It's a husband-stealing whodunit that features moment of poignancy and insight.
The film (which was written and directed by Joseph L. Mankiewicz who would win back to back writing and directing Oscars for this film and All About Eve the following year) tells the story of three friends, Deborah (Jeanne Craine), Rita (Ann Sothern), and Lora Mae (Linda Darnell) who are about to take a group of children on a riverboat trip when they receive a letter, informing them that that Addie Ross, a mutual friend/enemy has run off with one of their husbands.
The film then offers flashbacks that give us some insight into the marriage of all three women and the issues that could possibly propel their husbands into the arms of another woman. When it comes to Deborah, a sheltered farmgirl who married her social superior and feels out of place at the fancy outings and parties that her husband loves. Rita writes stories for the radio, which causes friction between her husband since she makes a substantial portion of the family's income and focuses more on the radio station's needs than her husbands. And Lora Mae is married to an older, wealthy man she forced into marriage.
One aspect in which the film works is that neither marriage is shown to be truly broken, in fact, we pretty much get the pros and cons of all the relationships in these little vignettes. While the men all have issues that may drive them away from their wives, they're also shown to love their female partners and be supportive of them. So it adds a great deal of suspense as to who has run off with the never-seen Addie, since it's not really obvious.
The three lead actresses all turn in great performances, with each wife creating a distinct personality and effectively conveying doubt and worry while agonizing over their potentially dead marriage. And the writing is sharp and smart, never bogging itself down in the cliches that could easily arise from the story, which is no surprise since the script was penned by someone who would go on to write what could be considered the greatest screenplay ever written.
This is a wonderful little film that doesn't really get much attention, so do yourself a favor and watch it.