The swimming pool was too warm, his bathroom too cold. He turned up his nose at the breakfast buffet and routinely sent back his food at dinner. The valets ruined the lapels of one of his suits, his massage at the spa had left him with an injured neck. He demanded the maids clean his suite promptly at eight each morning, and he remained in the room to supervise their work—his cash had been pinched at the Istanbul Hilton, he claimed, and he was not going to let it happen again in Cairo. The moment the maids left, the DO NOT DISTURB sign would appear on his door latch, where it would remain like a battle flag for the remainder of each day. Mr. Katubi wished only that he could hang a similar sign on his outpost in the lobby.

Each morning at ten Herr Klemp left the hotel armed with his tourist maps and guidebooks. The hotel drivers took to drawing straws to determine who would have the misfortune of serving as his guide for the day, for each outing seemed more calamitous than the last. The Egyptian Museum, he announced, needed a thorough cleaning. The Citadel he wrote off as a filthy old fort. At the pyramids of Giza he was nipped by a cantankerous camel. Upon his return from a visit to Coptic Cairo, Mr. Katubi asked if he enjoyed the Church of Saint Barbara. “Interesting,” said Herr Klemp, “but not as beautiful as our churches in Germany.”

On his fourth day, Mr. Katubi was standing at the entrance of the hotel as Herr Klemp came whirling out of the revolving doors, into a dust-filled desert wind.

“Good morning, Herr Klemp.”

“That is yet to be determined, Mr. Katubi.”

“Does Herr Klemp require a car this morning?”

“No, he does not.”

And with that he set out along the corniche, the tails of his supposedly “ruined” suit jacket flapping in the breeze like the mudguards of a lorry. Cairo was a city of remarkable resiliency, Mr. Katubi thought, but even Cairo was no match for a man like Herr Klemp.

GABRIEL SAW SOMETHING OF Europe in the grimy, decaying buildings along Talaat Harb Street. Then he remembered reading, in the guidebooks of Herr Klemp, that the nineteenth-century Egyptian ruler Khedive Ismail had conceived of turning Cairo into “Paris by the Nile” and had hired some of Europe’s finest architects to achieve his dream. Their handiwork was still evident in the neo-Gothic facades, the wrought-iron railings, and tall rectangular shuttered windows, though it had been undone by a century’s worth of pollution, weather, and neglect.

He came to a thunderous traffic circle. A sandaled boy tugged at his coat sleeve and invited him to visit his family’s perfume shop. “Nein, nein,” said Gabriel in the German of Herr Klemp, but he pushed past the child with the detached air of an Israeli used to fending off hawkers in the alleys of the Old City.