Maj. Michael Curragh (Robert Taylor), an Englishman, and American Melinda Greyton (Elizabeth Taylor) get married, but she has no idea he's working as a spy for the USSR. The Soviets quickly make it clear they're worried his identity will be revealed, so they tell Michael to kill his bride. The Soviet fears are well-founded, as Melinda is in the process of uncovering her husband's secret, and the newlyweds find themselves wrestling with the hazardous complications of espionage and love.