Fear In The Night
1972

Fear In The Night really qualifies as a thriller more than a horror, but one or two suitably spooky touches put it, I believe, more in the horror vein.
For a start, there's Peter Cushing as a nutty head teacher, Ralph Bates as a vague-looking "young" man with a bad haircut (nothing new there, then) and Joan Collins playing, you guessed it, a bitch. Chuck in scream queen Judy Geeson and you end up with a pretty much archetypal 70s British horror cast. So there.
The film starts with the sound of choirboys singing a hymn as the camera pans over the outside of a public school, eventually alighting on a body hanging from a tree. Nice start.
Ralph and Judy, newly weds, arrive at the school, where he is a teacher. But there's hardly anyone else there - just Peter and Joan. Joan, who likes nothing more than going out and killing things with a shotgun, is Peter's wife - but something's obviously wrong with the marriage.
Something's wrong with the school as well - there are no kids there, although a ghostly choir can be heard. For some reason, Judy, who is recovering from a nervous breakdown, seems to think this isn't particularly strange - but she soon changes her mind when the one-armed man she has been stalked by appears to be none other than Cushing himself. Of course, there's much more to what's going on than meets the eye - with some suitably bizarre twists along the way. Definitely one worth looking out for amongst the late night TV schedules.

Fear in the Night (1972)
Director: Jimmy Sangster Writer(s): Jimmy Sangster Michael Syson
Credited Cast: Judy Geeson - Peggy Heller, Joan Collins - Molly Carmichael, Ralph Bates - Robert Heller, Peter Cushing - Michael Carmichael, John Bown - 1st Policeman, James Cossins - The Doctor, Brian Grellis - 2nd Policeman, Gillian Lind - Mrs. Beamish