One reviewer describes this as 'a pretty lame movie' and I am in total agreement. The film often makes little sense and you could certainly do better.
When the film begins, one of two kidnappers accidentally kills the lady they kidnapped. So they come up with a plan that makes absolutely no sense--to kidnap some poor lady and somehow convince the rich guy that the substitute is his daughter. Instead, the idiot kidnaps three nuns and what they do after that makes even less sense. But one of the kidnappers (Lee Majors) balks at his partner (Robert Conrad) when he plans on murdering two of the three nuns. Why only 2 of the 3? I have no idea.
There is nothing about this film that is good or excellent. It often makes little sense and the nuns occasionally behave like morons (especially when they are hiding and one betrays their hiding place by crying out!). Overall, a sloppy, silly movie that rarely does more than pass time.