First and Last, "I Saw Her"

the first and last image from a classic movie


Can you guess the movie?

If you need a hint, here are the first and last lines of dialogue:
First Lines "Monsieur ______"
"Yes?"
"It's about time you blew your horn."
Last Line "I saw her. I know that I saw her."

Highlight for the answer if you're still stuck: LES DIABOLIQUES (1955)