Deadly Strangers [1974] [DVD]

A man and woman meet on the side of a road and decide to share a ride. It is revealed that there is a raving psychopath on the loose and it is pretty obvious that it is one of these two people.

An effective suspense story with terrific performances by Hayley Mills and Simon Ward. Though the story may at first seem like a transparent / psycho-on-the-loose chiller, the film has some strikingly effective new twists, and there are enough red herrings for two films!