From the novel of the same name by Charles Shaw.
A marine and a nun are stranded on an island in WWII after it’s evacuated, and are still there when the Japanese come and occupy it.
This was one of the films we watched on our New Year’s Day Moviefest 2020 (theme: John Huston.)
This was really good! Robert Mitchum (who, I think, has just won promotion to Serious Honey) is perfect for the part of the guy who is trying to do his job and save his country but is falling for this woman he cannot be in love with; Deborah Kerr is a total hottie and very good for the part of the nun who is practical and not at all dainty and girlish, and the growing relationship between them, and the question of where it can/will go, gives as much tension to the movie as the Japanese occupation and their attempts to block that.
Highly recommended, very enjoyable.