Mr. Gregoire Runs Away(1946)

Alex Grégoire is a timid insurance company clerk who shares his uneventful life between his wife Angèle, his colleagues and his passion for crosswords. But all of a sudden his existence changes dramatically. First because he wins a crossword competition. Second because a jewel thief, Charles Tuffal, thinks he recognizes in him a former accomplice. From that moment "uneventful" is not the best adjective to qualify Alex's life anymore...