[Starring] James Mason and Valerie Hobson
This film, based on the story of 'The Eunuch of Stamboul', by Dennis Wheatley and George A. Hill, is a spy melodrama set against the background of the ancient Turkish city of Stamboul.

How the story goes:
Larry Destime and Peter Carew, officers in the Guards, attend a boat club ball and rescue Diana, beautiful daughter of Sir George Duncannon, from the advances of Prince Ali, whom Larry knocks out. To avoid a diplomatic incident, the two officers are forced to resign their commissions and Sir George offers Larry the managership of his tobacco depot in Turkey. He knows that Larry speaks the language and realises, because of disquieting rumours about the activities of the Turkish Government, that it is essential for him to have a reliable man out there to safeguard his interests.
Out on the job, Larry meets and falls in love with a beautiful Russian girl, Tania, who is informed by Kazdim the all-powerful Eunuch of Stamboul, that she must find out Larry's reasons for visiting the citadel - but that is enough to be going on with.