“The angry boys,” said Ibrahim. “And the imams, too. They’re worse than the young hotheads. They come from the Middle East. From Saudi Arabia. They preach Wahhabi Islam. The imam in our mosque told us that Professor Rosner deserved to die for what he had written about Muslims and the Prophet. I warned him to go into hiding, but he refused. He was very stubborn.”

Ibrahim stopped and leaned against the balustrade overlooking the sluggish black river. Gabriel looked at the Arab’s right hand and saw it was missing the last two fingers.

“Are you going to be sick?”

“I don’t think so.”

“Can you walk, Ibrahim? It’s better if we walk.”

The Arab nodded and they set off slowly along the riverbank. “I suppose you were the professor’s handler? That’s why you and your friend are digging frantically through his files.”

“What I’m doing inside his house is no business of yours.”

“Just do me a favor,” the Arab said. “If you come across my name, please do me the courtesy of dropping the document in question into the nearest shredder. I respected Professor Rosner very much, but I don’t want to end up like him. There are men in Amsterdam who will slit my throat if they knew I was helping him.”

“How long did you work for him?”

“A long time,” said Ibrahim. “But it wasn’t work. We were partners, Professor Rosner and I. We shared the same beliefs. We both believed the jihadists were destroying my religion. We both knew that if they weren’t stopped, they would destroy Holland, too.”

“Why work for Rosner? Why not the police?”

“Perhaps you can tell from my accent that I am Egyptian by birth. When one comes from Egypt, one has a natural fear of the police, secret or otherwise. I’ve lived in Holland for twenty-five years now. I am a citizen of this country, as are my wife and son. But to the Dutch police, and the rest of my countrymen, I will always be an allochtoon. An alien.”

“But you must have guessed Rosner was passing along some of your information to the police and the Dutch security service.”

“And to the Israeli secret service as well—or so it appears.” He looked at Gabriel and managed a sage smile. “I must confess that Israelis are not terribly popular in my home. My wife is a Palestinian. She fled to Egypt with her family in 1948 after al-Nakba and settled in Cairo. I’ve heard about the suffering of the Palestinian people every night at my dinner table for thirty-five years now. My son drank it with his mother’s milk. He is Egyptian and Palestinian, a volatile mix.”

“Is this the reason you followed me tonight, Ibrahim—to engage in a debate about the Palestinian Diaspora and the crimes of Israel’s founders?”