She quickly told Langdon about the call from Prince Julián’s office. “All I really know is that the museum’s front desk got a call that originated in the Royal Palace of Madrid. Technically, that call could have been from anyone there claiming to be Julián’s assistant.”

Langdon nodded. “That may be why the person chose to relay the request to you rather than talk to you directly. Any idea who might be involved?” Considering Edmond’s history with Valdespino, Langdon was inclined to look toward the bishop himself.

“It could be anybody,” Ambra said. “It’s a delicate time in the palace right now. With Julián taking center stage, a lot of the old advisers are scrambling to find favor and gain Julián’s ear. The country is changing, and I think a lot of the old guard are desperate to retain power.”

“Well, whoever is involved,” Langdon said, “let’s hope they don’t figure out we’re trying to locate Edmond’s password and release his discovery.”

As he spoke the words, Langdon felt the stark simplicity of their challenge.

He also sensed its blunt peril.

Edmond was murdered to keep this information from being released.

For an instant, Langdon wondered if his safest option might be simply to fly directly home from the airport and let someone else handle all this.

Safe, yes, he thought, but an option … no.

Langdon felt a profound sense of duty toward his old student, along with moral outrage that a scientific breakthrough could be so brutally censored. He also felt a deep intellectual curiosity to learn exactly what Edmond had discovered.

And finally, Langdon knew, there is Ambra Vidal.

The woman was clearly in crisis, and when she had looked into his eyes and pleaded for help, Langdon had sensed in her a deep well of personal conviction and self-reliance … yet he had also seen heavy clouds of fear and regret. There are secrets there, he sensed, dark and confining. She is reaching out for help.

Ambra raised her eyes suddenly, as if sensing Langdon’s thoughts. “You look cold,” she said. “You need your jacket back.”

He smiled softly. “I’m fine.”

“Are you thinking you should leave Spain as soon as we get to the airport?”

Langdon laughed. “Actually, that did cross my mind.”

“Please don’t.” She reached out to the railing and placed her soft hand on top of his. “I’m not sure what we’re facing tonight. You were close to Edmond, and he told me more than once how much he valued your friendship and trusted your opinion. I’m scared, Robert, and I really don’t think I can face this alone.”

Ambra’s flashes of unguarded candor were startling to Langdon, and yet also utterly captivating. “Okay,” he said, nodding. “You and I owe it to Edmond and, frankly, to the scientific community, to find that password and make his work public.”

Ambra smiled softly. “Thank you.”

Langdon glanced behind the boat. “I imagine your Guardia agents have realized by now that we’ve left the museum.”

“No doubt. But Winston was quite impressive, wasn’t he?”

“Mind-boggling,” Langdon replied, only now starting to grasp the quantum leap Edmond had made in the development of AI. Whatever Edmond’s “proprietary breakthrough technologies” had been, clearly he had been poised to usher in a brave new world of human–computer interaction.

Tonight, Winston had proven himself a faithful servant to his creator as well as an invaluable ally to Langdon and Ambra. In a matter of minutes, Winston had identified a threat on the guest list, attempted to thwart Edmond’s assassination, identified the getaway car, and facilitated Langdon and Ambra’s escape from the museum.

“Let’s hope Winston phoned ahead to alert Edmond’s pilots,” Langdon said.

“I’m sure he did,” Ambra said. “But you’re right. I should call Winston to double-check.”

“Hold on,” Langdon said, surprised. “You can call Winston? When we left the museum and went out of range, I thought …”

Ambra laughed and shook her head. “Robert, Winston is not physically located inside the Guggenheim; he is located in a secret computer facility somewhere and accessed remotely. Do you really think Edmond would build a resource like Winston and not be able to communicate with him at all times, anywhere in the world? Edmond talked to Winston all the time—at home, traveling, out for walks—the two of them could connect at any moment with a simple phone call. I’ve seen Edmond chat for hours with Winston. Edmond used him like a personal assistant—to call for dinner reservations, to coordinate with his pilots, to do anything that needed doing, really. In fact, when we were mounting the museum show, I talked to Winston quite often myself by phone.”

Ambra reached inside the pocket of Langdon’s tails jacket and pulled out Edmond’s turquoise-covered phone, flicking it on. Langdon had powered it down in the museum to save its battery.

“You should turn on your phone too,” she said, “so we both have access to Winston.”

“You’re not worried about being tracked if we turn these on?”

Ambra shook her head. “The authorities haven’t had time to get the necessary court order, so I think it’s worth the risk—especially if Winston can update us on the Guardia’s progress and the situation at the airport.”

Uneasy, Langdon turned on his phone and watched it come to life. As the home screen materialized, he squinted into the light and felt a twinge of vulnerability, as if he had just become instantly locatable to every satellite in space.