So Dark the Night 1946

Synopsis:

Inspector Cassin, a renowned Paris detective, departs to the country for a much-needed break. There he falls in love with the innkeeper’s daughter, Nanette, who is already betrothed to a local farmer. On the evening of their engagement party, Nanette and the farmer both disappear. Cassin takes up the case immediately to discover what happened to them and who is responsible.

Directed by: Joseph H. Lewis
Written by: Dwight V. Babcock & Martin Berkeley & Aubrey Wisberg
Runtime: 71 minutes
Tagline: Most Baffling of Mysteries!
Cast:
Steven Geray
Steven Geray
Henri Cassin 
Micheline Cheirel
Micheline Cheirel
Nanette Michaud 
Eugene Borden
Eugene Borden
Pierre Michaud 
Ann Codee
Ann Codee
Mama Michaud 
Egon Brecher
Egon Brecher
Dr. Boncourt 
Helen Freeman
Helen Freeman
Widow Bridelle