Mississippi Mermaid (1969), directed by François Truffaut.
An arranged bride, known to her future husband only through letters, arrives on Réunion island in the Indian Ocean. His surprise for her: he's not an employee of the tobacco plantation and cigarette factory: he owns it all and is quite wealthy.
She has surprises, too. Although quite beautiful, she doesn't look anything like her photo. The ring made for her doesn't fit, and she is afraid of the dark and has night terrors. As clues of something very wrong accumulate, the music cues us that all is not as it appears.
One day he finds his bank accounts have been cleaned out and she is gone. For revenge he burns her underwear and buys a gun. They will meet again, but their story is far from over even then.
A tale of of obsessive love. Truffaut is the director who loved women, and he understands. He also loved Hitchcock and has an homage delirium scene. He uses his favorite name -- "Julie" -- but her real name is Marion, like Marion Crane in Psycho (1960).
As the commentary track points out, Catherine Deneuve may not be a great actress, but her beauty makes her a great movie star, and we enjoy her on that level. She's a nasty piece of work here: murder makes her horny.
Misc notes:
The arranged bride arriving at a remote plantation reminds one of The Naked Jungle (1954).
The name of the boat bringing her to the island is "The Mississippi", which is confusing; the movie has nothing to do with America otherwise.
The English title is poorly chosen. The French word is "siren", the alluring women who lure sailors to their deaths. Mermaids just sit on the rocks and comb their hair. The original novel was "Waltz into Darkness" by Cornell Woolrich (aka William Irish).
Filmed on location in France and on Réunion island.
Remade in 2001 as Original Sin with Angelina Jolie and Antonio Banderas.
Available on Blu-ray from Twilight Time with a commentary by the usual crew. Unusually, the English subtitles are burned into the image.