I let her go on before I followed. She was undoubtedly correct. The passengers who opted for the Aswan cruise had to be innocents. The Cairo-bound crowd was the one to be watched.

The last of the shore-tour group was leaving the lobby when I got there, to find my escort waiting – Schmidt, Larry, and the inevitable Ed. The open doors led, not to the gangplank but to the lobby of another cruise ship. We had to pass throngh it to reach the dock. Sometimes there were as many as five moored abreast, Larry said.

The car waiting for us looked as if it had been custom-built for a sheikh, and I felt sure the tinted glass was bulletproof. Ed rode up in front with the chauffeur, which left the three of us in splendid isolation in the back. There was room for the sheikh’s four legal wives and a couple of concubines.

The Shari el-Bahr el-Nil, familiarly known as the corniche, runs along the riverbank. It is a handsome boulevard with a tree-lined promenade on one side and on the other a fascinating mélange of ancient temples and modern hotels and souvenir shops. We passed the Winter Palace, where our fellow passengers were to stay, and went on for another mile or so before turning into a narrow driveway. The walls ahead resembled those of a fort. They were topped with wicked-looking coils of barbed wire, and the closed gates appeared to be fashioned of steel. They swung slowly open as the car approached.

I pinched Schmidt. ‘You know, Schmidt, I don’t think we’re in Kansas any more.’

It was like the sudden switch from black and white to Technicolor in the film. For the past mile we had driven past high-rise hotels and storefronts adorned with garish signs in Arabic and half a dozen other languages. Behind these grim walls were green lawns and flower beds bright with blossoms. Winding paths led between the trees to the buildings whose rooflines showed through the leaves. The main house was a low, unpretentious structure of pale brick. Two storeys in height, it was roofed with red tiles and had balconies sprouting out from the upper floor.

Schmidt didn’t answer. He was gaping in childish pleasure.

When we got out of the car a bunch of Munchkins descended on us. Two of them carried my bags up the stairs to my room, where a smiling, grey-haired maid was waiting to unpack for me. She expostulated when I insisted on helping, but I didn’t want her to see the condition of my underwear. I finally got rid of her by allowing her to carry off an armful of garments to be pressed.