So Dark the Night (1946)

A renowned, relentless Paris detective takes his first vacation in 11 years at a small inn in the French countryside. There he meets and falls in love with the hotelier's daughter, who is betrothed to a neighboring farmer but hopes to marry him and move to Paris. On the evening of their engagement, both the fiancée and the farmer disappear. What has happened to them? Who is responsible? Can the famed detective apply his talents to a rural mystery?