Sienna now had access not only to the distant shores, but also to an almost endless web of waterways that stretched from the Black Sea to the Mediterranean.

She’s gone.

Nearby, the boat’s owner climbed out of the water, got to his feet, and hurried off to call the police.

Langdon felt starkly alone as he watched the lights of the stolen boat growing faint. The whine of the powerful engines was growing distant as well.

And then the engines faded abruptly to silence.

Langdon peered into the distance. Did she kill the motor?

The boat’s lights seemed to have stopped receding and were now bobbing gently in the small waves of the Golden Horn. For some unknown reason, Sienna Brooks had stopped.

Did she run out of gas?

He cupped his hands and listened, now able to hear the faint thrum of her engines idling.

If she’s not out of gas, what is she doing?

Langdon waited.

Ten seconds. Fifteen seconds. Thirty seconds.

Then, without warning, the engines revved up again, reluctantly at first, and then more decidedly. To Langdon’s bewilderment, the boat’s lights began banking into a wide turn, and the bow swung around toward him.

She’s coming back.

As the boat approached, Langdon could see Sienna at the wheel, staring blankly ahead. Thirty yards away, she throttled down and eased the boat safely back to the dock it had just left. Then she killed the engines.

Silence.

Above her, Langdon stared down in disbelief.

Sienna never looked up.

Instead, she buried her face in her hands. She began trembling, her shoulders hunched and shuddering. When she finally looked at Langdon, her eyes were overflowing with tears.

“Robert,” she sobbed. “I can’t run away anymore. I have nowhere left to go.”

CHAPTER 96

It’s out.

Elizabeth Sinskey stood at the bottom of the cistern stairwell and gazed at the void of the evacuated cavern. Her breathing felt strained through the respirator she was wearing. Although she had probably already been exposed to whatever pathogen might be down here, Sinskey felt relieved to be wearing a hazmat suit as she and the SRS team entered the desolate space. They were dressed in bulbous white jumpsuits that locked into airtight helmets, and the group looked like a team of astronauts breaching an alien spacecraft.

Sinskey knew that upstairs on the street, hundreds of frightened concertgoers and musicians were huddling in confusion, many being treated for injuries suffered in the stampede. Others had fled the area entirely. She felt lucky to have escaped with only a bruised knee and a broken amulet.

Only one form of contagion travels faster than a virus, Sinskey thought. And that’s fear.

The doors upstairs were now locked, hermetically sealed, and guarded by local authorities. Sinskey had anticipated a jurisdictional showdown with the arriving local police, but any potential conflicts had evaporated instantly when they saw the SRS team’s biohazard gear and heard Sinskey’s warnings of a possible plague.

We’re on our own, the director of the WHO thought, staring out at the forest of columns reflected in the lagoon. Nobody wants to come down here.

Behind her, two agents were stretching a huge polyurethane sheet across the bottom of the stairwell and sealing it to the wall with a heat gun. Two others had found an open area of boardwalk planks and had begun setting up an array of electronic gear as if preparing to analyze a crime scene.

That’s exactly what this is, Sinskey thought. A crime scene.

She again pictured the woman in the wet burka who had fled the cistern. By all appearances, Sienna Brooks had risked her own life in order to sabotage the WHO’s containment efforts and fulfill Zobrist’s twisted mission. She came down here and broke the Solublon bag …

Langdon had chased Sienna off into the night, and Sinskey had still not received word regarding what had happened to either of them.

I hope Professor Langdon is safe, she thought.

Agent Brüder stood dripping on the boardwalk, staring blankly out at the inverted head of Medusa and wondering how to proceed.

As an SRS agent, Brüder had been trained to think on the macro-cosmic level, setting aside any immediate ethical or personal concerns and focusing on saving as many lives as possible over the long term. Threats to his own health had barely registered on him until this moment. I waded into this stuff, he thought, chastising himself for the risky action he had taken and yet knowing he’d had little choice. We needed an immediate assessment.

Brüder forced his thoughts to the task at hand—implement Plan B. Unfortunately, in a containment crisis, Plan B was always the same: widen the radius. Fighting communicable disease was often like fighting a forest fire: sometimes you had to drop back and surrender a battle in hopes of winning the war.

At this point, Brüder had still not given up the idea that a full containment was possible. Most likely Sienna Brooks had ruptured the bag only minutes before the mass hysteria and evacuation. If that were true, even though hundreds of people had fled the scene, everyone might have been located far enough away from the source to avoid contamination.

Everyone except Langdon and Sienna, Brüder realized. Both of whom were here at ground zero, and are now someplace out in the city.

Brüder had another concern as well—a gap in logic that continued to nag at him. While in the water, he had never found the actual breached Solublon bag. It seemed to Brüder that if Sienna had broken the bag—by kicking it or ripping it or whatever she had done—he would have found the damaged, deflated remnants floating somewhere in the area.

But Brüder had found nothing. Any remains of the bag seemed to have vanished. Brüder strongly doubted that Sienna would have carried off the Solublon bag with her, since by this point it would have been no more than a slimy, dissolving mess.

So where did it go?

Brüder had an uneasy sense that he was missing something. Even so, he focused on a new containment strategy, which required him to answer one critical question.

What is the contagion’s current dispersal radius?

Brüder knew the question would be answered in a matter of minutes. His team had set up a series of portable virus-detection devices along the boardwalks at increasing distances from the lagoon. These devices—known as PCR units—used what was called a polymerase chain reaction to detect the presence of viral contamination.

The SRS agent remained hopeful. With no movement of the water in the lagoon, and the passage of very little time, he was confident that the PCR devices would detect a relatively small region of contamination, which they could then attack with chemicals and the use of suction.

“Ready?” a technician called out through a megaphone.

Agents stationed around the cistern gave the thumbs-up.

“Run your samples,” the megaphone crackled.

Throughout the cavern, analysts crouched down and started their individual PCR machines. Each device began analyzing a sample from the point at which its operator was located on the boardwalk, spaced in ever-widening arcs around Zobrist’s plaque.

A hush fell across the cistern as everyone waited, praying to see only green lights.

And then it happened.

On the machine closest to Brüder, a virus-detection light began flashing red. His muscles tensed, and his eyes shifted to the next machine.

It, too, began blinking red.

No.

Stunned murmurs reverberated throughout the cavern. Brüder watched in horror as, one by one, every PCR device began blinking red, all the way across the cistern to the entrance.

Oh, God … he thought. The sea of blinking red detection lights painted an unmistakable picture.

The radius of contamination was enormous.

The entire cistern was teeming with virus.

CHAPTER 97

Robert Langdon stared down at Sienna Brooks, huddled at the wheel of the stolen powerboat, and struggled to make sense of what he had just witnessed.

“I’m sure you despise me,” she sobbed, looking up at him through tearful eyes.

“Despise you?!” Langdon exclaimed. “I don’t have the slightest idea who you are! All you’ve done is lie to me!”

“I know,” she said softly. “I’m sorry. I’ve been trying to do the right thing.”

“By releasing a plague?”

“No, Robert, you don’t understand.”

“I do understand!” Langdon replied. “I understand you waded out into the water to break that Solublon bag! You wanted to release Zobrist’s virus before anyone could contain it!”

“Solublon bag?” Sienna’s eyes flashed confusion. “I don’t know what you’re talking about. Robert, I went to the cistern to stop Bertrand’s virus … to steal it and make it disappear forever … so nobody could ever study it, including Dr. Sinskey and the WHO.”

“Steal it? Why keep it from the WHO?”

Sienna took a long breath. “There’s so much you don’t know, but it’s all moot now. We arrived much too late, Robert. We never had a chance.”

“Of course we had a chance! The virus was not going to be released until tomorrow! That’s the date Zobrist chose, and if you hadn’t gone into the water—”

“Robert, I didn’t release the virus!” Sienna yelled. “When I went into the water, I was trying to find it, but it was too late. There was nothing there.”

“I don’t believe you,” Langdon said.

“I know you don’t. And I don’t blame you.” She reached into her pocket and pulled out a soggy pamphlet. “But maybe this will help.” She tossed the paper to Langdon. “I found this just before I waded into the lagoon.”

He caught it and opened it up. It was a concert program for the cistern’s seven performances of the Dante Symphony.

“Look at the dates,” she said.

Langdon read the dates and then reread them, puzzled by what he saw. For some reason, he had been under the impression that this evening’s performance was opening night—the first of seven performances to be given during the week, designed to lure people into a plague-infested cistern. This program, however, told a different story.

“Tonight was closing night?” Langdon asked, glancing up from the paper. “The orchestra has been playing all week?”

Sienna nodded. “I was as surprised as you are.” She paused, her eyes somber. “The virus is already out, Robert. It has been for a week.”

“That can’t be true,” Langdon argued. “Tomorrow is the date. Zobrist even made a plaque with tomorrow’s date on it.”

“Yes, I saw the plaque in the water.”

“Then you know he was fixated on tomorrow.”

Sienna sighed. “Robert, I knew Bertrand well, better than I ever admitted to you. He was a scientist, a results-oriented person. I now realize that the date on the plaque is not the virus’s release date. It’s something else, something more important to his goal.”

“And that would be …?”

Sienna gazed up solemnly from the boat. “It’s a global-saturation date—a mathematical projection of the date after which his virus will have propagated across the world … and infected every individual.”

The prospect sent a visceral tremor through Langdon, and yet he couldn’t help but suspect that she was lying. Her story contained a fatal flaw, and Sienna Brooks had already proven she’d lie about anything.

“One problem, Sienna,” he said, staring down at her. “If this plague has already spread all over the world, then why aren’t people getting sick?”

Sienna glanced away, suddenly unable to meet his gaze.

“If this plague has been out a week,” Langdon repeated, “why aren’t people dying?”

She turned slowly back to him. “Because …” she began, the words catching in her throat. “Bertrand didn’t create a plague.” Her eyes welled up again with tears. “He created something far more dangerous.”

CHAPTER 98

Despite the flow of oxygen that passed through her respirator, Elizabeth Sinskey felt light-headed. Five minutes had passed since Brüder’s PCR devices had revealed the horrifying truth.

Our window for containment closed long ago.

The Solublon bag had apparently dissolved sometime last week, most likely on the opening night of the concert, which Sinskey now knew had been playing for seven nights straight. The few remaining shreds of Solublon attached to the tether had not disappered, only because they had been coated with an adhesive to help secure them to the tether’s clasp.