There is a brief scene in Stamboul Quest, as Leo G. Carroll's character stops by the entrance to a building in Berlin to look at the metal plaques attached by the entrance, identifying the business occupants. In German, the signs identify a notary, a lawyer and, in German and English, an American Dentist. Carroll paused for only a few seconds, and if not for a screen capture I made, I would not be able to check out the attention to detail that the art director or prop man put into this minor set piece. When I visited Berlin, I saw business plaques just like those in this movie, made in Culver City, which is a long way from Berlin. From the prologue at the start, describing in general terms the difference between espionage and counter-espionage, to Lionel Atwill's fine portrayal of a spymaster, Stamboul Quest is a picture ahead of its time. Transmitting coded messages in a tooth filling is not a procedure you see in many movies. There is also a love story, Myrna Loy's character, Fraulein Doktor, falling in love with the American medical student (George Brent) who gets entangled with the spies by going to the American Dentist when the counterespionage agents raid the office. 25 years later, Leo G. Carroll was the spymaster who takes advantage of Cary Grant being mistaken for George Kaplan, a fictitious agent created to catch real spies. Carroll and company notice the gallows humor in Grant's predicament, just as Atwill also finds humor in George Brent's character mistakenly getting locked up for being a spy. George Brent, on loan to MGM after going on suspension at Warners (Jack Warner must have liked Brent, since Warners was a studio that had a track record ruining actor's careers by refusing to loan them out to other studios on reasonable terms e.g. Wayne Morris blocked from working in The Killers, in the role that made Lancaster a star), is great as the medical student. As he and Myrna Loy check into the hotel in Turkey, Brent tosses into the air the coin that is the tip for the porter. The porter reaches for the coin, Brent says you mustn't reach, catches the coin first and gives it to the porter. Sort of a mean joke, but an action Herman J. Mankiewicz, the screenwriter or maybe the director, Sam Wood, saw in real life and put into the movie to make Brent's character look authentic. The effort MGM's professional staff put into this fine spy movie shows up on the screen