Directed by: Alfred Hitchcock
Starring: Robert Donat, Lucie Mannheim, Godfrey Tearle, Madeleine Carroll
Character mistake: The Professor refers to his pistol as a "revolver" but it is a semi-auto.
Character mistake: During Mr Memory's act at the beginning of the film, he gives the answer regarding the last British heavyweight boxing champion and then says, "Am I right, sir?", but the question was asked by a woman.
Revealing mistake: The serial number of the autogyro has been reversed, showing that the stock shot has been reversed for effect.
Trivia: Director Alfred Hitchcock has a cameo role in this film - he is seen tossing some litter as Richard and Annabella run from the music hall.