Leo Cauffield, chief of British counterespionage, fails by a whisker to arrest two fellow Cambridge-graduated spies who just manage to defect to Moscow, resigns, and becomes a journalist. In Beirut, home of his Islam-converted father, Leo seduce s Sally Tyler and convinces her to divorce her husband for him. With childre n from both marriages, their temporary happiness is cut short a few years later, when Leo suddenly disappears; Sally soon learns he’s suspected of having defected to Moscow too, which she refuses to believe, but will she be forced to, whilst Western secret service s want Leo back, dead or alive.