This is a film I’d NEVER heard of, BUT was curious to see (since it has both Hepburn and Mitchum). It was shown on TCM last week and is directed by the famed Vincente Minnelli (husband of Judy Garland and father to Liza). Minnelli does a VERY good job w/ a domestic drama mixed w/ film noir, which is NOT something you’d expect if you know his more well-known works (Meet Me in St. Louis, Father of the Bride, Gigi). He also directed The Bad and the Beautiful, which shows the dark side of Hollywood.
Hepburn is cast against type here, which fans (like me) may enjoy, and even some haters will be pleasantly surprised to see. She plays Ann Hamilton, the quirky/single daughter of small-town professor, Dink (Edmund Gwenn from Miracle on 34th Street). Ann prefers playing w/ her dog and tinkering in her home chemistry lab, eschewing ideas of marriage pushed upon her by cranky housekeeper, Lucy (Marjorie Main) and eager academic, Prof. Bangs (Dan Tobin).
 Call it Film-Noir. Call it Mystery/Suspense. Call it Psychological Thriller. Call it what you may…I call it: absorbing drama.
It moves very deliberately… and the facts are revealed one by one, in true mystery fashion, until the fantastic, thrilling ending.
 Hepburn gives her usual intelligent performance, showing a vulnerable, feminine side that is very appealing. There is a scene in a fitting room where she is absolutely stunning. The scenes between her and her father, played by Edmund Gwenn, are delightful and realistic…
 As others have noted, the plot has “Rebecca-esque” qualities, but a character completely its own.
-Various IMDB comments
One night, Ann’s life is changed when she meets Alan Garroway (Robert Taylor), a suave/dapper inventor who was meeting w/ Dink. It turns out that his company helped win WWII w/ a cutting-edge missile guidance system. Ann is struck by him at first sight; it’s obvious that he is interested, too. Soon, they’re married and off to DC! Ann meets his (high society) friends, gets a new/stylish wardrobe, and learns that her new husband is more complicated than she thought.
BOTH Taylor and Mitchum were younger than Hepburn.
In Minnelli‘s autobiography, he says that Mitchum was very uncomfortable in the role of the sensitive Michael.
Katharine Hepburn and Robert Mitchum did NOT get along during the filming. One day, Hepburn told Mitchum, “You know you can’t act, and if you hadn’t been good looking you would never have got a picture at all. I’m tired of working with people like you who have nothing to offer.” (OUCH!)