==comment==From and IMDb commenter: "Based on real events this effort from Joseph Mankiewicz is a lesson in tautness without histrionics. It is something of an intriguing watch knowing that the lead character really was selling top secret information to the Germans, yet they {thankfully} never acted on any of the info they bought. The film has a wonderful paced structure and is splendidly shot, and the direction somehow manages to give added feeling to the dastardly deeds unfolding on the screen. The trump card is James Mason as the cold hearted money mad Cicero, he manages to blend charm and sophistication into a character that we know is as low as a snakes belly, it's a special performance from Mason in what is a great spy story, with plenty of suspense and a corking ending to round it all off."
Apparently it shows up on the History Channel every now and then.