Gabriel Allon had confronted evil in many forms: terrorists, murderous Russian arms dealers, professional assassins who shed the blood of strangers for briefcases filled with cash. But none could compare to the genocidal evil of the men and women who had carried out the single greatest act of mass murder in history. They had been a constant if unacknowledged presence inside Gabriel’s childhood home in the Jezreel Valley of Israel. And now that night had fallen over Amsterdam, they had crept into the suite at the Ambassade Hotel. Unable to bear their company any longer, he stood abruptly and informed Eli Lavon and Chiara that he needed to continue the conversation outside. They drifted along the banks of the Herengracht through yellow lamplight, Gabriel and Lavon shoulder to shoulder, Chiara trailing several paces behind.

“She’s too close.”

“She’s not tailing us, Eli. She’s just watching our back.”

“It doesn’t matter. She’s still too close.”

“Shall we stop so you can give her a bit of instruction?”

“She never listens to me. She’s unbelievably stubborn. And far too pretty for street work.” Lavon gave Gabriel a sideways glance. “I’ll never understand what she saw in a fossil like you. It must have been your natural charm and cheerful disposition.”

“You were about to tell me more about Kurt Voss.”

Lavon paused to allow a bicycle to pass. It was ridden by a young woman who was steering with one hand and sending a text message with the other. Lavon gave a fleeting smile, then resumed his lecture.

“Keep one thing in mind, Gabriel. We know a great deal about Voss now, but in the aftermath of the war we barely knew the bastard’s name. And by the time we fully understood the true nature of his crimes, he’d disappeared.”

“Where did he go?”

“Argentina.”

“How did he get there?”

“How do you think?”

“The Church?”

“But of course.”

Gabriel shook his head slowly. To this day, historians bitterly debated whether Pope Pius XII, the controversial wartime pontiff, had helped the Jews or turned a blind eye to their suffering. But it was Pius’s actions after the war that Gabriel found most damning. The Holy Father never uttered a single word of sorrow or regret over the murder of six million human beings and seemed far more concerned about the perpetrators of the crime than its victims. Not only was the pope an outspoken critic of the Nuremburg trials, he allowed the good offices of the Vatican to be used for one of history’s greatest mass flights from justice. Known as the Vatican ratline, it helped hundreds, if not thousands, of Nazi war criminals to escape to sanctuaries in South America and the Middle East.