The man who knew too much

Dr. Ben and Joe McKenna, ordinary, unsuspecting tourists, are traveling to Morocco for a vacation. Together with their son Hank, they enjoy their holiday when they meet Mr. and Mrs. Drayton, an English couple, and Louis Bernard, a suspicious but friendly Frenchman.

Later, while Ben and Joe are walking through the market, an Arab runs up to them with a knife in his back. Ben literally catches the falling Arab and, to his horror, recognizes him as disguised Louis Bernard. The Frenchman manages to whisper something to Ben before dying, drawing him into the center of an international conspiracy whose participants aim to assassinate a high-ranking official. Only Ben can stop the events from unfolding. Hitchcock himself appears in the film in a cameo role, as does his composer, Bernard Herrmann.