Son copain (1950)

Original title: L'inconnue de Montréal

Pierre Chambrac, a French industrialist, and Canadian Paul Laforêt, two former brothers in arms, meet again by chance in Paris five years after the end of World War II. Pierre is engaged to a beautiful foreign young lady by the name of Helen Bering. He introduces her to his friend, which seems to trouble him. To his amazement, Helen and Paul disappear without notice. Pierre, who was beginning to feel jealous, sees his suspicion confirmed. He decides to fly to Montreal where he thinks the couple has taken refuge. Once there, he learns that his dear Helen is actually a criminal and that Paul is a policeman whose duty was to arrest her.