On the final night they showed her a series of computer-generated photo illustrations of how bin Shafiq might look now. Bin Shafiq with a beard. Bin Shafiq with a balding pate. Bin Shafiq with a gray wig. With a black wig. With curly hair. With no hair at all. With his sharp Bedouin features softened by a plastic surgeon. But it was the wounded arm that would be her most valuable clue to his identity, Gabriel told her. The scar on the inside of his forearm he would never show. The slightly withered hand that he would never offer and keep safely tucked away, hidden from infidel eyes.

“We know he’s concealed somewhere within Zizi’s empire,” Gabriel said. “He might come as an investment banker or a portfolio manager. He might come as a real estate developer or a pharmaceutical executive. He might come in a month. He might come in a year. He might never come. But if he does come, you can be certain he’ll be well mannered and worldly and seem like anything but a professional terrorist. Don’t look for a terrorist or someone who acts like a terrorist. Just look for a man.”

He gathered up the photo illustrations. “We want to know about everyone who moves in and out of Zizi’s orbit. We want you to gather as many names as you can. But this is the man we’re looking for.” Gabriel placed a photograph on the table in front of her. “This is the man we want.” Another photograph. “This is the man we’re after.” Another. “He’s the reason we’re all here instead of being home with our families and our children.” Another. “He’s the reason we asked you to give up your life and join us.” Another. “If you see him, you’re to get us the name he’s using and the company he’s working for. Get the country of his passport if you can.” Another photograph. “If you’re not sure it’s him, it doesn’t matter. Tell us. If it doesn’t turn out to be him, it doesn’t matter. Tell us. Nothing happens based on your word alone. No one gets hurt because of you, Sarah. You’re only the messenger.”

“And if I give you a name?” she asked. “What happens then?”

Gabriel looked at his watch. “I think it’s time Sarah and I had a word in private. Would you all excuse us?”

HE LED HER upstairs to his studio and switched on the halogen lamps. Marguerite Gachet glowed seductively under the intense white light. Sarah sat down in an ancient wingchair; Gabriel slipped on his magnifying visor and prepared his palette.

“How much longer?” she asked.