The Locket is a 1946 film noir directed by John Brahm, starring Laraine Day, Brian Aherne, Robert Mitchum, and Gene Raymond, and released by RKO Pictures. The film is based on a screenplay by Sheridan Gibney, adapted from "What Nancy Wanted" by Norma Barzman, wife of later-blacklisted writer Ben Barzman. It is noted for its complex use of layered flashbacks (flashbacks within flashbacks) to give psychological depth to the narrative. Wikipedia
Mrs. Wendall: Do you approve of foolish marriages? Mr. Wendall: Certainly. They alienate relatives.