Ricardo Cortez is a suave jeweler. He buys at auction some famous and expensive diamonds, then takes the Orient Express to Istanbul, so he can romance Mary Astor -- who eventually steals the jewels -- and keep things humming along, with a bunch of people who obviously want the gems and are willing to murder to get them. Apparently.
Robert Florey directs this at the high-speed Warner Brothers pace, even though the plot complexities, which seem to involve everyone actually being someone other than they seem to be, sometimes overwhelm the movie. Like a detective in a pulp novel, I began to suspect everyone, from Parisian chauffeurs -- a shady lot at the best of times -- to children selling gimcrack souvenirs by the side of the train. Why were they traveling on the Orient Express anyway? Don't they know it's a hotbed of espionage, murder, and Kenneth Branagh in a face-eating mustache?
Florey was always fond of Dutch angles, but he can't do much on board the railroad, even with Sidney Hickock as his cinematographer. It was fun while it lasted, but occasionally confusing, as players switched who they were playing.