Dr. Ben McKenna (James Stewart) and Jo McKenna (Doris Day) travel to Morocco for a holiday where they meet a mysterious man named Louis Bernard (Daniel Gélin) on a bus.The next day this man is murdered, but before he dies he tells Ben a secret; an assassination will take place in London.The crooks kidnap the couple's son Hank (Christopher Olsen) making sure Ben won't reveal their plan to anybody.Alfred Hitchcock's The Man Who Knew Too Much (1956) is a very intense thriller.The acting is superb as it always is in Hitchcok's films.James Stewart is marvelous.Doris Day is a delightful person and actress and she gets to show her singing talents as well.The song Que Sera, Sera has an important part in the movie.This movie is a movie of many classic scenes.In the final scenes at the Albert Hall, done without dialogue, you can barely blink your eyes.This movie is fifty years old now.Time hasn't decreased its power in any way.