The Demon (1981)

This 1981 South African offering, also known as Midnight Caller, is either a partially completed film that's had 50 minutes of unrelated footage added to make it up to feature length, or one of the most comically inept films I've seen in a while, or both.

Quite probably both.

The film begins with a masked man breaking into the house of a mother and her teenage daughter.  He ties up the mother and puts a plastic bag over her head, then abducts the younger woman.  Fortunately for mom, dad gets home in time to save her from asphyxiation, but by then their daughter is long gone.  When the cops fail to find the missing girl, the grieving couple hire a psychic former marine (not something you write every day) to look for her.

Meanwhile, we see that the killer has started stalking an attractive young school teacher.  By which I mean "she keeps catching glimpses of him, even in places he couldn't actually be standing".  Whether this "he's somewhere he couldn't be" thing is paranoid delusion, or killer super powers, will go unresolved.  But that's okay, this is a movie which can't decide from shot to shot whether or not the killer wears a mask.  I mean literally shot to shot: at the end of the film, when the final girl stabs him, we can clearly see his face.  He then falls into the bath.  Another clear shot of his face.  We cut away, cut back: plastic mask, clear as day.

Yes, I did just spoil the end of the film.  It's not like you're missing anything.

So how do the psychic and the school teacher cross paths?  Answer: they don't.  Like I said, it's almost like this is two completely separate bits of film that have been jammed together (which is not unknown to happen).  The psychic investigates for a while and starts to get close to the killer, but then one of his clients shoots him in the head, under the delusion that the psychic was the real killer all along.  This happens a good half hour before the movie ends - got to fit in an extended sequence of the topless school teacher being chased around her house by the bad guy, after all - and is then never mentioned again.

There are one or two neat ideas in this: for instance I liked how at one point the school teacher tried to escape by climbing up into the ceiling and levering up tiles on the roof, and the way she finally gets the drop on the killer is fun if very contrived.  But really, unless you're the kind of person who would want to marvel at the fundamental incompetence of it all, you can skip it.