The plot to "Nightmare in the Sun" is a bit hard to believe. After all, we are expected to accept that a lovely young lady (Ursula Andress) is married to an old man (Arthur O'Connell) who moves her to the desert to live. Not surprisingly, she's bored....very bored. As for the husband, he's insanely jealous...so much so that it will end with disaster for his wife as well as an innocent stranger (John Derek) who just wanders into their lives. I could say more, but I don't want to spoil the suspense.
I mentioned above that the film reminded me of "The Postman Always Rings Twice". Both films featured a gorgeous young blonde who inexplicably marries an old coot who moves them to the desert. But apart from this, there are many differences...enough that "Nightmare in the Sun" is still worth seeing.
The most interesting character in the movie is the crooked sheriff played by Aldo Ray. He's a conniving brute and dominates the scenes in which he appears. What also is interesting is how the film features some amazingly talented actors who are barely in the film at all...such as Sammy Davis, Robert Duvall, Keenan Wynn and Richard Jaeckel.
Overall, this is a surprisingly effective thriller. While I never thought John Derek was an especially good actor, here he is just fine as a man on the run from an evil Sheriff. My only complaint is a minor one...the music is often annoying and detracted from the story.