A Serious Man, Opening Sequence (2009)

Directors: Joel and Ethan Coen. The film starts with a ten minute Yiddish folk tale about a man who invites a guest home, only for his wife to insist the guest is a 'dybbuk' (an undead spirit) and stab him with a soup pick. The bleeding guest continues to act normally, even hysterically laughing, leaving the question 'is he or isn't he?' unanswered.