The Key to Rebecca

His code name: "The Sphinx." His mission: to send Rommel's advancing army the secrets that would unlock the doors to Cairo...and the ultimate Nazi triumph in the war. And in all of Cairo, only two people could stop this brilliant and ruthless Nazi master agent. One was a down-on-his-luck English officer no one would listen to. The other was a young Jewish girl... 

North Africa in the summer of 1942 and Rommel seems unbeatable. His secret weapon is Alex Wolff, master spy, and a deadly code buried in the pages of du Maurier’s novel, Rebecca.
Crossing the blazing Sahara, Wolff enters Cairo to steal British military plans. His pursuer, Major Vandam, engages the lovely Elene to lure him into range. As Rommel’s troops come closer to victory, the pursuit continues across the desert to a startling, explosive confrontation.

Ken Follett’s view
After the success of Eye of the Needle, my publishers would have liked me to write another World War Two spy story every year for 25 years. But I was only 29, and not ready to be put in a box. I was very firm that I was going to write anything that caught my fancy and the fancy of my readers. However, while researching Eye of the Needle, I had come across a wonderful true story.

There was a spy ring based on a house boat in Cairo in 1942 which involved a belly dancer and a British major she was having an affair with. The information at stake was crucial to the battles going on in the desert. The code used by the spies was based on one of the great suspense novels of all time, Rebecca, by Daphne du Maurier. The spycatcher in the story is trying to find the key to the Rebecca code. The Key to Rebecca was my third bestseller. After that, I really started believing that I was a success.