Anton Walbrook -- still credited as "Adolph" -- is driving his taxicab for his last shift in Budapest before taking a better-paying job. He picks up a fare at the train station, but when he asks which hotel, he discovers that his passenger has been shot.
This sort of thriller was becoming popular in the movies. Hitchcock's efforts like THE MAN WHO KNEW TOO MUCH and LADY ON A TRAIN set the standard. This German variation, co-written by Thea von Harbau, is much more gloomy and Teutonic than Hitchcock's saturnine works and the answer to the mystery is clear before it is offered. It's seventy-five minutes of bombastic anger and fear. If that's your taste, you'll enjoy it. Me, I grew up with Hitchcock's works and I prefer his vicious comic relief.
I've seen some of Walbrook's movies shot in in Vienna in the early 1930s. Soon after this, he moved to England, where he worked under the name of Anton -- Adolf wasn't that popular name in Britain starting in 1939 -- where he specialized in kindly, cynical, world-weary Germans and resumed a wider range when he returned to Continental work after the War. He's good here, but it's a role that a lot of actors could have played well.