Revealing mistake: The landscape seen through the window of the train as the Frankensteins travel repeats itself several times.
Son of Frankenstein (1939)
Ending / spoiler
Directed by: Rowland V. Lee
Starring: Boris Karloff, Basil Rathbone, Bela Lugosi, Lionel Atwill
Wolf von Frankenstein (Basil Rathbone) pushes the Creature (Boris Karloff) into molten lava that's in a cave below the laboratory. Wolf hands over the Frankenstein estate to the townspeople and leaves the country with his wife and son.
LaForce
More mistakes in Son of Frankenstein
Amelia: When the house is filled with dread, place the beds at head to head.
Trivia: Originally planned to be filmed in color but that was dropped. Some say it was because of the high costs of color film and cameras. Others say that the Karloff monster makeup, grey-green greasepaint worked for black and white lighting and filming, but looked ridiculous in color. There are surviving home movies made during the filming of Son, showing Karloff in his makeup and vest. You can decide if the right decision was made.