The Key to Rebecca - Ken Follett

In this page-turning thriller set in World War II, Field Marshall Rommel leads a German invasion of Egypt. To aid in this effort, a spy is sent into the heart of the conflict. In
infiltrating English-controlled Egypt, this spy -- armed with only his wits and charm, and a copy of Daphne du Maurier's 'Rebecca' --  sets out to discover military secrets that could turn the war in favor of the Germans. Despite being a war-time story, there aren't too many military / historical references that would bog down a reader who is not all that fond of such details. Instead, the ensuing cat-and-mouse game will keep you riveted from beginning to end.