In some ways extremely so. During World War 2 an Arab-German spy called Eppler really did infiltrate Cairo, disguise himself as a British officer and recruit anti-British members of Egyptian society to help him gather intelligence, including a popular belly dancer and Egyptian army officer (and future president) Anwar Sadat. They genuinely did use the novel Rebecca to help encode their secret transmissions and a copy was seized by Australian forces during a successful raid on a German communications unit. However the value of the information they gathered remains disputed as they had severe difficulties communicating with German forces (the radio operators dedicated to their mission having been captured by the British) and were accused by many of spending their forged currency on hedonistic living rather than espionage. All the characters in the conspiracy were eventually arrested but released after the end of the war.
