A busload of teenage schoolgirls comprising of the Maidenhill School Girls Choir are being driven through the countryside on their way to a hotel where they hope to stay the night, then the next day attend a singing competition. However, their best laid plans hit a snag when the rather elderly coach that is transporting them starts to feel the strain of such a long journey and has to stop for a rest. A passing jogger, Pete (Anthony Forrest), who is camping in the area tries to help, and he and the driver think they have it fixed, but there are worse things out there than a faulty bus...
Writer and director Alan Birkinshaw followed up one of the worst of the seventies British sex comedies, Confessions of a Sex Maniac, with another tale of debauchery, although this has gone on to rather more acclaim, yet not because it's any good. Indeed, the reason why it has its adherents is down to the poor quality of the enterprise which presented itself as a nasty shocker for grown-ups yet looked as if it had been made by a bunch of amateurs. This in spite of a script which had its dialogue written by Birkinshaw's sister, the famed author Fay Weldon.
Or maybe because of that: often the dialogue was the most ridiculous part. In case you hadn't caught on from that opening, that bunch of schoolgirls, most of whom look to be pushing thirty, are the potential victims of a gang of madmen whose mental afflictions are delineated by a top secret meeting that happens in Whitehall soon after the movie begins. Turns out those four maniacs are the result of an experiment in a hospital in that self same countryside which was intended to soothe their violent impulses by making them act them out in their dreams, the idea being that they won't feel like doing so in real life afterwards.
Bit of a problem with that, as we find out, which is the patients escape thinking they are still in their dream when they are actually awake, so when they start planting axes in people's necks and chopping off dog's legs it's really happening even though they believe they can do anything they wish to those they encounter thanks to this taking place all their heads. So once the schoolgirls end up stranded in a hotel closed for renovations thanks to the bus breaking down for good, the crazies hear their singing and wander over to the mansion, break in, and begin raping and murdering their way through the female cast. If it sounds objectionable, then any offense is swiftly undercut by how absurdly it's all put across.
Take that Weldon dialogue, which no matter her skills on the page here sounds ludicrous and stilted, with the bad guys talking to each other in florid speeches that make them sound like pretentious sports commentators, remarking on how their "dream" has benefits and drawbacks, wondering why they can't think up better food for example. All the girls are pretty much interchangeable after the first half hour in spite of Weldon's efforts, simply there to run away or be saved by the two campers, one of whom has a girlfriend who falls victim to a lunatic when off on her own. There's a germ of an intriguing idea here in that it muses over the sort of things that people conjure up in their fantasies not being anything like what they would get up to in real life, but as the patients in this were raving nutters before then even this stumbles in the face of its laughable qualities. If you like camp, and don't mind unsavoury moments, then Killer's Moon could qualify as a guilty pleasure for some; much of it beggars belief. Music by John Shakespeare and Derek Warne.